--- /dev/null
+From 3168fc7faf603da9d523c9dffbec6fee5b1a8a04 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Fabian=20Gr=C3=BCnbichler?= <f.gruenbichler@proxmox.com>
+Date: Wed, 4 Jan 2017 11:29:00 +0100
+Subject: [PATCH 1/2] Revert "mm: throttle on IO only when there are too many
+ dirty and writeback pages"
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This reverts commit 57e9ef475661f46769cad6c0ed9a13f0cec1dbd8.
+
+Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
+---
+ mm/backing-dev.c | 20 +++++++++++++++++---
+ mm/page_alloc.c | 41 ++++-------------------------------------
+ 2 files changed, 21 insertions(+), 40 deletions(-)
+
+diff --git a/mm/backing-dev.c b/mm/backing-dev.c
+index a1aef87..9ef80bf 100644
+--- a/mm/backing-dev.c
++++ b/mm/backing-dev.c
+@@ -976,8 +976,9 @@ EXPORT_SYMBOL(congestion_wait);
+ * jiffies for either a BDI to exit congestion of the given @sync queue
+ * or a write to complete.
+ *
+- * In the absence of zone congestion, cond_resched() is called to yield
+- * the processor if necessary but otherwise does not sleep.
++ * In the absence of zone congestion, a short sleep or a cond_resched is
++ * performed to yield the processor and to allow other subsystems to make
++ * a forward progress.
+ *
+ * The return value is 0 if the sleep is for the full timeout. Otherwise,
+ * it is the number of jiffies that were still remaining when the function
+@@ -997,7 +998,20 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout)
+ */
+ if (atomic_read(&nr_wb_congested[sync]) == 0 ||
+ !test_bit(ZONE_CONGESTED, &zone->flags)) {
+- cond_resched();
++
++ /*
++ * Memory allocation/reclaim might be called from a WQ
++ * context and the current implementation of the WQ
++ * concurrency control doesn't recognize that a particular
++ * WQ is congested if the worker thread is looping without
++ * ever sleeping. Therefore we have to do a short sleep
++ * here rather than calling cond_resched().
++ */
++ if (current->flags & PF_WQ_WORKER)
++ schedule_timeout_uninterruptible(1);
++ else
++ cond_resched();
++
+ /* In case we scheduled, work out time remaining */
+ ret = timeout - (jiffies - start);
+ if (ret < 0)
+diff --git a/mm/page_alloc.c b/mm/page_alloc.c
+index aadbd7e..f13b503 100644
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -3038,9 +3038,8 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+ ac->nodemask) {
+ unsigned long available;
+- unsigned long reclaimable;
+
+- available = reclaimable = zone_reclaimable_pages(zone);
++ available = zone_reclaimable_pages(zone);
+ available -= DIV_ROUND_UP(no_progress_loops * available,
+ MAX_RECLAIM_RETRIES);
+ available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
+@@ -3050,41 +3049,9 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
+ * available?
+ */
+ if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
+- ac->classzone_idx, alloc_flags, available)) {
+- /*
+- * If we didn't make any progress and have a lot of
+- * dirty + writeback pages then we should wait for
+- * an IO to complete to slow down the reclaim and
+- * prevent from pre mature OOM
+- */
+- if (!did_some_progress) {
+- unsigned long writeback;
+- unsigned long dirty;
+-
+- writeback = zone_page_state_snapshot(zone,
+- NR_WRITEBACK);
+- dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY);
+-
+- if (2*(writeback + dirty) > reclaimable) {
+- congestion_wait(BLK_RW_ASYNC, HZ/10);
+- return true;
+- }
+- }
+-
+- /*
+- * Memory allocation/reclaim might be called from a WQ
+- * context and the current implementation of the WQ
+- * concurrency control doesn't recognize that
+- * a particular WQ is congested if the worker thread is
+- * looping without ever sleeping. Therefore we have to
+- * do a short sleep here rather than calling
+- * cond_resched().
+- */
+- if (current->flags & PF_WQ_WORKER)
+- schedule_timeout_uninterruptible(1);
+- else
+- cond_resched();
+-
++ ac->high_zoneidx, alloc_flags, available)) {
++ /* Wait for some write requests to complete then retry */
++ wait_iff_congested(zone, BLK_RW_ASYNC, HZ/50);
+ return true;
+ }
+ }
+--
+2.1.4
+
--- /dev/null
+From 6e2588df3dc3d1704eae939ed9c9425000f48069 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Fabian=20Gr=C3=BCnbichler?= <f.gruenbichler@proxmox.com>
+Date: Wed, 4 Jan 2017 11:29:26 +0100
+Subject: [PATCH 2/2] Revert "mm, oom: rework oom detection"
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This reverts commit c630ec12d831521b0566481eb56d7257b051911e.
+
+Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
+---
+ include/linux/swap.h | 1 -
+ mm/page_alloc.c | 100 +++++----------------------------------------------
+ mm/vmscan.c | 25 ++++++++++---
+ 3 files changed, 29 insertions(+), 97 deletions(-)
+
+diff --git a/include/linux/swap.h b/include/linux/swap.h
+index 1498c5a..d8ca2ea 100644
+--- a/include/linux/swap.h
++++ b/include/linux/swap.h
+@@ -318,7 +318,6 @@ extern void lru_cache_add_active_or_unevictable(struct page *page,
+ struct vm_area_struct *vma);
+
+ /* linux/mm/vmscan.c */
+-extern unsigned long zone_reclaimable_pages(struct zone *zone);
+ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
+ gfp_t gfp_mask, nodemask_t *mask);
+ extern int __isolate_lru_page(struct page *page, isolate_mode_t mode);
+diff --git a/mm/page_alloc.c b/mm/page_alloc.c
+index f13b503..56319cf 100644
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -2988,77 +2988,6 @@ static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
+ return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
+ }
+
+-/*
+- * Maximum number of reclaim retries without any progress before OOM killer
+- * is consider as the only way to move forward.
+- */
+-#define MAX_RECLAIM_RETRIES 16
+-
+-/*
+- * Checks whether it makes sense to retry the reclaim to make a forward progress
+- * for the given allocation request.
+- * The reclaim feedback represented by did_some_progress (any progress during
+- * the last reclaim round), pages_reclaimed (cumulative number of reclaimed
+- * pages) and no_progress_loops (number of reclaim rounds without any progress
+- * in a row) is considered as well as the reclaimable pages on the applicable
+- * zone list (with a backoff mechanism which is a function of no_progress_loops).
+- *
+- * Returns true if a retry is viable or false to enter the oom path.
+- */
+-static inline bool
+-should_reclaim_retry(gfp_t gfp_mask, unsigned order,
+- struct alloc_context *ac, int alloc_flags,
+- bool did_some_progress, unsigned long pages_reclaimed,
+- int no_progress_loops)
+-{
+- struct zone *zone;
+- struct zoneref *z;
+-
+- /*
+- * Make sure we converge to OOM if we cannot make any progress
+- * several times in the row.
+- */
+- if (no_progress_loops > MAX_RECLAIM_RETRIES)
+- return false;
+-
+- if (order > PAGE_ALLOC_COSTLY_ORDER) {
+- if (pages_reclaimed >= (1<<order))
+- return false;
+-
+- if (did_some_progress)
+- return true;
+- }
+-
+- /*
+- * Keep reclaiming pages while there is a chance this will lead somewhere.
+- * If none of the target zones can satisfy our allocation request even
+- * if all reclaimable pages are considered then we are screwed and have
+- * to go OOM.
+- */
+- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+- ac->nodemask) {
+- unsigned long available;
+-
+- available = zone_reclaimable_pages(zone);
+- available -= DIV_ROUND_UP(no_progress_loops * available,
+- MAX_RECLAIM_RETRIES);
+- available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
+-
+- /*
+- * Would the allocation succeed if we reclaimed the whole
+- * available?
+- */
+- if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
+- ac->high_zoneidx, alloc_flags, available)) {
+- /* Wait for some write requests to complete then retry */
+- wait_iff_congested(zone, BLK_RW_ASYNC, HZ/50);
+- return true;
+- }
+- }
+-
+- return false;
+-}
+-
+ static inline struct page *
+ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
+ struct alloc_context *ac)
+@@ -3071,7 +3000,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
+ enum migrate_mode migration_mode = MIGRATE_ASYNC;
+ bool deferred_compaction = false;
+ int contended_compaction = COMPACT_CONTENDED_NONE;
+- int no_progress_loops = 0;
+
+ /*
+ * In the slowpath, we sanity check order to avoid ever trying to
+@@ -3223,24 +3151,14 @@ retry:
+ if (gfp_mask & __GFP_NORETRY)
+ goto noretry;
+
+- /*
+- * Do not retry costly high order allocations unless they are
+- * __GFP_REPEAT
+- */
+- if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
+- goto noretry;
+-
+- if (did_some_progress) {
+- no_progress_loops = 0;
+- pages_reclaimed += did_some_progress;
+- } else {
+- no_progress_loops++;
+- }
+-
+- if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
+- did_some_progress > 0, pages_reclaimed,
+- no_progress_loops))
++ /* Keep reclaiming pages as long as there is reasonable progress */
++ pages_reclaimed += did_some_progress;
++ if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
++ ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
++ /* Wait for some write requests to complete then retry */
++ wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
+ goto retry;
++ }
+
+ /* Reclaim has failed us, start killing things */
+ page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
+@@ -3248,10 +3166,8 @@ retry:
+ goto got_pg;
+
+ /* Retry as long as the OOM killer is making progress */
+- if (did_some_progress) {
+- no_progress_loops = 0;
++ if (did_some_progress)
+ goto retry;
+- }
+
+ noretry:
+ /*
+diff --git a/mm/vmscan.c b/mm/vmscan.c
+index 56f902d..3597160 100644
+--- a/mm/vmscan.c
++++ b/mm/vmscan.c
+@@ -192,7 +192,7 @@ static bool sane_reclaim(struct scan_control *sc)
+ }
+ #endif
+
+-unsigned long zone_reclaimable_pages(struct zone *zone)
++static unsigned long zone_reclaimable_pages(struct zone *zone)
+ {
+ unsigned long nr;
+
+@@ -2492,8 +2492,10 @@ static inline bool compaction_ready(struct zone *zone, int order)
+ *
+ * If a zone is deemed to be full of pinned pages then just give it a light
+ * scan then give up on it.
++ *
++ * Returns true if a zone was reclaimable.
+ */
+-static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
++static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+ {
+ struct zoneref *z;
+ struct zone *zone;
+@@ -2501,6 +2503,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+ unsigned long nr_soft_scanned;
+ gfp_t orig_mask;
+ enum zone_type requested_highidx = gfp_zone(sc->gfp_mask);
++ bool reclaimable = false;
+
+ /*
+ * If the number of buffer_heads in the machine exceeds the maximum
+@@ -2565,10 +2568,17 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+ &nr_soft_scanned);
+ sc->nr_reclaimed += nr_soft_reclaimed;
+ sc->nr_scanned += nr_soft_scanned;
++ if (nr_soft_reclaimed)
++ reclaimable = true;
+ /* need some check for avoid more shrink_zone() */
+ }
+
+- shrink_zone(zone, sc, zone_idx(zone) == classzone_idx);
++ if (shrink_zone(zone, sc, zone_idx(zone) == classzone_idx))
++ reclaimable = true;
++
++ if (global_reclaim(sc) &&
++ !reclaimable && zone_reclaimable(zone))
++ reclaimable = true;
+ }
+
+ /*
+@@ -2576,6 +2586,8 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+ * promoted it to __GFP_HIGHMEM.
+ */
+ sc->gfp_mask = orig_mask;
++
++ return reclaimable;
+ }
+
+ /*
+@@ -2600,6 +2612,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
+ int initial_priority = sc->priority;
+ unsigned long total_scanned = 0;
+ unsigned long writeback_threshold;
++ bool zones_reclaimable;
+ retry:
+ delayacct_freepages_start();
+
+@@ -2610,7 +2623,7 @@ retry:
+ vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
+ sc->priority);
+ sc->nr_scanned = 0;
+- shrink_zones(zonelist, sc);
++ zones_reclaimable = shrink_zones(zonelist, sc);
+
+ total_scanned += sc->nr_scanned;
+ if (sc->nr_reclaimed >= sc->nr_to_reclaim)
+@@ -2657,6 +2670,10 @@ retry:
+ goto retry;
+ }
+
++ /* Any of the zones still reclaimable? Don't OOM. */
++ if (zones_reclaimable)
++ return 1;
++
+ return 0;
+ }
+
+--
+2.1.4
+
projects / pve-kernel-jessie.git / commitdiff