mm/madvise: move up the behavior parameter validation
madvise_behavior_valid() should be called before acting upon the
behavior parameter. Hence move up the function. This also includes
MADV_SOFT_OFFLINE and MADV_HWPOISON options as valid behavior parameter
for the system call madvise().
mm/madvise.c: clean up MADV_SOFT_OFFLINE and MADV_HWPOISON
This cleans up handling MADV_SOFT_OFFLINE and MADV_HWPOISON called
through madvise() system call.
* madvise_memory_failure() was misleading to accommodate handling of
both memory_failure() as well as soft_offline_page() functions.
Basically it handles memory error injection from user space which
can go either way as memory failure or soft offline. Renamed as
madvise_inject_error() instead.
* Renamed struct page pointer 'p' to 'page'.
* pr_info() was essentially printing PFN value but it said 'page'
which was misleading. Made the process virtual address explicit.
Before the patch:
Soft offlining page 0x15e3e at 0x3fff8c230000
Soft offlining page 0x1f3 at 0x3fffa0da0000
Soft offlining page 0x744 at 0x3fff7d200000
Soft offlining page 0x1634d at 0x3fff95e20000
Soft offlining page 0x16349 at 0x3fff95e30000
Soft offlining page 0x1d6 at 0x3fff9e8b0000
Soft offlining page 0x5f3 at 0x3fff91bd0000
Injecting memory failure for page 0x15c8b at 0x3fff83280000
Injecting memory failure for page 0x16190 at 0x3fff83290000
Injecting memory failure for page 0x740 at 0x3fff9a2e0000
Injecting memory failure for page 0x741 at 0x3fff9a2f0000
After the patch:
Soft offlining pfn 0x1484e at process virtual address 0x3fff883c0000
Soft offlining pfn 0x1484f at process virtual address 0x3fff883d0000
Soft offlining pfn 0x14850 at process virtual address 0x3fff883e0000
Soft offlining pfn 0x14851 at process virtual address 0x3fff883f0000
Soft offlining pfn 0x14852 at process virtual address 0x3fff88400000
Soft offlining pfn 0x14853 at process virtual address 0x3fff88410000
Soft offlining pfn 0x14854 at process virtual address 0x3fff88420000
Soft offlining pfn 0x1521c at process virtual address 0x3fff6bc70000
Injecting memory failure for pfn 0x10fcf at process virtual address 0x3fff86310000
Injecting memory failure for pfn 0x10fd0 at process virtual address 0x3fff86320000
Injecting memory failure for pfn 0x10fd1 at process virtual address 0x3fff86330000
Injecting memory failure for pfn 0x10fd2 at process virtual address 0x3fff86340000
Injecting memory failure for pfn 0x10fd3 at process virtual address 0x3fff86350000
Injecting memory failure for pfn 0x10fd4 at process virtual address 0x3fff86360000
Injecting memory failure for pfn 0x10fd5 at process virtual address 0x3fff86370000
Johannes Weiner [Wed, 3 May 2017 21:55:03 +0000 (14:55 -0700)]
mm: vmscan: fix IO/refault regression in cache workingset transition
Since commit 59dc76b0d4df ("mm: vmscan: reduce size of inactive file
list") we noticed bigger IO spikes during changes in cache access
patterns.
The patch in question shrunk the inactive list size to leave more room
for the current workingset in the presence of streaming IO. However,
workingset transitions that previously happened on the inactive list are
now pushed out of memory and incur more refaults to complete.
This patch disables active list protection when refaults are being
observed. This accelerates workingset transitions, and allows more of
the new set to establish itself from memory, without eating into the
ability to protect the established workingset during stable periods.
The workloads that were measurably affected for us were hit pretty bad
by it, with refault/majfault rates doubling and tripling during cache
transitions, and the machines sustaining half-hour periods of 100% IO
utilization, where they'd previously have sub-minute peaks at 60-90%.
Stateful services that handle user data tend to be more conservative
with kernel upgrades. As a result we hit most page cache issues with
some delay, as was the case here.
The severity seemed to warrant a stable tag.
Fixes: 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list") Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mmap: replace SHM_HUGE_MASK with MAP_HUGE_MASK inside mmap_pgoff
Commit 091d0d55b286 ("shm: fix null pointer deref when userspace
specifies invalid hugepage size") had replaced MAP_HUGE_MASK with
SHM_HUGE_MASK. Though both of them contain the same numeric value of
0x3f, MAP_HUGE_MASK flag sounds more appropriate than the other one in
the context. Hence change it back.
Link: http://lkml.kernel.org/r/20170404045635.616-1-khandual@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:54:57 +0000 (14:54 -0700)]
oom: improve oom disable handling
Tetsuo has reported that sysrq triggered OOM killer will print a
misleading information when no tasks are selected:
sysrq: SysRq : Manual OOM execution
Out of memory: Kill process 4468 ((agetty)) score 0 or sacrifice child
Killed process 4468 ((agetty)) total-vm:43704kB, anon-rss:1760kB, file-rss:0kB, shmem-rss:0kB
sysrq: SysRq : Manual OOM execution
Out of memory: Kill process 4469 (systemd-cgroups) score 0 or sacrifice child
Killed process 4469 (systemd-cgroups) total-vm:10704kB, anon-rss:120kB, file-rss:0kB, shmem-rss:0kB
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
sysrq: SysRq : Manual OOM execution
sysrq: OOM request ignored because killer is disabled
The real reason is that there are no eligible tasks for the OOM killer
to select but since commit 7c5f64f84483 ("mm: oom: deduplicate victim
selection code for memcg and global oom") the semantic of out_of_memory
has changed without updating moom_callback.
This patch updates moom_callback to tell that no task was eligible which
is the case for both oom killer disabled and no eligible tasks. In
order to help distinguish first case from the second add printk to both
oom_killer_{enable,disable}. This information is useful on its own
because it might help debugging potential memory allocation failures.
Fixes: 7c5f64f84483 ("mm: oom: deduplicate victim selection code for memcg and global oom") Link: http://lkml.kernel.org/r/20170404134705.6361-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Wed, 3 May 2017 21:54:54 +0000 (14:54 -0700)]
userfaultfd: selftest: combine all cases into a single executable
Currently, selftest for userfaultfd is compiled three times: for
anonymous, shared and hugetlb memory. Let's combine all the cases into
a single executable which will have a command line option for selection
of the test type.
Link: http://lkml.kernel.org/r/1490869741-5913-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vinayak Menon [Wed, 3 May 2017 21:54:42 +0000 (14:54 -0700)]
mm: enable page poisoning early at boot
On SPARSEMEM systems page poisoning is enabled after buddy is up,
because of the dependency on page extension init. This causes the pages
released by free_all_bootmem not to be poisoned. This either delays or
misses the identification of some issues because the pages have to
undergo another cycle of alloc-free-alloc for any corruption to be
detected.
Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON
flag. Since all the free pages will now be poisoned, the flag need not
be verified before checking the poison during an alloc.
Huang Ying [Wed, 3 May 2017 21:54:39 +0000 (14:54 -0700)]
mm, swap: avoid lock swap_avail_lock when held cluster lock
Cluster lock is used to protect the swap_cluster_info and corresponding
elements in swap_info_struct->swap_map[]. But it is found that now in
scan_swap_map_slots(), swap_avail_lock may be acquired when cluster lock
is held. This does no good except making the locking more complex and
improving the potential locking contention, because the
swap_info_struct->lock is used to protect the data structure operated in
the code already. Fix this via moving the corresponding operations in
scan_swap_map_slots() out of cluster lock.
Link: http://lkml.kernel.org/r/20170317064635.12792-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Tim Chen <tim.c.chen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Wed, 3 May 2017 21:54:36 +0000 (14:54 -0700)]
mm, swap: improve readability via make spin_lock/unlock balanced
This is just a cleanup patch, no functionality change.
In cluster_list_add_tail(), spin_lock_nested() is used to lock the
cluster, while unlock_cluster() is used to unlock the cluster. To
improve the code readability, use spin_unlock() directly to unlock the
cluster.
Link: http://lkml.kernel.org/r/20170317064635.12792-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Tim Chen <tim.c.chen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Wed, 3 May 2017 21:54:33 +0000 (14:54 -0700)]
mm, swap: fix comment in __read_swap_cache_async
Commit cbab0e4eec29 ("swap: avoid read_swap_cache_async() race to
deadlock while waiting on discard I/O completion") fixed a deadlock in
read_swap_cache_async(). Because at that time, in swap allocation path,
a swap entry may be set as SWAP_HAS_CACHE, then wait for discarding to
complete before the page for the swap entry is added to the swap cache.
But in commit 815c2c543d3a ("swap: make swap discard async"), the
discarding for swap become asynchronous, waiting for discarding to
complete will be done before the swap entry is set as SWAP_HAS_CACHE.
So the comments in code is incorrect now. This patch fixes the
comments.
The cond_resched() added in the commit cbab0e4eec29 is not necessary now
too. But if we added some sleep in swap allocation path in the future,
there may be some hard to debug/reproduce deadlock bug. So it is kept.
Link: http://lkml.kernel.org/r/20170317064635.12792-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Shaohua Li <shli@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 3 May 2017 21:54:27 +0000 (14:54 -0700)]
mm: make rmap_one boolean function
rmap_one's return value controls whether rmap_work should contine to
scan other ptes or not so it's target for changing to boolean. Return
true if the scan should be continued. Otherwise, return false to stop
the scanning.
This patch makes rmap_one's return value to boolean.
Link: http://lkml.kernel.org/r/1489555493-14659-10-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 3 May 2017 21:54:17 +0000 (14:54 -0700)]
mm: remove SWAP_AGAIN in ttu
In 2002, [1] introduced SWAP_AGAIN. At that time, try_to_unmap_one used
spin_trylock(&mm->page_table_lock) so it's really easy to contend and
fail to hold a lock so SWAP_AGAIN to keep LRU status makes sense.
However, now we changed it to mutex-based lock and be able to block
without skip pte so there is few of small window to return SWAP_AGAIN so
remove SWAP_AGAIN and just return SWAP_FAIL.
Minchan Kim [Wed, 3 May 2017 21:54:13 +0000 (14:54 -0700)]
mm: remove SWAP_MLOCK in ttu
ttu doesn't need to return SWAP_MLOCK. Instead, just return SWAP_FAIL
because it means the page is not-swappable so it should move to another
LRU list(active or unevictable). putback friends will move it to right
list depending on the page's LRU flag.
Link: http://lkml.kernel.org/r/1489555493-14659-6-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 3 May 2017 21:54:10 +0000 (14:54 -0700)]
mm: make try_to_munlock() return void
try_to_munlock returns SWAP_MLOCK if the one of VMAs mapped the page has
VM_LOCKED flag. In that time, VM set PG_mlocked to the page if the page
is not pte-mapped THP which cannot be mlocked, either.
With that, __munlock_isolated_page can use PageMlocked to check whether
try_to_munlock is successful or not without relying on try_to_munlock's
retval. It helps to make try_to_unmap/try_to_unmap_one simple with
upcoming patches.
Minchan Kim [Wed, 3 May 2017 21:54:07 +0000 (14:54 -0700)]
mm: remove SWAP_MLOCK check for SWAP_SUCCESS in ttu
If the page is mapped and rescue in try_to_unmap_one, the
page_mapcount() of a page cannot be zero, so the page_mapcount check in
try_to_unmap is enough to return SWAP_SUCCESS. IOW, SWAP_MLOCK check is
redundant so remove it.
Link: http://lkml.kernel.org/r/1489555493-14659-4-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 3 May 2017 21:54:04 +0000 (14:54 -0700)]
mm: remove SWAP_DIRTY in ttu
If we found lazyfree page is dirty, try_to_unmap_one can just
SetPageSwapBakced in there like PG_mlocked page and just return with
SWAP_FAIL which is very natural because the page is not swappable right
now so that vmscan can activate it. There is no point to introduce new
return value SWAP_DIRTY in try_to_unmap at the moment.
Link: http://lkml.kernel.org/r/1489555493-14659-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yisheng Xie [Wed, 3 May 2017 21:53:57 +0000 (14:53 -0700)]
mm/vmscan: more restrictive condition for retry in do_try_to_free_pages
By reviewing code, I find that when enter do_try_to_free_pages, the
may_thrash is always clear, and it will retry shrink zones to tap
cgroup's reserves memory by setting may_thrash when the former
shrink_zones reclaim nothing.
However, when memcg is disabled or on legacy hierarchy, or there do not
have any memcg protected by low limit, it should not do this useless
retry at all, for we do not have any cgroup's reserves memory to tap,
and we have already done hard work but made no progress, which as Michal
pointed out in former version, we are trying hard to control the retry
logical of page alloctor, and the current additional round of reclaim is
just lame.
Therefore, to avoid this unneeded retrying and make code more readable,
we remove the may_thrash field in scan_control, instead, introduce
memcg_low_reclaim and memcg_low_skipped, and only retry when
memcg_low_skipped, by setting memcg_low_reclaim.
[xieyisheng1@huawei.com: remove may_thrash field, introduce mem_cgroup_reclaim] Link: http://lkml.kernel.org/r/1490191893-5923-1-git-send-email-ysxie@foxmail.com Link: http://lkml.kernel.org/r/1490191893-5923-1-git-send-email-ysxie@foxmail.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Michal Hocko <mhocko@kernel.org> Suggested-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yisheng Xie [Wed, 3 May 2017 21:53:54 +0000 (14:53 -0700)]
mm/compaction: ignore block suitable after check large free page
By reviewing code, I find that if the migrate target is a large free
page and we ignore suitable, it may splite large target free page into
smaller block which is not good for defrag. So move the ignore block
suitable after check large free page.
As Vlastimil pointed out in RFC version that this patch is just based on
logical analyses which might be better for future-proofing the function
and it is most likely won't have any visible effect right now, for
direct compaction shouldn't have to be called if there's a
>=pageblock_order page already available.
Link: http://lkml.kernel.org/r/1489490743-5364-1-git-send-email-xieyisheng1@huawei.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wei Yang [Wed, 3 May 2017 21:53:51 +0000 (14:53 -0700)]
mm/sparse: refine usemap_size() a little
The current implementation calculates usemap_size in two steps:
* calculate number of bytes to cover these bits
* calculate number of "unsigned long" to cover these bytes
It would be more clear by:
* calculate number of "unsigned long" to cover these bits
* multiple it with sizeof(unsigned long)
This patch refine usemap_size() a little to make it more easy to
understand.
__GFP_NOWARN, which is usually added to avoid warnings from callsites
that expect to fail and have fallbacks, currently also suppresses
allocation stall warnings. These trigger when an allocation is stuck
inside the allocator for 10 seconds or longer.
But there is no class of allocations that can get legitimately stuck in
the allocator for this long. This always indicates a problem.
Always emit stall warnings. Restrict __GFP_NOWARN to alloc failures.
Link: http://lkml.kernel.org/r/20170125181150.GA16398@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 3 May 2017 21:53:45 +0000 (14:53 -0700)]
mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx
kswapd is woken to reclaim a node based on a failed allocation request
from any eligible zone. Once reclaiming in balance_pgdat(), it will
continue reclaiming until there is an eligible zone available for the
zone it was woken for. kswapd tracks what zone it was recently woken
for in pgdat->kswapd_classzone_idx. If it has not been woken recently,
this zone will be 0.
However, the decision on whether to sleep is made on
kswapd_classzone_idx which is 0 without a recent wakeup request and that
classzone does not account for lowmem reserves. This allows kswapd to
sleep when a low small zone such as ZONE_DMA is balanced for a GFP_DMA
request even if a stream of allocations cannot use that zone. While
kswapd may be woken again shortly in the near future there are two
consequences -- the pgdat bits that control congestion are cleared
prematurely and direct reclaim is more likely as kswapd slept
prematurely.
This patch flips kswapd_classzone_idx to default to MAX_NR_ZONES (an
invalid index) when there has been no recent wakeups. If there are no
wakeups, it'll decide whether to sleep based on the highest possible
zone available (MAX_NR_ZONES - 1). It then becomes critical that the
"pgdat balanced" decisions during reclaim and when deciding to sleep are
the same. If there is a mismatch, kswapd can stay awake continually
trying to balance tiny zones.
simoop was used to evaluate it again. Two of the preparation patches
regressed the workload so they are included as the second set of
results. Otherwise this patch looks artifically excellent
With this patch on top, write and allocation latencies are massively
improved. The read latencies are slightly impaired but it's worth
noting that this is mostly due to the IO scheduler and not directly
related to reclaim. The vmstats are a bit of a mix but the relevant
ones are as follows;
Direct reclaim is reduced but not eliminated. It's worth noting that
there are two periods of direct reclaim for this workload. The first is
when it switches from preparing the files for the actual test itself.
It's a lot of file IO followed by a lot of allocs that reclaims heavily
for a brief window. While direct reclaim is lower with clear-v2, it is
due to kswapd scanning aggressively and trying to reclaim the world
which is not the right thing to do. With the patches applied, there is
still direct reclaim but the phase change from "creating work files" to
starting multiple threads that allocate a lot of anonymous memory faster
than kswapd can reclaim.
Scanning/reclaim efficiency is restored by this patch.
Page writes from reclaim context are back at 0 which is ideal.
Pages immediately reclaimed after IO completes is slightly improved but
it is expected this will vary slightly.
On UMA, there is almost no change so this is not expected to be a
universal win.
Mel Gorman [Wed, 3 May 2017 21:53:41 +0000 (14:53 -0700)]
mm, vmscan: only clear pgdat congested/dirty/writeback state when balanced
A pgdat tracks if recent reclaim encountered too many dirty, writeback
or congested pages. The flags control whether kswapd writes pages back
from reclaim context, tags pages for immediate reclaim when IO
completes, whether processes block on wait_iff_congested and whether
kswapd blocks when too many pages marked for immediate reclaim are
encountered.
The state is cleared in a check function with side-effects. With the
patch "mm, vmscan: fix zone balance check in prepare_kswapd_sleep", the
timing of when the bits get cleared changed. Due to the way the check
works, it'll clear the bits if ZONE_DMA is balanced for a GFP_DMA
allocation because it does not account for lowmem reserves properly.
For the simoop workload, kswapd is not stalling when it should due to
the premature clearing, writing pages from reclaim context like crazy
and generally being unhelpful.
This patch resets the pgdat bits related to page reclaim only when
kswapd is going to sleep. The comparison with simoop is then
Read latency is improved, write latency is mostly improved but
allocation latency is regressed. kswapd is still reclaiming
inefficiently, pages are being written back from writeback context and a
host of other issues. However, given the change, it needed to be
spelled out why the side-effect was moved.
Shantanu Goel [Wed, 3 May 2017 21:53:38 +0000 (14:53 -0700)]
mm, vmscan: fix zone balance check in prepare_kswapd_sleep
Patch series "Reduce amount of time kswapd sleeps prematurely", v2.
The series is unusual in that the first patch fixes one problem and
introduces other issues that are noted in the changelog. Patch 2 makes
a minor modification that is worth considering on its own but leaves the
kernel in a state where it behaves badly. It's not until patch 3 that
there is an improvement against baseline.
This was mostly motivated by examining Chris Mason's "simoop" benchmark
which puts the VM under similar pressure to HADOOP. It has been
reported that the benchmark has regressed severely during the last
number of releases. While I cannot reproduce all the same problems
Chris experienced due to hardware limitations, there was a number of
problems on a 2-socket machine with a single disk.
These are latencies. Read/write are threads reading fixed-size random
blocks from a simulated database. The allocation latency is mmaping and
faulting regions of memory. The p50, 95 and p99 reports the worst
latencies for 50% of the samples, 95% and 99% respectively.
For example, the report indicates that while the test was running 99% of
writes completed 99.75% faster. It's worth noting that on a UMA machine
that no difference in performance with simoop was observed so milage
will vary.
It's noted that there is a slight impact to read latencies but it's
mostly due to IO scheduler decisions and offset by the large reduction
in other latencies.
This patch (of 3):
The check in prepare_kswapd_sleep needs to match the one in
balance_pgdat since the latter will return as soon as any one of the
zones in the classzone is above the watermark. This is specially
important for higher order allocations since balance_pgdat will
typically reset the order to zero relying on compaction to create the
higher order pages. Without this patch, prepare_kswapd_sleep fails to
wake up kcompactd since the zone balance check fails.
It was first reported against 4.9.7 that kswapd is failing to wake up
kcompactd due to a mismatch in the zone balance check between
balance_pgdat() and prepare_kswapd_sleep().
balance_pgdat() returns as soon as a single zone satisfies the
allocation but prepare_kswapd_sleep() requires all zones to do +the
same. This causes prepare_kswapd_sleep() to never succeed except in the
order == 0 case and consequently, wakeup_kcompactd() is never called.
For the machine that originally motivated this patch, the state of
compaction from /proc/vmstat looked this way after a day and a half +of
uptime:
Further notes from Mel that motivated him to pick this patch up and
resend it;
It was observed for the simoop workload (pressures the VM similar to
HADOOP) that kswapd was failing to keep ahead of direct reclaim. The
investigation noted that there was a need to rationalise kswapd
decisions to reclaim with kswapd decisions to sleep. With this patch on
a 2-socket box, there was a 49% reduction in direct reclaim scanning.
However, the impact otherwise is extremely negative. Kswapd reclaim
efficiency dropped from 98% to 76%. simoop has three latency-related
metrics for read, write and allocation (an anonymous mmap and fault).
Of greater concern is that the patch causes swapping and page writes
from kswapd context rose from 0 pages to 4189753 pages during the hour
the workload ran for. By and large, the patch has very bad behaviour
but easily missed as the impact on a UMA machine is negligible.
This patch is included with the data in case a bisection leads to this
area. This patch is also a pre-requisite for the rest of the series.
Minchan Kim [Wed, 3 May 2017 21:53:35 +0000 (14:53 -0700)]
mm: do not use double negation for testing page flags
With the discussion[1], I found it seems there are every PageFlags
functions return bool at this moment so we don't need double negation
any more. Although it's not a problem to keep it, it makes future users
confused to use double negation for them, too.
Frankly sepaking, I like every PageFlags to return bool instead of int.
It will make it clear. AFAIR, Chen Gang had tried it but don't know why
it was not merged at that time.
Kees Cook [Wed, 3 May 2017 21:53:32 +0000 (14:53 -0700)]
mm: remove rodata_test_data export, add pr_fmt
Since commit 3ad38ceb2769 ("x86/mm: Remove CONFIG_DEBUG_NX_TEST"),
nothing is using the exported rodata_test_data variable, so drop the
export.
This additionally updates the pr_fmt to avoid redundant strings and
adjusts some whitespace.
Link: http://lkml.kernel.org/r/20170307005313.GA85809@beast Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Jinbum Park <jinb.park7@gmail.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we change round_up() to ((x) + __round_mask(x, y)) & ~__round_mask(x, y)
then GCC can see through it and remove the mask (because that would be
dead code given the subsequent shift):
But that's problematic because we'd evaluate 'y' twice. Converting
round_up into an inline function prevents it from being used in other
definitions. The easiest thing to do is just change these three usages
of round_up to use DIV_ROUND_UP. Also add an unlikely() because GCC's
heuristic is wrong in this case.
Michal Hocko [Wed, 3 May 2017 21:53:26 +0000 (14:53 -0700)]
jbd2: make the whole kjournald2 kthread NOFS safe
kjournald2 is central to the transaction commit processing. As such any
potential allocation from this kernel thread has to be GFP_NOFS. Make
sure to mark the whole kernel thread GFP_NOFS by the memalloc_nofs_save.
[akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170306131408.9828-8-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:53:22 +0000 (14:53 -0700)]
jbd2: mark the transaction context with the scope GFP_NOFS context
now that we have memalloc_nofs_{save,restore} api we can mark the whole
transaction context as implicitly GFP_NOFS. All allocations will
automatically inherit GFP_NOFS this way. This means that we do not have
to mark any of those requests with GFP_NOFS and moreover all the
ext4_kv[mz]alloc(GFP_NOFS) are also safe now because even the hardcoded
GFP_KERNEL allocations deep inside the vmalloc will be NOFS now.
[akpm@linux-foundation.org: tweak comments] Link: http://lkml.kernel.org/r/20170306131408.9828-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:53:19 +0000 (14:53 -0700)]
xfs: use memalloc_nofs_{save,restore} instead of memalloc_noio*
kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore}
API to prevent from reclaim recursion into the fs because vmalloc can
invoke unconditional GFP_KERNEL allocations and these functions might be
called from the NOFS contexts. The memalloc_noio_save will enforce
GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be
unnecessary. Let's use memalloc_nofs_{save,restore} instead as it
should provide exactly what we need here - implicit GFP_NOFS context.
Link: http://lkml.kernel.org/r/20170306131408.9828-6-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:53:15 +0000 (14:53 -0700)]
mm: introduce memalloc_nofs_{save,restore} API
GFP_NOFS context is used for the following 5 reasons currently:
- to prevent from deadlocks when the lock held by the allocation
context would be needed during the memory reclaim
- to prevent from stack overflows during the reclaim because the
allocation is performed from a deep context already
- to prevent lockups when the allocation context depends on other
reclaimers to make a forward progress indirectly
- just in case because this would be safe from the fs POV
- silence lockdep false positives
Unfortunately overuse of this allocation context brings some problems to
the MM. Memory reclaim is much weaker (especially during heavy FS
metadata workloads), OOM killer cannot be invoked because the MM layer
doesn't have enough information about how much memory is freeable by the
FS layer.
In many cases it is far from clear why the weaker context is even used
and so it might be used unnecessarily. We would like to get rid of
those as much as possible. One way to do that is to use the flag in
scopes rather than isolated cases. Such a scope is declared when really
necessary, tracked per task and all the allocation requests from within
the context will simply inherit the GFP_NOFS semantic.
Not only this is easier to understand and maintain because there are
much less problematic contexts than specific allocation requests, this
also helps code paths where FS layer interacts with other layers (e.g.
crypto, security modules, MM etc...) and there is no easy way to convey
the allocation context between the layers.
Introduce memalloc_nofs_{save,restore} API to control the scope of
GFP_NOFS allocation context. This is basically copying
memalloc_noio_{save,restore} API we have for other restricted allocation
context GFP_NOIO. The PF_MEMALLOC_NOFS flag already exists and it is
just an alias for PF_FSTRANS which has been xfs specific until recently.
There are no more PF_FSTRANS users anymore so let's just drop it.
PF_MEMALLOC_NOFS is now checked in the MM layer and drops __GFP_FS
implicitly same as PF_MEMALLOC_NOIO drops __GFP_IO. memalloc_noio_flags
is renamed to current_gfp_context because it now cares about both
PF_MEMALLOC_NOFS and PF_MEMALLOC_NOIO contexts. Xfs code paths preserve
their semantic. kmem_flags_convert() doesn't need to evaluate the flag
anymore.
This patch shouldn't introduce any functional changes.
Let's hope that filesystems will drop direct GFP_NOFS (resp. ~__GFP_FS)
usage as much as possible and only use a properly documented
memalloc_nofs_{save,restore} checkpoints where they are appropriate.
[akpm@linux-foundation.org: fix comment typo, reflow comment] Link: http://lkml.kernel.org/r/20170306131408.9828-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:53:12 +0000 (14:53 -0700)]
xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS
xfs has defined PF_FSTRANS to declare a scope GFP_NOFS semantic quite
some time ago. We would like to make this concept more generic and use
it for other filesystems as well. Let's start by giving the flag a more
generic name PF_MEMALLOC_NOFS which is in line with an exiting
PF_MEMALLOC_NOIO already used for the same purpose for GFP_NOIO
contexts. Replace all PF_FSTRANS usage from the xfs code in the first
step before we introduce a full API for it as xfs uses the flag directly
anyway.
This patch doesn't introduce any functional change.
Link: http://lkml.kernel.org/r/20170306131408.9828-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Wed, 3 May 2017 21:53:09 +0000 (14:53 -0700)]
lockdep: allow to disable reclaim lockup detection
The current implementation of the reclaim lockup detection can lead to
false positives and those even happen and usually lead to tweak the code
to silence the lockdep by using GFP_NOFS even though the context can use
__GFP_FS just fine.
To quote Dave:
"Ignoring whether reflink should be doing anything or not, that's a
"xfs_refcountbt_init_cursor() gets called both outside and inside
transactions" lockdep false positive case. The problem here is lockdep
has seen this allocation from within a transaction, hence a GFP_NOFS
allocation, and now it's seeing it in a GFP_KERNEL context. Also note
that we have an active reference to this inode.
So, because the reclaim annotations overload the interrupt level
detections and it's seen the inode ilock been taken in reclaim
("interrupt") context, this triggers a reclaim context warning where
it thinks it is unsafe to do this allocation in GFP_KERNEL context
holding the inode ilock..."
This sounds like a fundamental problem of the reclaim lock detection.
It is really impossible to annotate such a special usecase IMHO unless
the reclaim lockup detection is reworked completely. Until then it is
much better to provide a way to add "I know what I am doing flag" and
mark problematic places. This would prevent from abusing GFP_NOFS flag
which has a runtime effect even on configurations which have lockdep
disabled.
Introduce __GFP_NOLOCKDEP flag which tells the lockdep gfp tracking to
skip the current allocation request.
While we are at it also make sure that the radix tree doesn't
accidentaly override tags stored in the upper part of the gfp_mask.
Link: http://lkml.kernel.org/r/20170306131408.9828-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nikolay Borisov [Wed, 3 May 2017 21:53:05 +0000 (14:53 -0700)]
lockdep: teach lockdep about memalloc_noio_save
Patch series "scope GFP_NOFS api", v5.
This patch (of 7):
Commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.
This was further extended in commit 934f3072c17c ("mm: clear __GFP_FS
when PF_MEMALLOC_NOIO is set").
memalloc_noio_* functions prevent allocation paths recursing back into
the filesystem without explicitly changing the flags for every
allocation site.
However, lockdep hasn't been keeping up with the changes and it entirely
misses handling the memalloc_noio adjustments. Instead, it is left to
the callers of __lockdep_trace_alloc to call the function after they
have shaven the respective GFP flags which can lead to false positives:
=================================
[ INFO: inconsistent lock state ]
4.10.0-nbor #134 Not tainted
---------------------------------
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&xfs_nondir_ilock_class){++++?.}, at: xfs_ilock+0x141/0x230
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x62a/0x17c0
lock_acquire+0xc5/0x220
down_write_nested+0x4f/0x90
xfs_ilock+0x141/0x230
xfs_reclaim_inode+0x12a/0x320
xfs_reclaim_inodes_ag+0x2c8/0x4e0
xfs_reclaim_inodes_nr+0x33/0x40
xfs_fs_free_cached_objects+0x19/0x20
super_cache_scan+0x191/0x1a0
shrink_slab+0x26f/0x5f0
shrink_node+0xf9/0x2f0
kswapd+0x356/0x920
kthread+0x10c/0x140
ret_from_fork+0x31/0x40
irq event stamp: 173777
hardirqs last enabled at (173777): __local_bh_enable_ip+0x70/0xc0
hardirqs last disabled at (173775): __local_bh_enable_ip+0x37/0xc0
softirqs last enabled at (173776): _xfs_buf_find+0x67a/0xb70
softirqs last disabled at (173774): _xfs_buf_find+0x5db/0xb70
other info that might help us debug this:
Possible unsafe locking scenario:
Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.
Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set") Link: http://lkml.kernel.org/r/20170306131408.9828-2-mhocko@kernel.org Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Brian Foster <bfoster@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Wed, 3 May 2017 21:52:59 +0000 (14:52 -0700)]
mm, vmstat: print non-populated zones in zoneinfo
Initscripts can use the information (protection levels) from
/proc/zoneinfo to configure vm.lowmem_reserve_ratio at boot.
vm.lowmem_reserve_ratio is an array of ratios for each configured zone
on the system. If a zone is not populated on an arch, /proc/zoneinfo
suppresses its output.
This results in there not being a 1:1 mapping between the set of zones
emitted by /proc/zoneinfo and the zones configured by
vm.lowmem_reserve_ratio.
This patch shows statistics for non-populated zones in /proc/zoneinfo.
The zones exist and hold a spot in the vm.lowmem_reserve_ratio array.
Without this patch, it is not possible to determine which index in the
array controls which zone if one or more zones on the system are not
populated.
Remaining users of walk_zones_in_node() are unchanged. Files such as
/proc/pagetypeinfo require certain zone data to be initialized properly
for display, which is not done for unpopulated zones.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1703031451310.98023@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Wed, 3 May 2017 21:52:49 +0000 (14:52 -0700)]
mm, swap: Fix a race in free_swap_and_cache()
Before using cluster lock in free_swap_and_cache(), the
swap_info_struct->lock will be held during freeing the swap entry and
acquiring page lock, so the page swap count will not change when testing
page information later. But after using cluster lock, the cluster lock
(or swap_info_struct->lock) will be held only during freeing the swap
entry. So before acquiring the page lock, the page swap count may be
changed in another thread. If the page swap count is not 0, we should
not delete the page from the swap cache. This is fixed via checking
page swap count again after acquiring the page lock.
I found the race when I review the code, so I didn't trigger the race
via a test program. If the race occurs for an anonymous page shared by
multiple processes via fork, multiple pages will be allocated and
swapped in from the swap device for the previously shared one page.
That is, the user-visible runtime effect is more memory will be used and
the access latency for the page will be higher, that is, the performance
regression.
Link: http://lkml.kernel.org/r/20170301143905.12846-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tim Chen <tim.c.chen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:45 +0000 (14:52 -0700)]
mm: memcontrol: provide shmem statistics
Cgroups currently don't report how much shmem they use, which can be
useful data to have, in particular since shmem is included in the
cache/file item while being reclaimed like anonymous memory.
Add a counter to track shmem pages during charging and uncharging.
Link: http://lkml.kernel.org/r/20170221164343.32252-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Chris Down <cdown@fb.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Wed, 3 May 2017 21:52:42 +0000 (14:52 -0700)]
proc: show MADV_FREE pages info in smaps
Show MADV_FREE pages info of each vma in smaps. The interface is for
diganose or monitoring purpose, userspace could use it to understand
what happens in the application. Since userspace could dirty MADV_FREE
pages without notice from kernel, this interface is the only place we
can get accurate accounting info about MADV_FREE pages.
[mhocko@kernel.org: update Documentation/filesystems/proc.txt] Link: http://lkml.kernel.org/r/89efde633559de1ec07444f2ef0f4963a97a2ce8.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 3 May 2017 21:52:36 +0000 (14:52 -0700)]
mm: fix lazyfree BUG_ON check in try_to_unmap_one()
If a page is swapbacked, it means it should be in swapcache in
try_to_unmap_one's path.
If a page is !swapbacked, it mean it shouldn't be in swapcache in
try_to_unmap_one's path.
Check both two cases all at once and if it fails, warn and return
SWAP_FAIL. Such bug never mean we should shut down the kernel.
[minchan@kernel.org: do not use VM_WARN_ON_ONCE as if condition[ Link: http://lkml.kernel.org/r/20170309060226.GB854@bbox Link: http://lkml.kernel.org/r/20170307055551.GC29458@bbox Signed-off-by: Minchan Kim <minchan@kernel.org> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@fb.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Wed, 3 May 2017 21:52:32 +0000 (14:52 -0700)]
mm: reclaim MADV_FREE pages
When memory pressure is high, we free MADV_FREE pages. If the pages are
not dirty in pte, the pages could be freed immediately. Otherwise we
can't reclaim them. We put the pages back to anonumous LRU list (by
setting SwapBacked flag) and the pages will be reclaimed in normal
swapout way.
We use normal page reclaim policy. Since MADV_FREE pages are put into
inactive file list, such pages and inactive file pages are reclaimed
according to their age. This is expected, because we don't want to
reclaim too many MADV_FREE pages before used once pages.
Based on Minchan's original patch
[minchan@kernel.org: clean up lazyfree page handling] Link: http://lkml.kernel.org/r/20170303025237.GB3503@bbox Link: http://lkml.kernel.org/r/14b8eb1d3f6bf6cc492833f183ac8c304e560484.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Wed, 3 May 2017 21:52:29 +0000 (14:52 -0700)]
mm: move MADV_FREE pages into LRU_INACTIVE_FILE list
madv()'s MADV_FREE indicate pages are 'lazyfree'. They are still
anonymous pages, but they can be freed without pageout. To distinguish
these from normal anonymous pages, we clear their SwapBacked flag.
MADV_FREE pages could be freed without pageout, so they pretty much like
used once file pages. For such pages, we'd like to reclaim them once
there is memory pressure. Also it might be unfair reclaiming MADV_FREE
pages always before used once file pages and we definitively want to
reclaim the pages before other anonymous and file pages.
To speed up MADV_FREE pages reclaim, we put the pages into
LRU_INACTIVE_FILE list. The rationale is LRU_INACTIVE_FILE list is tiny
nowadays and should be full of used once file pages. Reclaiming
MADV_FREE pages will not have much interfere of anonymous and active
file pages. And the inactive file pages and MADV_FREE pages will be
reclaimed according to their age, so we don't reclaim too many MADV_FREE
pages too. Putting the MADV_FREE pages into LRU_INACTIVE_FILE_LIST also
means we can reclaim the pages without swap support. This idea is
suggested by Johannes.
This patch doesn't move MADV_FREE pages to LRU_INACTIVE_FILE list yet to
avoid bisect failure, next patch will do it.
The patch is based on Minchan's original patch.
[akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/2f87063c1e9354677b7618c647abde77b07561e5.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Wed, 3 May 2017 21:52:26 +0000 (14:52 -0700)]
mm: don't assume anonymous pages have SwapBacked flag
There are a few places the code assumes anonymous pages should have
SwapBacked flag set. MADV_FREE pages are anonymous pages but we are
going to add them to LRU_INACTIVE_FILE list and clear SwapBacked flag
for them. The assumption doesn't hold any more, so fix them.
Link: http://lkml.kernel.org/r/3945232c0df3dd6c4ef001976f35a95f18dcb407.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Wed, 3 May 2017 21:52:22 +0000 (14:52 -0700)]
mm: delete unnecessary TTU_* flags
Patch series "mm: fix some MADV_FREE issues", v5.
We are trying to use MADV_FREE in jemalloc. Several issues are found.
Without solving the issues, jemalloc can't use the MADV_FREE feature.
- Doesn't support system without swap enabled. Because if swap is off,
we can't or can't efficiently age anonymous pages. And since
MADV_FREE pages are mixed with other anonymous pages, we can't
reclaim MADV_FREE pages. In current implementation, MADV_FREE will
fallback to MADV_DONTNEED without swap enabled. But in our
environment, a lot of machines don't enable swap. This will prevent
our setup using MADV_FREE.
- Increases memory pressure. page reclaim bias file pages reclaim
against anonymous pages. This doesn't make sense for MADV_FREE pages,
because those pages could be freed easily and refilled with very
slight penality. Even page reclaim doesn't bias file pages, there is
still an issue, because MADV_FREE pages and other anonymous pages are
mixed together. To reclaim a MADV_FREE page, we probably must scan a
lot of other anonymous pages, which is inefficient. In our test, we
usually see oom with MADV_FREE enabled and nothing without it.
- Accounting. There are two accounting problems. We don't have a global
accounting. If the system is abnormal, we don't know if it's a
problem from MADV_FREE side. The other problem is RSS accounting.
MADV_FREE pages are accounted as normal anon pages and reclaimed
lazily, so application's RSS becomes bigger. This confuses our
workloads. We have monitoring daemon running and if it finds
applications' RSS becomes abnormal, the daemon will kill the
applications even kernel can reclaim the memory easily.
To address the first the two issues, we can either put MADV_FREE pages
into a separate LRU list (Minchan's previous patches and V1 patches), or
put them into LRU_INACTIVE_FILE list (suggested by Johannes). The
patchset use the second idea. The reason is LRU_INACTIVE_FILE list is
tiny nowadays and should be full of used once file pages. So we can
still efficiently reclaim MADV_FREE pages there without interference
with other anon and active file pages. Putting the pages into inactive
file list also has an advantage which allows page reclaim to prioritize
MADV_FREE pages and used once file pages. MADV_FREE pages are put into
the lru list and clear SwapBacked flag, so PageAnon(page) &&
!PageSwapBacked(page) will indicate a MADV_FREE pages. These pages will
directly freed without pageout if they are clean, otherwise normal swap
will reclaim them.
For the third issue, the previous post adds global accounting and a
separate RSS count for MADV_FREE pages. The problem is we never get
accurate accounting for MADV_FREE pages. The pages are mapped to
userspace, can be dirtied without notice from kernel side. To get
accurate accounting, we could write protect the page, but then there is
extra page fault overhead, which people don't want to pay. Jemalloc
guys have concerns about the inaccurate accounting, so this post drops
the accounting patches temporarily. The info exported to
/proc/pid/smaps for MADV_FREE pages are kept, which is the only place we
can get accurate accounting right now.
This patch (of 6):
Johannes pointed out TTU_LZFREE is unnecessary. It's true because we
always have the flag set if we want to do an unmap. For cases we don't
do an unmap, the TTU_LZFREE part of code should never run.
Also the TTU_UNMAP is unnecessary. If no other flags set (for example,
TTU_MIGRATION), an unmap is implied.
The patch includes Johannes's cleanup and dead TTU_ACTION macro removal
code
Link: http://lkml.kernel.org/r/4be3ea1bc56b26fd98a54d0a6f70bec63f6d8980.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:16 +0000 (14:52 -0700)]
mm: remove unnecessary back-off function when retrying page reclaim
The backoff mechanism is not needed. If we have MAX_RECLAIM_RETRIES
loops without progress, we'll OOM anyway; backing off might cut one or
two iterations off that in the rare OOM case. If we have intermittent
success reclaiming a few pages, the backoff function gets reset also,
and so is of little help in these scenarios.
We might want a backoff function for when there IS progress, but not
enough to be satisfactory. But this isn't that. Remove it.
Link: http://lkml.kernel.org/r/20170228214007.5621-10-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that reclaimability of a node is no longer based on the ratio
between pages scanned and theoretically reclaimable pages, we can remove
accounting tricks for pages skipped due to zone constraints.
Link: http://lkml.kernel.org/r/20170228214007.5621-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:10 +0000 (14:52 -0700)]
mm: delete NR_PAGES_SCANNED and pgdat_reclaimable()
NR_PAGES_SCANNED counts number of pages scanned since the last page free
event in the allocator. This was used primarily to measure the
reclaimability of zones and nodes, and determine when reclaim should
give up on them. In that role, it has been replaced in the preceding
patches by a different mechanism.
Being implemented as an efficient vmstat counter, it was automatically
exported to userspace as well. It's however unlikely that anyone
outside the kernel is using this counter in any meaningful way.
Remove the counter and the unused pgdat_reclaimable().
Link: http://lkml.kernel.org/r/20170228214007.5621-8-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:07 +0000 (14:52 -0700)]
mm: don't avoid high-priority reclaim on memcg limit reclaim
Commit 246e87a93934 ("memcg: fix get_scan_count() for small targets")
sought to avoid high reclaim priorities for memcg by forcing it to scan
a minimum amount of pages when lru_pages >> priority yielded nothing.
This was done at a time when reclaim decisions like dirty throttling
were tied to the priority level.
Nowadays, the only meaningful thing still tied to priority dropping
below DEF_PRIORITY - 2 is gating whether laptop_mode=1 is generally
allowed to write. But that is from an era where direct reclaim was
still allowed to call ->writepage, and kswapd nowadays avoids writes
until it's scanned every clean page in the system. Potential changes to
how quick sc->may_writepage could trigger are of little concern.
Remove the force_scan stuff, as well as the ugly multi-pass target
calculation that it necessitated.
Link: http://lkml.kernel.org/r/20170228214007.5621-7-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:03 +0000 (14:52 -0700)]
mm: don't avoid high-priority reclaim on unreclaimable nodes
Commit 246e87a93934 ("memcg: fix get_scan_count() for small targets")
sought to avoid high reclaim priorities for kswapd by forcing it to scan
a minimum amount of pages when lru_pages >> priority yielded nothing.
Commit b95a2f2d486d ("mm: vmscan: convert global reclaim to per-memcg
LRU lists"), due to switching global reclaim to a round-robin scheme
over all cgroups, had to restrict this forceful behavior to
unreclaimable zones in order to prevent massive overreclaim with many
cgroups.
The latter patch effectively neutered the behavior completely for all
but extreme memory pressure. But in those situations we might as well
drop the reclaimers to lower priority levels. Remove the check.
Link: http://lkml.kernel.org/r/20170228214007.5621-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:52:00 +0000 (14:52 -0700)]
mm: remove unnecessary reclaimability check from NUMA balancing target
NUMA balancing already checks the watermarks of the target node to
decide whether it's a suitable balancing target. Whether the node is
reclaimable or not is irrelevant when we don't intend to reclaim.
Link: http://lkml.kernel.org/r/20170228214007.5621-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:51:57 +0000 (14:51 -0700)]
mm: remove seemingly spurious reclaimability check from laptop_mode gating
Commit 1d82de618ddd ("mm, vmscan: make kswapd reclaim in terms of
nodes") allowed laptop_mode=1 to start writing not just when the
priority drops to DEF_PRIORITY - 2 but also when the node is
unreclaimable.
That appears to be a spurious change in this patch as I doubt the series
was tested with laptop_mode, and neither is that particular change
mentioned in the changelog. Remove it, it's still recent.
Link: http://lkml.kernel.org/r/20170228214007.5621-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:51:54 +0000 (14:51 -0700)]
mm: fix check for reclaimable pages in PF_MEMALLOC reclaim throttling
PF_MEMALLOC direct reclaimers get throttled on a node when the sum of
all free pages in each zone fall below half the min watermark. During
the summation, we want to exclude zones that don't have reclaimables.
Checking the same pgdat over and over again doesn't make sense.
Fixes: 599d0c954f91 ("mm, vmscan: move LRU lists to node") Link: http://lkml.kernel.org/r/20170228214007.5621-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jia He <hejianet@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Wed, 3 May 2017 21:51:51 +0000 (14:51 -0700)]
mm: fix 100% CPU kswapd busyloop on unreclaimable nodes
Patch series "mm: kswapd spinning on unreclaimable nodes - fixes and
cleanups".
Jia reported a scenario in which the kswapd of a node indefinitely spins
at 100% CPU usage. We have seen similar cases at Facebook.
The kernel's current method of judging its ability to reclaim a node (or
whether to back off and sleep) is based on the amount of scanned pages
in proportion to the amount of reclaimable pages. In Jia's and our
scenarios, there are no reclaimable pages in the node, however, and the
condition for backing off is never met. Kswapd busyloops in an attempt
to restore the watermarks while having nothing to work with.
This series reworks the definition of an unreclaimable node based not on
scanning but on whether kswapd is able to actually reclaim pages in
MAX_RECLAIM_RETRIES (16) consecutive runs. This is the same criteria
the page allocator uses for giving up on direct reclaim and invoking the
OOM killer. If it cannot free any pages, kswapd will go to sleep and
leave further attempts to direct reclaim invocations, which will either
make progress and re-enable kswapd, or invoke the OOM killer.
Patch #1 fixes the immediate problem Jia reported, the remainder are
smaller fixlets, cleanups, and overall phasing out of the old method.
Patch #6 is the odd one out. It's a nice cleanup to get_scan_count(),
and directly related to #5, but in itself not relevant to the series.
If the whole series is too ambitious for 4.11, I would consider the
first three patches fixes, the rest cleanups.
This patch (of 9):
Jia He reports a problem with kswapd spinning at 100% CPU when
requesting more hugepages than memory available in the system:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
76 root 20 0 0 0 0 R 100.0 0.000 217:17.29 kswapd3
At that time, there are no reclaimable pages left in the node, but as
kswapd fails to restore the high watermarks it refuses to go to sleep.
Kswapd needs to back away from nodes that fail to balance. Up until
commit 1d82de618ddd ("mm, vmscan: make kswapd reclaim in terms of
nodes") kswapd had such a mechanism. It considered zones whose
theoretically reclaimable pages it had reclaimed six times over as
unreclaimable and backed away from them. This guard was erroneously
removed as the patch changed the definition of a balanced node.
However, simply restoring this code wouldn't help in the case reported
here: there *are* no reclaimable pages that could be scanned until the
threshold is met. Kswapd would stay awake anyway.
Introduce a new and much simpler way of backing off. If kswapd runs
through MAX_RECLAIM_RETRIES (16) cycles without reclaiming a single
page, make it back off from the node. This is the same number of shots
direct reclaim takes before declaring OOM. Kswapd will go to sleep on
that node until a direct reclaimer manages to reclaim some pages, thus
proving the node reclaimable again.
[hannes@cmpxchg.org: check kswapd failure against the cumulative nr_reclaimed count] Link: http://lkml.kernel.org/r/20170306162410.GB2090@cmpxchg.org
[shakeelb@google.com: fix condition for throttle_direct_reclaim] Link: http://lkml.kernel.org/r/20170314183228.20152-1-shakeelb@google.com Link: http://lkml.kernel.org/r/20170228214007.5621-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Shakeel Butt <shakeelb@google.com> Reported-by: Jia He <hejianet@gmail.com> Tested-by: Jia He <hejianet@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg Thelen [Wed, 3 May 2017 21:51:47 +0000 (14:51 -0700)]
slab: avoid IPIs when creating kmem caches
Each slab kmem cache has per cpu array caches. The array caches are
created when the kmem_cache is created, either via kmem_cache_create()
or lazily when the first object is allocated in context of a kmem
enabled memcg. Array caches are replaced by writing to /proc/slabinfo.
Array caches are protected by holding slab_mutex or disabling
interrupts. Array cache allocation and replacement is done by
__do_tune_cpucache() which holds slab_mutex and calls
kick_all_cpus_sync() to interrupt all remote processors which confirms
there are no references to the old array caches.
IPIs are needed when replacing array caches. But when creating a new
array cache, there's no need to send IPIs because there cannot be any
references to the new cache. Outside of memcg kmem accounting these
IPIs occur at boot time, so they're not a problem. But with memcg kmem
accounting each container can create kmem caches, so the IPIs are
wasteful.
Avoid unnecessary IPIs when creating array caches.
Test which reports the IPI count of allocating slab in 10000 memcg:
import os
def ipi_count():
with open("/proc/interrupts") as f:
for l in f:
if 'Function call interrupts' in l:
return int(l.split()[1])
def echo(val, path):
with open(path, "w") as f:
f.write(val)
n = 10000
os.chdir("/mnt/cgroup/memory")
pid = str(os.getpid())
a = ipi_count()
for i in range(n):
os.mkdir(str(i))
echo("1G\n", "%d/memory.limit_in_bytes" % i)
echo("1G\n", "%d/memory.kmem.limit_in_bytes" % i)
echo(pid, "%d/cgroup.procs" % i)
open("/tmp/x", "w").close()
os.unlink("/tmp/x")
b = ipi_count()
print "%d loops: %d => %d (+%d ipis)" % (n, a, b, b-a)
echo(pid, "cgroup.procs")
for i in range(n):
os.rmdir(str(i))
Junxiao Bi [Wed, 3 May 2017 21:51:41 +0000 (14:51 -0700)]
ocfs2: o2hb: revert hb threshold to keep compatible
Configfs is the interface for ocfs2-tools to set configure to kernel and
$configfs_dir/cluster/$clustername/heartbeat/dead_threshold is the one
used to configure heartbeat dead threshold. Kernel has a default value
of it but user can set O2CB_HEARTBEAT_THRESHOLD in /etc/sysconfig/o2cb
to override it.
Commit 45b997737a80 ("ocfs2/cluster: use per-attribute show and store
methods") changed heartbeat dead threshold name while ocfs2-tools did
not, so ocfs2-tools won't set this configurable and the default value is
always used. So revert it.
Fixes: 45b997737a80 ("ocfs2/cluster: use per-attribute show and store methods") Link: http://lkml.kernel.org/r/1490665245-15374-1-git-send-email-junxiao.bi@oracle.com Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Acked-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Ian King [Wed, 3 May 2017 21:51:32 +0000 (14:51 -0700)]
scripts/spelling.txt: add several more common spelling mistakes
Here are some of the more common spelling mistakes that I've found while
fixing up spelling mistakes in kernel error message text. They probably
should be added to this list so we don't keep on seeing them appearing
again.
Link: http://lkml.kernel.org/r/20170421122534.5378-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Joe Perches <joe@perches.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pankaj Gupta [Wed, 3 May 2017 21:51:28 +0000 (14:51 -0700)]
lib/dma-debug.c: make locking work for RT
Interrupt enable/disabled with spinlock is not a valid operation for RT
as it can make executing tasks sleep from a non-sleepable context. So
convert it to spin_lock_irq[save, restore].
Linus Torvalds [Wed, 3 May 2017 16:21:59 +0000 (09:21 -0700)]
Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
"Fourteen audit patches for v4.12 that span the full range of fixes,
new features, and internal cleanups.
We have a patches to move to 64-bit timestamps, convert refcounts from
atomic_t to refcount_t, track PIDs using the pid struct instead of
pid_t, convert our own private audit buffer cache to a standard
kmem_cache, log kernel module names when they are unloaded, and
normalize the NETFILTER_PKT to make the userspace folks happier.
From a fixes perspective, the most important is likely the auditd
connection tracking RCU fix; it was a rather brain dead bug that I'll
take the blame for, but thankfully it didn't seem to affect many
people (only one report).
I think the patch subject lines and commit descriptions do a pretty
good job of explaining the details and why the changes are important
so I'll point you there instead of duplicating it here; as usual, if
you have any questions you know where to find us.
We also manage to take out more code than we put in this time, that
always makes me happy :)"
* 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit:
audit: fix the RCU locking for the auditd_connection structure
audit: use kmem_cache to manage the audit_buffer cache
audit: Use timespec64 to represent audit timestamps
audit: store the auditd PID as a pid struct instead of pid_t
audit: kernel generated netlink traffic should have a portid of 0
audit: combine audit_receive() and audit_receive_skb()
audit: convert audit_watch.count from atomic_t to refcount_t
audit: convert audit_tree.count from atomic_t to refcount_t
audit: normalize NETFILTER_PKT
netfilter: use consistent ipv4 network offset in xt_AUDIT
audit: log module name on delete_module
audit: remove unnecessary semicolon in audit_watch_handle_event()
audit: remove unnecessary semicolon in audit_mark_handle_event()
audit: remove unnecessary semicolon in audit_field_valid()
Linus Torvalds [Wed, 3 May 2017 15:50:52 +0000 (08:50 -0700)]
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"Highlights:
IMA:
- provide ">" and "<" operators for fowner/uid/euid rules
KEYS:
- add a system blacklist keyring
- add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction
functionality to userland via keyctl()
LSM:
- harden LSM API with __ro_after_init
- add prlmit security hook, implement for SELinux
- revive security_task_alloc hook
TPM:
- implement contextual TPM command 'spaces'"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits)
tpm: Fix reference count to main device
tpm_tis: convert to using locality callbacks
tpm: fix handling of the TPM 2.0 event logs
tpm_crb: remove a cruft constant
keys: select CONFIG_CRYPTO when selecting DH / KDF
apparmor: Make path_max parameter readonly
apparmor: fix parameters so that the permission test is bypassed at boot
apparmor: fix invalid reference to index variable of iterator line 836
apparmor: use SHASH_DESC_ON_STACK
security/apparmor/lsm.c: set debug messages
apparmor: fix boolreturn.cocci warnings
Smack: Use GFP_KERNEL for smk_netlbl_mls().
smack: fix double free in smack_parse_opts_str()
KEYS: add SP800-56A KDF support for DH
KEYS: Keyring asymmetric key restrict method with chaining
KEYS: Restrict asymmetric key linkage using a specific keychain
KEYS: Add a lookup_restriction function for the asymmetric key type
KEYS: Add KEYCTL_RESTRICT_KEYRING
KEYS: Consistent ordering for __key_link_begin and restrict check
KEYS: Add an optional lookup_restriction hook to key_type
...
Linus Torvalds [Wed, 3 May 2017 01:24:16 +0000 (18:24 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatch updates from Jiri Kosina:
- a per-task consistency model is being added for architectures that
support reliable stack dumping (extending this, currently rather
trivial set, is currently in the works).
This extends the nature of the types of patches that can be applied
by live patching infrastructure. The code stems from the design
proposal made [1] back in November 2014. It's a hybrid of SUSE's
kGraft and RH's kpatch, combining advantages of both: it uses
kGraft's per-task consistency and syscall barrier switching combined
with kpatch's stack trace switching. There are also a number of
fallback options which make it quite flexible.
Most of the heavy lifting done by Josh Poimboeuf with help from
Miroslav Benes and Petr Mladek
- module load time patch optimization from Zhou Chengming
- a few assorted small fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: add missing printk newlines
livepatch: Cancel transition a safe way for immediate patches
livepatch: Reduce the time of finding module symbols
livepatch: make klp_mutex proper part of API
livepatch: allow removal of a disabled patch
livepatch: add /proc/<pid>/patch_state
livepatch: change to a per-task consistency model
livepatch: store function sizes
livepatch: use kstrtobool() in enabled_store()
livepatch: move patching functions into patch.c
livepatch: remove unnecessary object loaded check
livepatch: separate enabled and patched states
livepatch/s390: add TIF_PATCH_PENDING thread flag
livepatch/s390: reorganize TIF thread flag bits
livepatch/powerpc: add TIF_PATCH_PENDING thread flag
livepatch/x86: add TIF_PATCH_PENDING thread flag
livepatch: create temporary klp_update_patch_state() stub
x86/entry: define _TIF_ALLWORK_MASK flags explicitly
stacktrace/x86: add function for detecting reliable stack traces
Linus Torvalds [Wed, 3 May 2017 01:07:04 +0000 (18:07 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID subsystem updates from Jiri Kosina:
- The need for HID_QUIRK_NO_INIT_REPORTS per-device quirk has been
growing dramatically during past years, so the time has come to
switch over the default, and perform the pro-active reading only in
cases where it's really needed (multitouch, wacom).
The only place where this behavior is (in some form) preserved is
hiddev so that we don't introduce userspace-visible change of
behavior.
From Benjamin Tissoires
- HID++ support for power_supply / baterry reporting.
From Benjamin Tissoires and Bastien Nocera
- Vast improvements / rework of DS3 and DS4 in Sony driver.
From Roderick Colenbrander
- Improvment (in terms of getting closer to the Microsoft's
interpretation of slightly ambiguous specification) of logical range
interpretation in case null-state is set in the rdesc.
From Valtteri Heikkilä and Tomasz Kramkowski
- A lot of newly supported device IDs and small assorted fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (71 commits)
HID: usbhid: Add HID_QUIRK_NOGET for Aten CS-1758 KVM switch
HID: asus: support backlight on USB keyboards
HID: wacom: Move wacom_remote_irq and wacom_remote_status_irq
HID: wacom: generic: sync pad events only for actual packets
HID: sony: remove redundant check for -ve err
HID: sony: Make sure to unregister sensors on failure
HID: sony: Make DS4 bt poll interval adjustable
HID: sony: Set proper bit flags on DS4 output report
HID: sony: DS4 use brighter LED colors
HID: sony: Improve navigation controller axis/button mapping
HID: sony: Use DS3 MAC address as unique identifier on USB
HID: logitech-hidpp: add a sysfs file to tell we support power_supply
HID: logitech-hidpp: enable HID++ 1.0 battery reporting
HID: logitech-hidpp: add support for battery status for the K750
HID: logitech-hidpp: battery: provide CAPACITY_LEVEL
HID: logitech-hidpp: rename battery level into capacity
HID: logitech-hidpp: battery: provide ONLINE property
HID: logitech-hidpp: notify battery on connect
HID: logitech-hidpp: return an error if the queried feature is not present
HID: logitech-hidpp: create the battery for all types of HID++ devices
...
Linus Torvalds [Wed, 3 May 2017 00:59:33 +0000 (17:59 -0700)]
Merge tag 'pinctrl-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control updates from Linus Walleij:
"This is the bulk of pin control changes for the v4.12 cycle.
The extra week before the merge window actually resulted in some of
the type of fixes that usually arrive after the merge window already
starting to trickle in from eager developers using -next, I'm
impressed.
I have recruited a Samsung subsubsystem maintainer (Krzysztof) to deal
with the onset of Samsung patches. It works great.
Apart from that it is a boring round, just incremental updates and
fixes all over the place, no serious core changes or anything exciting
like that. The most pleasing to see is Julia Cartwrights work to audit
the irqchip-providing drivers for realtime locking compliance. It's
one of those "I should really get around to looking into that" things
that have been on my TODO list since forever.
Summary:
Core changes:
- add bi-directional and output-enable pin configurations to the
generic bindings and generic pin controlling core.
New drivers or subdrivers:
- Armada 37xx SoC pin controller and GPIO support.
- Axis ARTPEC-6 SoC pin controller support.
- AllWinner A64 R_PIO controller support, and opening up the
AllWinner sunxi driver for ARM64 use.
- Rockchip RK3328 support.
- Renesas R-Car H3 ES2.0 support.
- STM32F469 support in the STM32 driver.
- Aspeed G4 and G5 pin controller support.
Improvements:
- a whole slew of realtime improvements to drivers implementing
irqchips: BCM, AMD, SiRF, sunxi, rockchip.
- switch meson driver to get the GPIO ranges from the device tree.
- input schmitt trigger support on the Rockchip driver.
- enable the sunxi (AllWinner) driver to also be used on ARM64
silicon.
- name the Qualcomm QDF2xxx GPIO lines.
- support GMMR GPIO regions on the Intel Cherryview. This fixes a
serialization problem on these platforms.
- pad retention support for the Samsung Exynos 5433.
- handle suspend-to-ram in the AT91-pio4 driver.
- pin configuration support in the Aspeed driver.
Cleanups:
- the final name of Rockchip RK1108 was RV1108 so rename the driver
and variables to stay consistent"
* tag 'pinctrl-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (80 commits)
pinctrl: mediatek: Add missing pinctrl bindings for mt7623
pinctrl: artpec6: Fix return value check in artpec6_pmx_probe()
pinctrl: artpec6: Remove .owner field for driver
pinctrl: tegra: xusb: Silence sparse warnings
ARM: at91/at91-pinctrl documentation: fix spelling mistake: "contoller" -> "controller"
pinctrl: make artpec6 explicitly non-modular
pinctrl: aspeed: g5: Add pinconf support
pinctrl: aspeed: g4: Add pinconf support
pinctrl: aspeed: Add core pinconf support
pinctrl: aspeed: Document pinconf in devicetree bindings
pinctrl: Add st,stm32f469-pinctrl compatible to stm32-pinctrl
pinctrl: stm32: Add STM32F469 MCU support
Documentation: dt: Remove ngpios from stm32-pinctrl binding
pinctrl: stm32: replace device_initcall() with arch_initcall()
pinctrl: stm32: add possibility to use gpio-ranges to declare bank range
pinctrl: armada-37xx: Add gpio support
pinctrl: armada-37xx: Add pin controller support for Armada 37xx
pinctrl: dt-bindings: Add documentation for Armada 37xx pin controllers
pinctrl: core: Make pinctrl_init_controller() static
pinctrl: generic: Add bi-directional and output-enable
...
Linus Torvalds [Wed, 3 May 2017 00:34:32 +0000 (17:34 -0700)]
Merge tag 'mmc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
Pull MMC updates from Ulf Hansson:
"MMC core:
- Continue to re-factor code to prepare for eMMC CMDQ and blkmq support
- Introduce queue semantics to prepare for eMMC CMDQ and blkmq support
- Add helper functions to manage temporary enable/disable of eMMC CMDQ
- Improve wait-busy detection for SDIO
MMC host:
- cavium: Add driver to support Cavium controllers
- cavium: Extend Cavium driver to support Octeon and ThunderX SOCs
- bcm2835: Add new driver for Broadcom BCM2835 controller
- sdhci-xenon: Add driver to support Marvell Xenon SDHCI controller
- sdhci-tegra: Add support for the Tegra186 variant
- sdhci-of-esdhc: Support for UHS-I SD cards
- sdhci-of-esdhc: Support for eMMC HS200 cards
- sdhci-cadence: Add eMMC HS400 enhanced strobe support
- sdhci-esdhc-imx: Reset tuning circuit when needed
- sdhci-pci: Modernize and clean-up some PM related code
- sdhci-pci: Avoid re-tuning at runtime PM for some Intel devices
- sdhci-pci|acpi: Use aggressive PM for some Intel BYT controllers
- sdhci: Re-factoring and modernizations
- sdhci: Optimize delay loops
- sdhci: Improve register dump print format
- sdhci: Add support for the Command Queue Engine
- meson-gx: Various improvements and clean-ups
- meson-gx: Add support for CMD23
- meson-gx: Basic tuning support to avoid CRC errors
- s3cmci: Enable probing via DT
- mediatek: Improve tuning support for eMMC HS200 and HS400 mode
- tmio: Improve DMA support
- tmio: Use correct response for CMD12
- dw_mmc: Minor improvements and clean-ups"
* tag 'mmc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (148 commits)
mmc: sdhci-of-esdhc: limit SD clock for ls1012a/ls1046a
mmc: sdhci-of-esdhc: poll ESDHC_CLOCK_STABLE bit with udelay
mmc: sdhci-xenon: Fix default value of LOGIC_TIMING_ADJUST for eMMC5.0 PHY
mmc: sdhci-xenon: Fix the work flow in xenon_remove().
MIPS: Octeon: cavium_octeon_defconfig: Enable Octeon MMC
mmc: sdhci-xenon: Remove redundant dev_err call in get_dt_pad_ctrl_data()
mmc: cavium: Use module_pci_driver to simplify the code
mmc: cavium: Add MMC support for Octeon SOCs.
mmc: cavium: Fix detection of block or byte addressing.
mmc: core: Export API to allow hosts to get the card address
mmc: sdio: Fix sdio wait busy implement limitation
mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card
clk: apn806: fix spelling mistake: "mising" -> "missing"
mmc: sdhci-of-esdhc: add delay between tuning cycles
mmc: sdhci: Control the delay between tuning commands
mmc: sdhci-of-esdhc: add tuning support
mmc: sdhci-of-esdhc: add support for signal voltage switch
mmc: sdhci-of-esdhc: add peripheral clock support
mmc: sdhci-pci: Allow for 3 bytes from Intel DSM
mmc: cavium: Fix a shift wrapping bug
...
Pull networking updates from David Millar:
"Here are some highlights from the 2065 networking commits that
happened this development cycle:
1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri)
2) Add a generic XDP driver, so that anyone can test XDP even if they
lack a networking device whose driver has explicit XDP support
(me).
3) Sparc64 now has an eBPF JIT too (me)
4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei
Starovoitov)
5) Make netfitler network namespace teardown less expensive (Florian
Westphal)
6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana)
7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger)
8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky)
9) Multiqueue support in stmmac driver (Joao Pinto)
10) Remove TCP timewait recycling, it never really could possibly work
well in the real world and timestamp randomization really zaps any
hint of usability this feature had (Soheil Hassas Yeganeh)
11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay
Aleksandrov)
12) Add socket busy poll support to epoll (Sridhar Samudrala)
13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso,
and several others)
Linus Torvalds [Tue, 2 May 2017 22:53:46 +0000 (15:53 -0700)]
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
"Here is the crypto update for 4.12:
API:
- Add batch registration for acomp/scomp
- Change acomp testing to non-unique compressed result
- Extend algorithm name limit to 128 bytes
- Require setkey before accept(2) in algif_aead
Algorithms:
- Add support for deflate rfc1950 (zlib)
Drivers:
- Add accelerated crct10dif for powerpc
- Add crc32 in stm32
- Add sha384/sha512 in ccp
- Add 3des/gcm(aes) for v5 devices in ccp
- Add Queue Interface (QI) backend support in caam
- Add new Exynos RNG driver
- Add ThunderX ZIP driver
- Add driver for hardware random generator on MT7623 SoC"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (101 commits)
crypto: stm32 - Fix OF module alias information
crypto: algif_aead - Require setkey before accept(2)
crypto: scomp - add support for deflate rfc1950 (zlib)
crypto: scomp - allow registration of multiple scomps
crypto: ccp - Change ISR handler method for a v5 CCP
crypto: ccp - Change ISR handler method for a v3 CCP
crypto: crypto4xx - rename ce_ring_contol to ce_ring_control
crypto: testmgr - Allow ecb(cipher_null) in FIPS mode
Revert "crypto: arm64/sha - Add constant operand modifier to ASM_EXPORT"
crypto: ccp - Disable interrupts early on unload
crypto: ccp - Use only the relevant interrupt bits
hwrng: mtk - Add driver for hardware random generator on MT7623 SoC
dt-bindings: hwrng: Add Mediatek hardware random generator bindings
crypto: crct10dif-vpmsum - Fix missing preempt_disable()
crypto: testmgr - replace compression known answer test
crypto: acomp - allow registration of multiple acomps
hwrng: n2 - Use devm_kcalloc() in n2rng_probe()
crypto: chcr - Fix error handling related to 'chcr_alloc_shash'
padata: get_next is never NULL
crypto: exynos - Add new Exynos RNG driver
...
Jon Paul Maloy [Tue, 2 May 2017 16:16:54 +0000 (18:16 +0200)]
tipc: refactor function tipc_sk_recv_stream()
We try to make this function more readable by improving variable names
and comments, using more stack variables, and doing some smaller changes
to the logics. We also rename the function to make it consistent with
naming conventions used elsewhere in the code.
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jon Paul Maloy [Tue, 2 May 2017 16:16:53 +0000 (18:16 +0200)]
tipc: refactor function tipc_sk_recvmsg()
We try to make this function more readable by improving variable names
and comments, plus some minor changes to the logics.
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Tue, 2 May 2017 19:41:23 +0000 (15:41 -0400)]
Merge branch 'thunderx-xdp'
Sunil Goutham says:
====================
net: thunderx: Adds XDP support
This patch series adds support for XDP to ThunderX NIC driver
which is used on CN88xx, CN81xx and CN83xx platforms.
Patches 1-4 are performance improvement and cleanup patches
which are done keeping XDP performance bottlenecks in view.
Rest of the patches adds actual XDP support.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:58 +0000 (18:36 +0530)]
net: thunderx: Optimize page recycling for XDP
Driver follows a method of taking one extra reference on the
page for recycling which is fine in usual packet path where
each 64KB page is segmented into multiple receive buffers.
But in XDP mode since there is just one receive buffer per
page taking extra page reference itself becomes big bottleneck
consuming ~50% of CPU cycles due to atomic operations.
This patch adds a internal ref count in pgcache for each
page and additional page references are taken in a batch
instead of just one at a time. Internal i.e 'pgcache->ref_count'
and page's i.e 'page->_refcount' counters are compared to check
page's recyclability.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:57 +0000 (18:36 +0530)]
net: thunderx: Support for XDP header adjustment
When in XDP mode reserve XDP_PACKET_HEADROOM bytes at the start
of receive buffer for XDP program to modify headers and adjust
packet start. Additional code changes done to handle such packets.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:56 +0000 (18:36 +0530)]
net: thunderx: Add support for XDP_TX
Adds support for XDP_TX i.e transmits packet out of
the XDP TX queue mapped to the corresponding Rx queue
on which packet is received.
Since SQ for XDP TX will be used only on a single cpu i.e
SQ description creation and freeing, using atomic free count
is not necessary and will become a bottleneck. Hence added
a separate 'xdp_free_cnt' used for SQs designated for XDP
to track descriptor free count.
Changes also include
- A new entry 'xdp_page' is added to save transmitted packet's
page pointer for later cleanup.
- XDP Tx SQ's doorbell is ringed once per NAPI instance.
- Retrieving designated SQ for packets being sent out by stack
via 'nicvf_xmit'.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:55 +0000 (18:36 +0530)]
net: thunderx: Add support for XDP_DROP
Adds support for XDP_DROP.
Also since in XDP mode there is just a single buffer per page,
made changes to recycle DMA mapping info as well along with pages.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:54 +0000 (18:36 +0530)]
net: thunderx: Add basic XDP support
Adds basic XDP support i.e attaching a BPF program to an
interface. Also takes care of allocating separate Tx queues
for XDP path and for network stack packet transmission.
This patch doesn't support handling of any of the XDP actions,
all are treated as XDP_PASS i.e packets will be handed over to
the network stack.
Changes also involve allocating one receive buffer per page in XDP
mode and multiple in normal mode i.e when no BPF program is attached.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:52 +0000 (18:36 +0530)]
net: thunderx: Optimize CQE_TX handling
Optimized CQE handling with below changes
- Feeing descriptors back to SQ in bulk i.e once per NAPI
instance instead for every CQE_TX, this will reduce number
of atomic updates to 'sq->free_cnt'.
- Checking errors in CQE_TX and CQE_RX before calling appropriate
fn()s to update error stats i.e reduce branching.
Also removed debug messages in packet handling path which otherwise
causes issues if DEBUG is enabled.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:51 +0000 (18:36 +0530)]
net: thunderx: Optimize RBDR descriptor handling
Receive buffer's physical address or iova will anyway not
go beyond 49bits, since it is the max supported HW address.
As per perf, updating bitfields i.e buf_addr:42 in RBDR
descriptor entry consumes lots of cpu cycles, hence changed
it to a 64bit field with alignment requirements taken care of.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sunil Goutham [Tue, 2 May 2017 13:06:50 +0000 (18:36 +0530)]
net: thunderx: Support for page recycling
Adds support for page recycling for allocating receive buffers
to reduce cost of refilling RBDR ring. Also got rid of using
compound pages when pagesize is 4K, only order-0 pages now.
Only page is recycled, DMA mappings still needs to be done for
every receive buffer allocated due to following constraints
- Cannot have just one receive buffer per 64KB page.
- There is just one buffer ring shared across 8 Rx queues, so
buffers of same page can go to any Rx queue.
- HW gives buffer address where packet has been DMA'ed and not
the index into buffer ring.
This makes it not possible to resue DMA mapping info. So unfortunately
have to go through costly mapping route for every buffer.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jiri Pirko [Tue, 2 May 2017 08:12:00 +0000 (10:12 +0200)]
net: sched: add helpers to handle extended actions
Jump is now the only one using value action opcode. This is going to
change soon. So introduce helpers to work with this. Convert TC_ACT_JUMP.
This also fixes the TC_ACT_JUMP check, which is incorrectly done as a
bit check, not a value check.
Fixes: e0ee84ded796 ("net sched actions: Complete the JUMPX opcode") Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
projects / mirror_ubuntu-eoan-kernel.git / log