Petr Mladek [Tue, 13 Dec 2016 00:45:50 +0000 (16:45 -0800)]
printk/btrfs: handle more message headers
Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") allows to define more message headers for a single
message. The motivation is that continuous lines might get mixed.
Therefore it make sense to define the right log level for every piece of
a cont line.
The current btrfs_printk() macros do not support continuous lines at the
moment. But better be prepared for a custom messages and avoid
potential "lvl" buffer overflow.
This patch iterates over the entire message header. It is interested
only into the message level like the original code.
This patch also introduces PRINTK_MAX_SINGLE_HEADER_LEN. Three bytes
are enough for the message level header at the moment. But it used to
be three, see the commit 04d2c8c83d0e ("printk: convert the format for
KERN_<LEVEL> to a 2 byte pattern").
Also I fixed the default ratelimit level. It looked very strange when it
was different from the default log level.
[pmladek@suse.com: Fix a check of the valid message level] Link: http://lkml.kernel.org/r/20161111183236.GD2145@dhcp128.suse.cz Link: http://lkml.kernel.org/r/1478695291-12169-4-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: David Sterba <dsterba@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Tue, 13 Dec 2016 00:45:47 +0000 (16:45 -0800)]
printk/kdb: handle more message headers
Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") allows to define more message headers for a single
message. The motivation is that continuous lines might get mixed.
Therefore it make sense to define the right log level for every piece of
a cont line.
This patch introduces printk_skip_headers() that will skip all headers
and uses it in the kdb code instead of printk_skip_level().
This approach helps to fix other printk_skip_level() users
independently.
Link: http://lkml.kernel.org/r/1478695291-12169-3-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: David Sterba <dsterba@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Tue, 13 Dec 2016 00:45:44 +0000 (16:45 -0800)]
printk/NMI: handle continuous lines and missing newline
Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") added back KERN_CONT message header. As a result
it might appear in the middle of the line when the parts are squashed
via the temporary NMI buffer.
A reasonable solution seems to be to split the text in the NNI temporary
not only by newlines but also by the message headers.
Another solution would be to filter out KERN_CONT when writing to the
temporary buffer. But this would complicate the lockless handling.
Also it would not solve problems with a missing newline that was there
even before the KERN_CONT stuff.
This patch moves the temporary buffer handling into separate function.
I played with it and it seems that using the char pointers make the code
easier to read.
Also it prints the final newline as a continuous line.
Finally, it moves handling of the s->len overflow into the paranoid
check. And allows to recover from the disaster.
Link: http://lkml.kernel.org/r/1478695291-12169-2-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: David Sterba <dsterba@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Tue, 13 Dec 2016 00:45:40 +0000 (16:45 -0800)]
printk/NMI: fix up handling of the full nmi log buffer
vsnprintf() adds the trailing '\0' but it does not count it into the
number of printed characters. The result is that there is one byte less
space for the real characters in the buffer.
The broken check for the free space might cause that we will repeatedly
try to print 1 character into the buffer, never reach the full buffer,
and do not count the messages as missed.
Also vsnprintf() returns the number of characters that would be printed
if the buffer was big enough. As a result, s->len might be bigger than
the size of the buffer[*]. And the printk() function might return
bigger len than it really printed. Both problems are fixed by using
vscnprintf() instead.
Note that I though about increasing the number of missed messages even
when the message was shrunken. But it made the code even more
complicated. I think that it is not worth it. Shrunken messages are
usually easy to recognize. And it should be a corner case.
[*] The overflown s->len value is crazy and unexpected. I "made a
mistake" and reported this situation as an internal error when fixed
handling of PR_CONT headers in some other patch.
Link: http://lkml.kernel.org/r/20161208174912.GA17042@linux.suse Signed-off-by: Petr Mladek <pmladek@suse.com>
CcL Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Joe Perches <joe@perches.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa [Tue, 13 Dec 2016 00:45:35 +0000 (16:45 -0800)]
hung_task: decrement sysctl_hung_task_warnings only if it is positive
Since sysctl_hung_task_warnings == -1 is allowed (infinite warnings),
commit 48a6d64edadb ("hung_task: allow hung_task_panic when
hung_task_warnings is 0") should decrement it only when it is not -1.
This prevents the kernel from ceasing warnings after the first 4294967295 ;)
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: John Siddle <jsiddle@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoes [Tue, 13 Dec 2016 00:45:25 +0000 (16:45 -0800)]
fs/proc/array.c: slightly improve render_sigset_t
format_decode and vsnprintf occasionally show up in perf top, so I went
looking for places that might not need the full printf power. With the
help of kprobes, I gathered some statistics on which format strings we
mostly pass to vsnprintf. On a trivial desktop workload, I hit "%x" 25%
of the time, so something apparently reads /proc/pid/status (which does
5*16 printf("%x") calls) a lot.
With this patch, reading /proc/pid/status is 30% faster according to
this microbenchmark:
char buf[4096];
int i, fd;
for (i = 0; i < 10000; ++i) {
fd = open("/proc/self/status", O_RDONLY);
read(fd, buf, sizeof(buf));
close(fd);
}
Kees Cook [Tue, 13 Dec 2016 00:45:05 +0000 (16:45 -0800)]
proc: report no_new_privs state
Similar to being able to examine if a process has been correctly
confined with seccomp, the state of no_new_privs is equally interesting,
so this adds it to /proc/$pid/status.
Link: http://lkml.kernel.org/r/20161103214041.GA58566@beast Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jann Horn <jann@thejh.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rodrigo Freire <rfreire@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Robert Ho <robert.hu@intel.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zijun_hu [Tue, 13 Dec 2016 00:45:02 +0000 (16:45 -0800)]
mm/percpu.c: fix panic triggered by BUG_ON() falsely
As shown by pcpu_build_alloc_info(), the number of units within a percpu
group is deduced by rounding up the number of CPUs within the group to
@upa boundary/ Therefore, the number of CPUs isn't equal to the units's
if it isn't aligned to @upa normally. However, pcpu_page_first_chunk()
uses BUG_ON() to assert that one number is equal to the other roughly,
so a panic is maybe triggered by the BUG_ON() incorrectly.
In order to fix this issue, the number of CPUs is rounded up then
compared with units's and the BUG_ON() is replaced with a warning and
return of an error code as well, to keep system alive as much as
possible.
Andrey Ryabinin [Tue, 13 Dec 2016 00:44:59 +0000 (16:44 -0800)]
kasan: turn on -fsanitize-address-use-after-scope
In the upcoming gcc7 release, the -fsanitize=kernel-address option at
first implied new -fsanitize-address-use-after-scope option. This would
cause link errors on older kernels because they don't have two new
functions required for use-after-scope support. Therefore, gcc7 changed
default to -fno-sanitize-address-use-after-scope.
Now the kernel has everything required for that feature since commit 828347f8f9a5 ("kasan: support use-after-scope detection"). So, to make it
work, we just have to enable use-after-scope in CFLAGS.
Dmitry Vyukov [Tue, 13 Dec 2016 00:44:56 +0000 (16:44 -0800)]
kasan: eliminate long stalls during quarantine reduction
Currently we dedicate 1/32 of RAM for quarantine and then reduce it by
1/4 of total quarantine size. This can be a significant amount of
memory. For example, with 4GB of RAM total quarantine size is 128MB and
it is reduced by 32MB at a time. With 128GB of RAM total quarantine
size is 4GB and it is reduced by 1GB. This leads to several problems:
- freeing 1GB can take tens of seconds, causes rcu stall warnings and
just introduces unexpected long delays at random places
- if kmalloc() is called under a mutex, other threads stall on that
mutex while a thread reduces quarantine
- threads wait on quarantine_lock while one thread grabs a large batch
of objects to evict
- we walk the uncached list of object to free twice which makes all of
the above worse
- when a thread frees objects, they are already not accounted against
global_quarantine.bytes; as the result we can have quarantine_size
bytes in quarantine + unbounded amount of memory in large batches in
threads that are in process of freeing
Reduce size of quarantine in smaller batches to reduce the delays. The
only reason to reduce it in batches is amortization of overheads, the
new batch size of 1MB should be well enough to amortize spinlock
lock/unlock and few function calls.
Plus organize quarantine as a FIFO array of batches. This allows to not
walk the list in quarantine_reduce() under quarantine_lock, which in
turn reduces contention and is just faster.
This improves performance of heavy load (syzkaller fuzzing) by ~20% with
4 CPUs and 32GB of RAM. Also this eliminates frequent (every 5 sec)
drops of CPU consumption from ~400% to ~100% (one thread reduces
quarantine while others are waiting on a mutex).
Some reference numbers:
1. Machine with 4 CPUs and 4GB of memory. Quarantine size 128MB.
Currently we free 32MB at at time.
With new code we free 1MB at a time (1024 batches, ~128 are used).
2. Machine with 32 CPUs and 128GB of memory. Quarantine size 4GB.
Currently we free 1GB at at time.
With new code we free 8MB at a time (1024 batches, ~512 are used).
3. Machine with 4096 CPUs and 1TB of memory. Quarantine size 32GB.
Currently we free 8GB at at time.
With new code we free 4MB at a time (16K batches, ~8K are used).
Dmitry Vyukov [Tue, 13 Dec 2016 00:44:53 +0000 (16:44 -0800)]
kasan: support panic_on_warn
If user sets panic_on_warn, he wants kernel to panic if there is
anything barely wrong with the kernel. KASAN-detected errors are
definitely not less benign than an arbitrary kernel WARNING.
Panic after KASAN errors if panic_on_warn is set.
We use this for continuous fuzzing where we want kernel to stop and
reboot on any error.
Hugh Dickins [Tue, 13 Dec 2016 00:44:50 +0000 (16:44 -0800)]
mm: make transparent hugepage size public
Test programs want to know the size of a transparent hugepage. While it
is commonly the same as the size of a hugetlbfs page (shown as
Hugepagesize in /proc/meminfo), that is not always so: powerpc
implements transparent hugepages in a different way from hugetlbfs
pages, so it's coincidence when their sizes are the same; and x86 and
others can support more than one hugetlbfs page size.
Add /sys/kernel/mm/transparent_hugepage/hpage_pmd_size to show the THP
size in bytes - it's the same for Anonymous and Shmem hugepages. Call
it hpage_pmd_size (after HPAGE_PMD_SIZE) rather than hpage_size, in case
some transparent support for pud and pgd pages is added later.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052200290.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Tue, 13 Dec 2016 00:44:47 +0000 (16:44 -0800)]
mm: add cond_resched() in gather_pte_stats()
The other pagetable walks in task_mmu.c have a cond_resched() after
walking their ptes: add a cond_resched() in gather_pte_stats() too, for
reading /proc/<id>/numa_maps. Only pagemap_pmd_range() has a
cond_resched() in its (unusually expensive) pmd_trans_huge case: more
should probably be added, but leave them unchanged for now.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052157400.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Tue, 13 Dec 2016 00:44:44 +0000 (16:44 -0800)]
mm: add three more cond_resched() in swapoff
Add a cond_resched() in the unuse_pmd_range() loop (so as to call it
even when pmd none or trans_huge, like zap_pmd_range() does); and in the
unuse_mm() loop (since that might skip over many vmas). shmem_unuse()
and radix_tree_locate_item() look good enough already.
Those were the obvious places, but in fact the stalls came from
find_next_to_unuse(), which sometimes scans through many unused entries.
Apply scan_swap_map()'s LATENCY_LIMIT of 256 there too; and only go off
to test frontswap_map when a used entry is found.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052155140.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Eric Dumazet <edumazet@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Tue, 13 Dec 2016 00:44:41 +0000 (16:44 -0800)]
mm, page_alloc: keep pcp count and list contents in sync if struct page is corrupted
Vlastimil Babka pointed out that commit 479f854a207c ("mm, page_alloc:
defer debugging checks of pages allocated from the PCP") will allow the
per-cpu list counter to be out of sync with the per-cpu list contents if
a struct page is corrupted.
The consequence is an infinite loop if the per-cpu lists get fully
drained by free_pcppages_bulk because all the lists are empty but the
count is positive. The infinite loop occurs here
do {
batch_free++;
if (++migratetype == MIGRATE_PCPTYPES)
migratetype = 0;
list = &pcp->lists[migratetype];
} while (list_empty(list));
What the user sees is a bad page warning followed by a soft lockup with
interrupts disabled in free_pcppages_bulk().
This patch keeps the accounting in sync.
Fixes: 479f854a207c ("mm, page_alloc: defer debugging checks of pages allocated from the PCP") Link: http://lkml.kernel.org/r/20161202112951.23346-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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>
Vlastimil Babka [Tue, 13 Dec 2016 00:44:38 +0000 (16:44 -0800)]
mm, rmap: handle anon_vma_prepare() common case inline
anon_vma_prepare() is mostly a large "if (unlikely(...))" block, as the
expected common case is that an anon_vma already exists. We could turn
the condition around and return 0, but it also makes sense to do it
inline and avoid a call for the common case.
Bloat-o-meter naturally shows that inlining the check has some code size
costs:
Vlastimil Babka [Tue, 13 Dec 2016 00:44:35 +0000 (16:44 -0800)]
mm, debug: print raw struct page data in __dump_page()
__dump_page() is used when a page metadata inconsistency is detected,
either by standard runtime checks, or extra checks in CONFIG_DEBUG_VM
builds. It prints some of the relevant metadata, but not the whole
struct page, which is based on unions and interpretation is dependent on
the context.
This means that sometimes e.g. a VM_BUG_ON_PAGE() checks certain field,
which is however not printed by __dump_page() and the resulting bug
report may then lack clues that could help in determining the root
cause. This patch solves the problem by simply printing the whole
struct page word by word, so no part is missing, but the interpretation
of the data is left to developers. This is similar to e.g. x86_64 raw
stack dumps.
Add arch specific callback in the generic THP page cache code that will
deposit and withdarw preallocated page table. Archs like ppc64 use this
preallocated table to store the hash pte slot information.
Testing:
kernel build of the patch series on tmpfs mounted with option huge=always
mm: move vma_is_anonymous check within pmd_move_must_withdraw
Independent of whether the vma is for anonymous memory, some arches like
ppc64 would like to override pmd_move_must_withdraw().
One option is to encapsulate the vma_is_anonymous() check for general
architectures inside pmd_move_must_withdraw() so that is always called
and architectures that need unconditional overriding can override this
function. ppc64 needs to override the function when the MMU is
configured to use hash PTE's.
[bsingharora@gmail.com: reworked changelog] Link: http://lkml.kernel.org/r/20161113150025.17942-1-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joel Fernandes [Tue, 13 Dec 2016 00:44:26 +0000 (16:44 -0800)]
mm: add preempt points into __purge_vmap_area_lazy()
Use cond_resched_lock to avoid holding the vmap_area_lock for a
potentially long time and thus creating bad latencies for various
workloads.
[hch: split from a larger patch by Joel, wrote the crappy changelog] Link: http://lkml.kernel.org/r/1479474236-4139-11-git-send-email-hch@lst.de Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Jisheng Zhang <jszhang@marvell.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Dias <joaodias@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The purge_lock spinlock causes high latencies with non RT kernel. This
has been reported multiple times on lkml [1] [2] and affects
applications like audio.
This patch replaces it with a mutex to allow preemption while holding
the lock.
Thanks to Joel Fernandes for the detailed report and analysis as well as
an earlier attempt at fixing this issue.
Andrey Ryabinin [Tue, 13 Dec 2016 00:44:10 +0000 (16:44 -0800)]
mm: add vfree_atomic()
We are going to use sleeping lock for freeing vmap. However some
vfree() users want to free memory from atomic (but not from interrupt)
context. For this we add vfree_atomic() - deferred variation of vfree()
which can be used in any atomic context (except NMIs).
[akpm@linux-foundation.org: tweak comment grammar]
[aryabinin@virtuozzo.com: use raw_cpu_ptr() instead of this_cpu_ptr()] Link: http://lkml.kernel.org/r/1481553981-3856-1-git-send-email-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/1479474236-4139-5-git-send-email-hch@lst.de Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Jisheng Zhang <jszhang@marvell.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Dias <joaodias@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the purge_lock synchronization to the callers, move the call to
purge_fragmented_blocks_allcpus at the beginning of the function to the
callers that need it, move the force_flush behavior to the caller that
needs it, and pass start and end by value instead of by reference.
No change in behavior.
Link: http://lkml.kernel.org/r/1479474236-4139-4-git-send-email-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Jisheng Zhang <jszhang@marvell.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Dias <joaodias@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:58 +0000 (16:43 -0800)]
mm: workingset: update shadow limit to reflect bigger active list
Since commit 59dc76b0d4df ("mm: vmscan: reduce size of inactive file
list") the size of the active file list is no longer limited to half of
memory. Increase the shadow node limit accordingly to avoid throwing
out shadow entries that might still result in eligible refaults.
The exact size of the active list now depends on the overall size of the
page cache, but converges toward taking up most of the space:
It would be possible to apply the same precise ratios when determining
the limit for radix tree nodes containing shadow entries, but since it
is merely an approximation of the oldest refault distances in the wild
and the code also makes assumptions about the node population density,
keep it simple and always target the full cache size.
While at it, clarify the comment and the formula for memory footprint.
Link: http://lkml.kernel.org/r/20161117214701.29000-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> 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>
Johannes Weiner [Tue, 13 Dec 2016 00:43:55 +0000 (16:43 -0800)]
mm: workingset: restore refault tracking for single-page files
Shadow entries in the page cache used to be accounted behind the radix
tree implementation's back in the upper bits of node->count, and the
radix tree code extending a single-entry tree with a shadow entry in
root->rnode would corrupt that counter. As a result, we could not put
shadow entries at index 0 if the tree didn't have any other entries, and
that means no refault detection for any single-page file.
Now that the shadow entries are tracked natively in the radix tree's
exceptional counter, this is no longer necessary. Extending and
shrinking the tree from and to single entries in root->rnode now does
the right thing when the entry is exceptional, remove that limitation.
Link: http://lkml.kernel.org/r/20161117193244.GF23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:52 +0000 (16:43 -0800)]
mm: workingset: move shadow entry tracking to radix tree exceptional tracking
Currently, we track the shadow entries in the page cache in the upper
bits of the radix_tree_node->count, behind the back of the radix tree
implementation. Because the radix tree code has no awareness of them,
we rely on random subtleties throughout the implementation (such as the
node->count != 1 check in the shrinking code, which is meant to exclude
multi-entry nodes but also happens to skip nodes with only one shadow
entry, as that's accounted in the upper bits). This is error prone and
has, in fact, caused the bug fixed in d3798ae8c6f3 ("mm: filemap: don't
plant shadow entries without radix tree node").
To remove these subtleties, this patch moves shadow entry tracking from
the upper bits of node->count to the existing counter for exceptional
entries. node->count goes back to being a simple counter of valid
entries in the tree node and can be shrunk to a single byte.
This vastly simplifies the page cache code. All accounting happens
natively inside the radix tree implementation, and maintaining the LRU
linkage of shadow nodes is consolidated into a single function in the
workingset code that is called for leaf nodes affected by a change in
the page cache tree.
This also removes the last user of the __radix_delete_node() return
value. Eliminate it.
Link: http://lkml.kernel.org/r/20161117193211.GE23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:49 +0000 (16:43 -0800)]
lib: radix-tree: update callback for changing leaf nodes
Support handing __radix_tree_replace() a callback that gets invoked for
all leaf nodes that change or get freed as a result of the slot
replacement, to assist users tracking nodes with node->private_list.
This prepares for putting page cache shadow entries into the radix tree
root again and drastically simplifying the shadow tracking.
Link: http://lkml.kernel.org/r/20161117193134.GD23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:46 +0000 (16:43 -0800)]
lib: radix-tree: add entry deletion support to __radix_tree_replace()
Page cache shadow entry handling will be a lot simpler when it can use a
single generic replacement function for pages, shadow entries, and
emptying slots.
Make __radix_tree_replace() properly account insertions and deletions in
node->count and garbage collect nodes as they become empty. Then
re-implement radix_tree_delete() on top of it.
Link: http://lkml.kernel.org/r/20161117193058.GC23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:43 +0000 (16:43 -0800)]
lib: radix-tree: check accounting of existing slot replacement users
The bug in khugepaged fixed earlier in this series shows that radix tree
slot replacement is fragile; and it will become more so when not only
NULL<->!NULL transitions need to be caught but transitions from and to
exceptional entries as well. We need checks.
Re-implement radix_tree_replace_slot() on top of the sanity-checked
__radix_tree_replace(). This requires existing callers to also pass the
radix tree root, but it'll warn us when somebody replaces slots with
contents that need proper accounting (transitions between NULL entries,
real entries, exceptional entries) and where a replacement through the
slot pointer would corrupt the radix tree node counts.
Link: http://lkml.kernel.org/r/20161117193021.GB23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:41 +0000 (16:43 -0800)]
lib: radix-tree: native accounting of exceptional entries
The way the page cache is sneaking shadow entries of evicted pages into
the radix tree past the node entry accounting and tracking them manually
in the upper bits of node->count is fraught with problems.
These shadow entries are marked in the tree as exceptional entries,
which are a native concept to the radix tree. Maintain an explicit
counter of exceptional entries in the radix tree node. Subsequent
patches will switch shadow entry tracking over to that counter.
DAX and shmem are the other users of exceptional entries. Since slot
replacements that change the entry type from regular to exceptional must
now be accounted, introduce a __radix_tree_replace() function that does
replacement and accounting, and switch DAX and shmem over.
The increase in radix tree node size is temporary. A followup patch
switches the shadow tracking to this new scheme and we'll no longer need
the upper bits in node->count and shrink that back to one byte.
Link: http://lkml.kernel.org/r/20161117192945.GA23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:38 +0000 (16:43 -0800)]
mm: workingset: turn shadow node shrinker bugs into warnings
When the shadow page shrinker tries to reclaim a radix tree node but
finds it in an unexpected state - it should contain no pages, and
non-zero shadow entries - there is no need to kill the executing task or
even the entire system. Warn about the invalid state, then leave that
tree node be. Simply don't put it back on the shadow LRU for future
reclaim and move on.
Link: http://lkml.kernel.org/r/20161117191138.22769-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:35 +0000 (16:43 -0800)]
mm: khugepaged: fix radix tree node leak in shmem collapse error path
The radix tree counts valid entries in each tree node. Entries stored
in the tree cannot be removed by simpling storing NULL in the slot or
the internal counters will be off and the node never gets freed again.
When collapsing a shmem page fails, restore the holes that were filled
with radix_tree_insert() with a proper radix tree deletion.
Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") Link: http://lkml.kernel.org/r/20161117191138.22769-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Jan Kara <jack@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Tue, 13 Dec 2016 00:43:32 +0000 (16:43 -0800)]
mm: khugepaged: close use-after-free race during shmem collapsing
Patch series "mm: workingset: radix tree subtleties & single-page file
refaults", v3.
This is another revision of the radix tree / workingset patches based on
feedback from Jan and Kirill.
This is a follow-up to d3798ae8c6f3 ("mm: filemap: don't plant shadow
entries without radix tree node"). That patch fixed an issue that was
caused mainly by the page cache sneaking special shadow page entries
into the radix tree and relying on subtleties in the radix tree code to
make that work. The fix also had to stop tracking refaults for
single-page files because shadow pages stored as direct pointers in
radix_tree_root->rnode weren't properly handled during tree extension.
These patches make the radix tree code explicitely support and track
such special entries, to eliminate the subtleties and to restore the
thrash detection for single-page files.
This patch (of 9):
When a radix tree iteration drops the tree lock, another thread might
swoop in and free the node holding the current slot. The iteration
needs to do another tree lookup from the current index to continue.
[kirill.shutemov@linux.intel.com: re-lookup for replacement] Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") Link: http://lkml.kernel.org/r/20161117191138.22769-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jens Axboe [Tue, 13 Dec 2016 00:43:26 +0000 (16:43 -0800)]
mm: don't cap request size based on read-ahead setting
We ran into a funky issue, where someone doing 256K buffered reads saw
128K requests at the device level. Turns out it is read-ahead capping
the request size, since we use 128K as the default setting. This
doesn't make a lot of sense - if someone is issuing 256K reads, they
should see 256K reads, regardless of the read-ahead setting, if the
underlying device can support a 256K read in a single command.
This patch introduces a bdi hint, io_pages. This is the soft max IO
size for the lower level, I've hooked it up to the bdev settings here.
Read-ahead is modified to issue the maximum of the user request size,
and the read-ahead max size, but capped to the max request size on the
device side. The latter is done to avoid reading ahead too much, if the
application asks for a huge read. With this patch, the kernel behaves
like the application expects.
Link: http://lkml.kernel.org/r/1479498073-8657-1-git-send-email-axboe@fb.com Signed-off-by: Jens Axboe <axboe@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem: fix compilation warnings on unused functions
Compiling shmem.c with SHMEM and TRANSAPRENT_HUGE_PAGECACHE enabled
raises warnings on two unused functions when CONFIG_TMPFS and
CONFIG_SYSFS are both disabled:
mm/shmem.c:390:20: warning: `shmem_format_huge' defined but not used [-Wunused-function]
static const char *shmem_format_huge(int huge)
^~~~~~~~~~~~~~~~~
mm/shmem.c:373:12: warning: `shmem_parse_huge' defined but not used [-Wunused-function]
static int shmem_parse_huge(const char *str)
^~~~~~~~~~~~~~~~
A conditional compilation on tmpfs or sysfs removes the warnings.
Thierry Reding [Tue, 13 Dec 2016 00:43:15 +0000 (16:43 -0800)]
mm: cma: make linux/cma.h standalone includible
The header uses types and definitions from the linux/init.h as well as
linux/types.h headers without explicitly including them. This causes a
failure to compile if they are not implicitly pulled in by includers.
Dan Williams [Tue, 13 Dec 2016 00:43:12 +0000 (16:43 -0800)]
mm: disable numa migration faults for dax vmas
Mark dax vmas as not migratable to exclude them from task_numa_work().
This is especially relevant for device-dax which wants to ensure
predictable access latency and not incur periodic faults.
[akpm@linux-foundation.org: add comment] Link: http://lkml.kernel.org/r/147892450132.22062.16875659431109209179.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Heiko Carstens [Tue, 13 Dec 2016 00:43:09 +0000 (16:43 -0800)]
mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected
Having code for the pkey_mprotect, pkey_alloc and pkey_free system calls
makes only sense if ARCH_HAS_PKEYS is selected. If not selected these
system calls will always return -ENOSPC or -EINVAL.
To simplify things and have less code generate the pkey system call code
only if ARCH_HAS_PKEYS is selected.
For architectures which have already wired up the system calls, but do
not select ARCH_HAS_PKEYS this will result in less generated code and a
different return code: the three system calls will now always return
-ENOSYS, using the cond_syscall mechanism.
For architectures which have not wired up the system calls less
unreachable code will be generated.
Link: http://lkml.kernel.org/r/20161114111251.70084-1-heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reza Arbab [Tue, 13 Dec 2016 00:42:55 +0000 (16:42 -0800)]
mm: remove x86-only restriction of movable_node
In commit c5320926e370 ("mem-hotplug: introduce movable_node boot
option"), the memblock allocation direction is changed to bottom-up and
then back to top-down like this:
1. memblock_set_bottom_up(true), called by cmdline_parse_movable_node().
2. memblock_set_bottom_up(false), called by x86's numa_init().
Even though (1) occurs in generic mm code, it is wrapped by #ifdef
CONFIG_MOVABLE_NODE, which depends on X86_64.
This means that when we extend CONFIG_MOVABLE_NODE to non-x86 arches,
things will be unbalanced. (1) will happen for them, but (2) will not.
This toggle was added in the first place because x86 has a delay between
adding memblocks and marking them as hotpluggable. Since other arches
do this marking either immediately or not at all, they do not require
the bottom-up toggle.
So, resolve things by moving (1) from cmdline_parse_movable_node() to
x86's setup_arch(), immediately after the movable_node parameter has
been parsed.
Link: http://lkml.kernel.org/r/1479160961-25840-3-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alistair Popple <apopple@au1.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reza Arbab [Tue, 13 Dec 2016 00:42:52 +0000 (16:42 -0800)]
powerpc/mm: allow memory hotplug into a memoryless node
Patch series "enable movable nodes on non-x86 configs", v7.
This patchset allows more configs to make use of movable nodes. When
CONFIG_MOVABLE_NODE is selected, there are two ways to introduce such
nodes into the system:
1. Discover movable nodes at boot. Currently this is only possible on
x86, but we will enable configs supporting fdt to do the same.
2. Hotplug and online all of a node's memory using online_movable. This
is already possible on any config supporting memory hotplug, not
just x86, but the Kconfig doesn't say so. We will fix that.
We'll also remove some cruft on power which would prevent (2).
This patch (of 5):
Remove the check which prevents us from hotplugging into an empty node.
The original commit b226e4621245 ("[PATCH] powerpc: don't add memory to
empty node/zone"), states that this was intended to be a temporary measure.
It is a workaround for an oops which no longer occurs.
Link: http://lkml.kernel.org/r/1479160961-25840-2-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alistair Popple <apopple@au1.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mempolicy.c: forbid static or relative flags for local NUMA mode
The MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES flags are irrelevant
when setting them for MPOL_LOCAL NUMA memory policy via set_mempolicy or
mbind.
Return the "invalid argument" from set_mempolicy and mbind whenever any
of these flags is passed along with MPOL_LOCAL.
It is consistent with MPOL_PREFERRED passed with empty nodemask.
It slightly shortens the execution time in paths where these flags are
used e.g. when trying to rebind the NUMA nodes for changes in cgroups
cpuset mems (mpol_rebind_preferred()) or when just printing the mempolicy
structure (/proc/PID/numa_maps). Isolated tests done.
Link: http://lkml.kernel.org/r/20161027163037.4089-1-kwapulinski.piotr@gmail.com Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Liang Chen <liangchen.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lorenzo Stoakes [Tue, 13 Dec 2016 00:42:46 +0000 (16:42 -0800)]
mm: fix up get_user_pages* comments
In the previous round of get_user_pages* changes comments attached to
__get_user_pages_unlocked() and get_user_pages_unlocked() were rendered
incorrect, this patch corrects them.
In addition the get_user_pages_unlocked() comment seems to have already
been outdated as it referred to tsk, mm parameters which were removed in c12d2da5 ("mm/gup: Remove the macro overload API migration helpers from
the get_user*() APIs"), this patch fixes this also.
Link: http://lkml.kernel.org/r/20161025233435.5338-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@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>
mm: remove the page size change check in tlb_remove_page
Now that we check for page size change early in the loop, we can
partially revert e9d55e157034a ("mm: change the interface for
__tlb_remove_page").
This simplies the code much, by removing the need to track the last
address with which we adjusted the range. We also go back to the older
way of filling the mmu_gather array, ie, we add an entry and then check
whether the gather batch is full.
Link: http://lkml.kernel.org/r/20161026084839.27299-6-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: add tlb_remove_check_page_size_change to track page size change
With commit e77b0852b551 ("mm/mmu_gather: track page size with mmu
gather and force flush if page size change") we added the ability to
force a tlb flush when the page size change in a mmu_gather loop. We
did that by checking for a page size change every time we added a page
to mmu_gather for lazy flush/remove. We can improve that by moving the
page size change check early and not doing it every time we add a page.
This also helps us to do tlb flush when invalidating a range covering
dax mapping. Wrt dax mapping we don't have a backing struct page and
hence we don't call tlb_remove_page, which earlier forced the tlb flush
on page size change. Moving the page size change check earlier means we
will do the same even for dax mapping.
We also avoid doing this check on architecture other than powerpc.
In a later patch we will remove page size check from tlb_remove_page().
Link: http://lkml.kernel.org/r/20161026084839.27299-5-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We use __tlb_adjust_range to update range convered by mmu_gather struct.
We later use the 'start' and 'end' to do a mmu_notifier_invalidate_range
in tlb_flush_mmu_tlbonly(). Update the 'end' correctly in
__tlb_adjust_range so that we call mmu_notifier_invalidate_range with
the correct range values.
Wrt tlbflush, this should not have any impact, because a flush with
correct start address will flush tlb mapping for the range.
Also add comment w.r.t updating the range when we free pagetable pages.
For now we don't support a range based page table cache flush.
Link: http://lkml.kernel.org/r/20161026084839.27299-3-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arnd Bergmann [Tue, 13 Dec 2016 00:42:28 +0000 (16:42 -0800)]
shmem: avoid maybe-uninitialized warning
After enabling -Wmaybe-uninitialized warnings, we get a false-postive
warning for shmem:
mm/shmem.c: In function `shmem_getpage_gfp':
include/linux/spinlock.h:332:21: error: `info' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This can be easily avoided, since the correct 'info' pointer is known at
the time we first enter the function, so we can simply move the
initialization up. Moving it before the first label avoids the warning
and lets us remove two later initializations.
Note that the function is so hard to read that it not only confuses the
compiler, but also most readers and without this patch it could\ easily
break if one of the 'goto's changed.
Link: https://www.spinics.net/lists/kernel/msg2368133.html Link: http://lkml.kernel.org/r/20161024205725.786455-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ming Ling [Tue, 13 Dec 2016 00:42:26 +0000 (16:42 -0800)]
mm, compaction: fix NR_ISOLATED_* stats for pfn based migration
Since commit bda807d44454 ("mm: migrate: support non-lru movable page
migration") isolate_migratepages_block) can isolate !PageLRU pages which
would acct_isolated account as NR_ISOLATED_*. Accounting these non-lru
pages NR_ISOLATED_{ANON,FILE} doesn't make any sense and it can misguide
heuristics based on those counters such as pgdat_reclaimable_pages resp.
too_many_isolated which would lead to unexpected stalls during the
direct reclaim without any good reason. Note that
__alloc_contig_migrate_range can isolate a lot of pages at once.
On mobile devices such as 512M ram android Phone, it may use a big zram
swap. In some cases zram(zsmalloc) uses too many non-lru but
migratedable pages, such as:
MemTotal: 468148 kB
Normal free:5620kB
Free swap:4736kB
Total swap:409596kB
ZRAM: 164616kB(zsmalloc non-lru pages)
active_anon:60700kB
inactive_anon:60744kB
active_file:34420kB
inactive_file:37532kB
Fix this by only accounting lru pages to NR_ISOLATED_* in
isolate_migratepages_block right after they were isolated and we still
know they were on LRU. Drop acct_isolated because it is called after
the fact and we've lost that information. Batching per-cpu counter
doesn't make much improvement anyway. Also make sure that we uncharge
only LRU pages when putting them back on the LRU in
putback_movable_pages resp. when unmap_and_move migrates the page.
[mhocko@suse.com: replace acct_isolated() with direct counting] Fixes: bda807d44454 ("mm: migrate: support non-lru movable page migration") Link: http://lkml.kernel.org/r/20161019080240.9682-1-mhocko@kernel.org Signed-off-by: Ming Ling <ming.ling@spreadtrum.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Tue, 13 Dec 2016 00:42:23 +0000 (16:42 -0800)]
mm, mempolicy: clean up __GFP_THISNODE confusion in policy_zonelist
__GFP_THISNODE is documented to enforce the allocation to be satisified
from the requested node with no fallbacks or placement policy
enforcements. policy_zonelist seemingly breaks this semantic if the
current policy is MPOL_MBIND and instead of taking the node it will
fallback to the first node in the mask if the requested one is not in
the mask. This is confusing to say the least because it fact we
shouldn't ever go that path. First tasks shouldn't be scheduled on CPUs
with nodes outside of their mempolicy binding. And secondly
policy_zonelist is called only from 3 places:
- huge_zonelist - never should do __GFP_THISNODE when going this path
- alloc_pages_vma - which shouldn't depend on __GFP_THISNODE either
- alloc_pages_current - which uses default_policy id __GFP_THISNODE is
used
So we shouldn't even need to care about this possibility and can drop
the confusing code. Let's keep a WARN_ON_ONCE in place to catch
potential users and fix them up properly (aka use a different allocation
function which ignores mempolicy).
David Rientjes [Tue, 13 Dec 2016 00:42:20 +0000 (16:42 -0800)]
mm, thp: avoid unlikely branches for split_huge_pmd
While doing MADV_DONTNEED on a large area of thp memory, I noticed we
encountered many unlikely() branches in profiles for each backing
hugepage. This is because zap_pmd_range() would call split_huge_pmd(),
which rechecked the conditions that were already validated, but as part
of an unlikely() branch.
Avoid the unlikely() branch when in a context where pmd is known to be
good for __split_huge_pmd() directly.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1610181600300.84525@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many seq_file helpers exist for simplifying implementation of virtual
files especially, for /proc nodes. however, the helpers for iteration
over list_head are available but aren't adopted to implement
/proc/vmallocinfo currently.
Simplify /proc/vmallocinfo implementation by using existing seq_file
helpers.
Link: http://lkml.kernel.org/r/57FDF2E5.1000201@zoho.com Signed-off-by: zijun_hu <zijun_hu@htc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Tue, 13 Dec 2016 00:42:14 +0000 (16:42 -0800)]
mm: make unreserve highatomic functions reliable
Currently, unreserve_highatomic_pageblock bails out if it found
highatomic pageblock regardless of really moving free pages from the one
so that it could mitigate unreserve logic's goal which saves OOM of a
process.
This patch makes unreserve functions bail out only if it moves some
pages out of !highatomic free list to avoid such false positive.
Another potential problem is that by race between page freeing and
reserve highatomic function, pages could be in highatomic free list even
though the pageblock is !high atomic migratetype. In that case,
unreserve_highatomic_pageblock can be void if count of highatomic
reserve is less than pageblock_nr_pages. We could solve it simply via
draining all of reserved pages before the OOM. It would have a
safeguard role to exhuast reserved pages before converging to OOM.
Link: http://lkml.kernel.org/r/1476259429-18279-5-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Tue, 13 Dec 2016 00:42:11 +0000 (16:42 -0800)]
mm: try to exhaust highatomic reserve before the OOM
I got OOM report from production team with v4.4 kernel. It had enough
free memory but failed to allocate GFP_KERNEL order-0 page and finally
encountered OOM kill. It occured during QA process which launches
several apps, switching and so on. It happned rarely. IOW, In normal
situation, it was not a problem but if we are unluck so that several
apps uses peak memory at the same time, it can happen. If we manage to
pass the phase, the system can go working well.
I could reproduce it with my test(memory spike easily. Look at below.
The reason is free pages(19M) of DMA32 zone are reserved for
HIGHORDERATOMIC and doesn't unreserved before the OOM.
It's weird to show that zone has enough free memory above min watermark
but OOMed with 4K GFP_KERNEL allocation due to reserved highatomic
pages. As last resort, try to unreserve highatomic pages again and if
it has moved pages to non-highatmoc free list, retry reclaim once more.
Link: http://lkml.kernel.org/r/1476259429-18279-4-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Tue, 13 Dec 2016 00:42:08 +0000 (16:42 -0800)]
mm: prevent double decrease of nr_reserved_highatomic
There is race between page freeing and unreserved highatomic.
CPU 0 CPU 1
free_hot_cold_page
mt = get_pfnblock_migratetype
set_pcppage_migratetype(page, mt)
unreserve_highatomic_pageblock
spin_lock_irqsave(&zone->lock)
move_freepages_block
set_pageblock_migratetype(page)
spin_unlock_irqrestore(&zone->lock)
free_pcppages_bulk
__free_one_page(mt) <- mt is stale
By above race, a page on CPU 0 could go non-highorderatomic free list
since the pageblock's type is changed. By that, unreserve logic of
highorderatomic can decrease reserved count on a same pageblock severak
times and then it will make mismatch between nr_reserved_highatomic and
the number of reserved pageblock.
So, this patch verifies whether the pageblock is highatomic or not and
decrease the count only if the pageblock is highatomic.
Link: http://lkml.kernel.org/r/1476259429-18279-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Tue, 13 Dec 2016 00:42:05 +0000 (16:42 -0800)]
mm: don't steal highatomic pageblock
Patch series "use up highorder free pages before OOM", v3.
I got OOM report from production team with v4.4 kernel. It had enough
free memory but failed to allocate GFP_KERNEL order-0 page and finally
encountered OOM kill. It occured during QA process which launches
several apps, switching and so on. It happned rarely. IOW, In normal
situation, it was not a problem but if we are unluck so that several
apps uses peak memory at the same time, it can happen. If we manage to
pass the phase, the system can go working well.
I could reproduce it with my test(memory spike easily. Look at below.
The reason is free pages(19M) of DMA32 zone are reserved for
HIGHORDERATOMIC and doesn't unreserved before the OOM.
During the investigation, I found some problems with highatomic so this
patch aims to solve the problems and the final goal is to unreserve
every highatomic free pages before the OOM kill.
This patch (of 4):
In page freeing path, migratetype is racy so that a highorderatomic page
could free into non-highorderatomic free list. If that page is
allocated, VM can change the pageblock from higorderatomic to something.
In that case, highatomic pageblock accounting is broken so it doesn't
work(e.g., VM cannot reserve highorderatomic pageblocks any more
although it doesn't reach 1% limit).
So, this patch prohibits the changing from highatomic to other type.
It's no problem because MIGRATE_HIGHATOMIC is not listed in fallback
array so stealing will only happen due to unexpected races which is
really rare. Also, such prohibiting keeps highatomic pageblock more
longer so it would be better for highorderatomic page allocation.
Link: http://lkml.kernel.org/r/1476259429-18279-2-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/hugetlb.c: use the right pte val for compare in hugetlb_cow
We cannot use the pte value used in set_pte_at for pte_same comparison,
because archs like ppc64, filter/add new pte flag in set_pte_at.
Instead fetch the pte value inside hugetlb_cow. We are comparing pte
value to make sure the pte didn't change since we dropped the page table
lock. hugetlb_cow get called with page table lock held, and we can take
a copy of the pte value before we drop the page table lock.
With hugetlbfs, we optimize the MAP_PRIVATE write fault path with no
previous mapping (huge_pte_none entries), by forcing a cow in the fault
path. This avoid take an addition fault to covert a read-only mapping
to read/write. Here we were comparing a recently instantiated pte (via
set_pte_at) to the pte values from linux page table. As explained above
on ppc64 such pte_same check returned wrong result, resulting in us
taking an additional fault on ppc64.
Fixes: 6a119eae942c ("powerpc/mm: Add a _PAGE_PTE bit") Link: http://lkml.kernel.org/r/20161018154245.18023-1-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reported-by: Jan Stancek <jstancek@redhat.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Scott Wood <scottwood@freescale.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li [Tue, 13 Dec 2016 00:41:50 +0000 (16:41 -0800)]
mm/vmscan.c: set correct defer count for shrinker
Our system uses significantly more slab memory with memcg enabled with
the latest kernel. With 3.10 kernel, slab uses 2G memory, while with
4.6 kernel, 6G memory is used. The shrinker has problem. Let's see we
have two memcg for one shrinker. In do_shrink_slab:
1. Check cg1. nr_deferred = 0, assume total_scan = 700. batch size
is 1024, then no memory is freed. nr_deferred = 700
2. Check cg2. nr_deferred = 700. Assume freeable = 20, then
total_scan = 10 or 40. Let's assume it's 10. No memory is freed.
nr_deferred = 10.
The deferred share of cg1 is lost in this case. kswapd will free no
memory even run above steps again and again.
The fix makes sure one memcg's deferred share isn't lost.
Link: http://lkml.kernel.org/r/2414be961b5d25892060315fbb56bb19d81d0c07.1476227351.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andi Kleen [Tue, 13 Dec 2016 00:41:47 +0000 (16:41 -0800)]
mm/mprotect.c: don't touch single threaded PTEs which are on the right node
We had some problems with pages getting unmapped in single threaded
affinitized processes. It was tracked down to NUMA scanning.
In this case it doesn't make any sense to unmap pages if the process is
single threaded and the page is already on the node the process is
running on.
Add a check for this case into the numa protection code, and skip
unmapping if true.
In theory the process could be migrated later, but we will eventually
rescan and unmap and migrate then.
In theory this could be made more fancy: remembering this state per
process or even whole mm. However that would need extra tracking and be
more complicated, and the simple check seems to work fine so far.
David Rientjes [Tue, 13 Dec 2016 00:41:44 +0000 (16:41 -0800)]
mm, slab: maintain total slab count instead of active count
Rather than tracking the number of active slabs for each node, track the
total number of slabs. This is a minor improvement that avoids active
slab tracking when a slab goes from free to partial or partial to free.
For slab debugging, this also removes an explicit free count since it
can easily be inferred by the difference in number of total objects and
number of active objects.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1612042020110.115755@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Thelen <gthelen@google.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg Thelen [Tue, 13 Dec 2016 00:41:41 +0000 (16:41 -0800)]
mm, slab: faster active and free stats
Reading /proc/slabinfo or monitoring slabtop(1) can become very
expensive if there are many slab caches and if there are very lengthy
per-node partial and/or free lists.
Commit 07a63c41fa1f ("mm/slab: improve performance of gathering slabinfo
stats") addressed the per-node full lists which showed a significant
improvement when no objects were freed. This patch has the same
motivation and optimizes the remainder of the usecases where there are
very lengthy partial and free lists.
This patch maintains per-node active_slabs (full and partial) and
free_slabs rather than iterating the lists at runtime when reading
/proc/slabinfo.
When allocating 100GB of slab from a test cache where every slab page is
on the partial list, reading /proc/slabinfo (includes all other slab
caches on the system) takes ~247ms on average with 48 samples.
As a result of this patch, the same read takes ~0.856ms on average.
[rientjes@google.com: changelog] Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1611081505240.13403@chino.kir.corp.google.com Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Garnier [Tue, 13 Dec 2016 00:41:38 +0000 (16:41 -0800)]
mm/slab_common.c: check kmem_create_cache flags are common
Verify that kmem_create_cache flags are not allocator specific. It is
done before removing flags that are not available with the current
configuration.
The current kmem_cache_create removes incorrect flags but do not
validate the callers are using them right. This change will ensure that
callers are not trying to create caches with flags that won't be used
because allocator specific.
Link: http://lkml.kernel.org/r/1478553075-120242-2-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arnd Bergmann [Tue, 13 Dec 2016 00:41:35 +0000 (16:41 -0800)]
slub: avoid false-postive warning
The slub allocator gives us some incorrect warnings when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set, as the unlikely() macro
prevents it from seeing that the return code matches what it was before:
mm/slub.c: In function `kmem_cache_free_bulk':
mm/slub.c:262:23: error: `df.s' may be used uninitialized in this function [-Werror=maybe-uninitialized]
mm/slub.c:2943:3: error: `df.cnt' may be used uninitialized in this function [-Werror=maybe-uninitialized]
mm/slub.c:2933:4470: error: `df.freelist' may be used uninitialized in this function [-Werror=maybe-uninitialized]
mm/slub.c:2943:3: error: `df.tail' may be used uninitialized in this function [-Werror=maybe-uninitialized]
I have not been able to come up with a perfect way for dealing with
this, the three options I see are:
- add a bogus initialization, which would increase the runtime overhead
- replace unlikely() with unlikely_notrace()
- remove the unlikely() annotation completely
I checked the object code for a typical x86 configuration and the last
two cases produce the same result, so I went for the last one, which is
the simplest.
Link: http://lkml.kernel.org/r/20161024155704.3114445-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Tue, 13 Dec 2016 00:41:32 +0000 (16:41 -0800)]
slub: move synchronize_sched out of slab_mutex on shrink
synchronize_sched() is a heavy operation and calling it per each cache
owned by a memory cgroup being destroyed may take quite some time. What
is worse, it's currently called under the slab_mutex, stalling all works
doing cache creation/destruction.
Actually, there isn't much point in calling synchronize_sched() for each
cache - it's enough to call it just once - after setting cpu_partial for
all caches and before shrinking them. This way, we can also move it out
of the slab_mutex, which we have to hold for iterating over the slab
cache list.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=172991 Link: http://lkml.kernel.org/r/0a10d71ecae3db00fb4421bcd3f82bcc911f4be4.1475329751.git.vdavydov.dev@gmail.com Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Tue, 13 Dec 2016 00:41:29 +0000 (16:41 -0800)]
mm: memcontrol: use special workqueue for creating per-memcg caches
Creating a lot of cgroups at the same time might stall all worker
threads with kmem cache creation works, because kmem cache creation is
done with the slab_mutex held. The problem was amplified by commits 801faf0db894 ("mm/slab: lockless decision to grow cache") in case of
SLAB and 81ae6d03952c ("mm/slub.c: replace kick_all_cpus_sync() with
synchronize_sched() in kmem_cache_shrink()") in case of SLUB, which
increased the maximal time the slab_mutex can be held.
To prevent that from happening, let's use a special ordered single
threaded workqueue for kmem cache creation. This shouldn't introduce
any functional changes regarding how kmem caches are created, as the
work function holds the global slab_mutex during its whole runtime
anyway, making it impossible to run more than one work at a time. By
using a single threaded workqueue, we just avoid creating a thread per
each work. Ordering is required to avoid a situation when a cgroup's
work is put off indefinitely because there are other cgroups to serve,
in other words to guarantee fairness.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=172981 Link: http://lkml.kernel.org/r/20161004131417.GC1862@esperanza Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deepa Dinamani [Tue, 13 Dec 2016 00:41:26 +0000 (16:41 -0800)]
ocfs2: replace CURRENT_TIME macro
CURRENT_TIME is not y2038 safe.
Use y2038 safe ktime_get_real_seconds() here for timestamps. struct
heartbeat_block's hb_seq and deletetion time are already 64 bits wide
and accommodate times beyond y2038.
Also use y2038 safe ktime_get_real_ts64() for on disk inode timestamps.
These are also wide enough to accommodate time64_t.
Link: http://lkml.kernel.org/r/1475365298-29236-1-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deepa Dinamani [Tue, 13 Dec 2016 00:41:23 +0000 (16:41 -0800)]
ocfs2: use time64_t to represent orphan scan times
struct timespec is not y2038 safe. Use time64_t which is y2038 safe to
represent orphan scan times. time64_t is sufficient here as only the
seconds delta times are relevant.
Also use appropriate time functions that return time in time64_t format.
Time functions now return monotonic time instead of real time as only
delta scan times are relevant and these values are not persistent across
reboots.
The format string for the debug print is still using long as this is
only the time elapsed since the last scan and long is sufficient to
represent this value.
Link: http://lkml.kernel.org/r/1475365138-20567-1-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ashish Samant [Tue, 13 Dec 2016 00:41:20 +0000 (16:41 -0800)]
ocfs2: fix double put of recount tree in ocfs2_lock_refcount_tree()
In ocfs2_lock_refcount_tree, if ocfs2_read_refcount_block() returns an
error, we do ocfs2_refcount_tree_put twice (once in
ocfs2_unlock_refcount_tree and once outside it), thereby reducing the
refcount of the refcount tree twice, but we dont delete the tree in this
case. This will make refcnt of the tree = 0 and the
ocfs2_refcount_tree_put will eventually call ocfs2_mark_lockres_freeing,
setting OCFS2_LOCK_FREEING for the refcount_tree->rf_lockres.
The error returned by ocfs2_read_refcount_block is propagated all the
way back and for next iteration of write, ocfs2_lock_refcount_tree gets
the same tree back from ocfs2_get_refcount_tree because we havent
deleted the tree. Now we have the same tree, but OCFS2_LOCK_FREEING is
set for rf_lockres and eventually, when _ocfs2_lock_refcount_tree is
called in this iteration, BUG_ON( __ocfs2_cluster_lock:1395 ERROR:
Cluster lock called on freeing lockres T00000000000000000386019775b08d!
flags 0x81) is triggerred.
Call stack:
(loop16,11155,0):ocfs2_lock_refcount_tree:482 ERROR: status = -5
(loop16,11155,0):ocfs2_refcount_cow_hunk:3497 ERROR: status = -5
(loop16,11155,0):ocfs2_refcount_cow:3560 ERROR: status = -5
(loop16,11155,0):ocfs2_prepare_inode_for_refcount:2111 ERROR: status = -5
(loop16,11155,0):ocfs2_prepare_inode_for_write:2190 ERROR: status = -5
(loop16,11155,0):ocfs2_file_write_iter:2331 ERROR: status = -5
(loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: bug expression:
lockres->l_flags & OCFS2_LOCK_FREEING
(loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: Cluster lock called on
freeing lockres T00000000000000000386019775b08d! flags 0x81
piaojun [Tue, 13 Dec 2016 00:41:17 +0000 (16:41 -0800)]
ocfs2: clean up unused 'page' parameter in ocfs2_write_end_nolock()
'page' parameter in ocfs2_write_end_nolock() is never used.
Link: http://lkml.kernel.org/r/582FD91A.5000902@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
piaojun [Tue, 13 Dec 2016 00:41:14 +0000 (16:41 -0800)]
ocfs2/dlm: clean up deadcode in dlm_master_request_handler()
When 'dispatch_assert' is set, 'response' must be DLM_MASTER_RESP_YES,
and 'res' won't be null, so execution can't reach these two branch.
Link: http://lkml.kernel.org/r/58174C91.3040004@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Joseph Qi Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
piaojun [Tue, 13 Dec 2016 00:41:08 +0000 (16:41 -0800)]
ocfs2/dlm: clean up useless BUG_ON default case in dlm_finalize_reco_handler()
The value of 'stage' must be between 1 and 2, so the switch can't reach
the default case.
Link: http://lkml.kernel.org/r/57FB5EB2.7050002@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sudip Mukherjee [Tue, 13 Dec 2016 00:40:57 +0000 (16:40 -0800)]
m32r: fix build warning
While building m32r defconfig we got warnings:
arch/m32r/platforms/m32700ut/setup.c:249:24: warning: 'm32700ut_lcdpld_irq_type' defined but not used [-Wunused-variable]
m32700ut_lcdpld_irq_type is only used when CONFIG_USB is enabled.
Modify the code to declare the related variables and functions only when
CONFIG_USB is enabled.
Sudip Mukherjee [Tue, 13 Dec 2016 00:40:54 +0000 (16:40 -0800)]
m32r: add simple dma
Some builds of m32r were failing as it tried to build few drivers which
needed dma but m32r is not having dma support. Objections were raised
when it was tried to make those drivers depend on HAS_DMA. So the next
best thing is to add dma support to m32r. dma_noop is a very simple dma
with 1:1 memory mapping.
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