linux-stable/include/trace/events/vmscan.h
Mel Gorman 1b4e3f26f9 mm: vmscan: Reduce throttling due to a failure to make progress
Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar
problems due to reclaim throttling for excessive lengths of time.  In
Alexey's case, a memory hog that should go OOM quickly stalls for
several minutes before stalling.  In Mike and Darrick's cases, a small
memcg environment stalled excessively even though the system had enough
memory overall.

Commit 69392a403f ("mm/vmscan: throttle reclaim when no progress is
being made") introduced the problem although commit a19594ca4a
("mm/vmscan: increase the timeout if page reclaim is not making
progress") made it worse.  Systems at or near an OOM state that cannot
be recovered must reach OOM quickly and memcg should kill tasks if a
memcg is near OOM.

To address this, only stall for the first zone in the zonelist, reduce
the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if
the scan control nr_reclaimed is 0, kswapd is still active and there
were excessive pages pending for writeback.  If kswapd has stopped
reclaiming due to excessive failures, do not stall at all so that OOM
triggers relatively quickly.  Similarly, if an LRU is simply congested,
only lightly throttle similar to NOPROGRESS.

Alexey's original case was the most straight forward

	for i in {1..3}; do tail /dev/zero; done

On vanilla 5.16-rc1, this test stalled heavily, after the patch the test
completes in a few seconds similar to 5.15.

Alexey's second test case added watching a youtube video while tail runs
10 times.  On 5.15, playback only jitters slightly, 5.16-rc1 stalls a
lot with lots of frames missing and numerous audio glitches.  With this
patch applies, the video plays similarly to 5.15.

[lkp@intel.com: Fix W=1 build warning]

Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de
Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv
Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net
Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net
Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/
Reported-and-tested-by: Alexey Avramov <hakavlad@inbox.lv>
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info>
Fixes: 69392a403f ("mm/vmscan: throttle reclaim when no progress is being made")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-31 11:17:07 -08:00

500 lines
12 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM vmscan
#if !defined(_TRACE_VMSCAN_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_VMSCAN_H
#include <linux/types.h>
#include <linux/tracepoint.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <trace/events/mmflags.h>
#define RECLAIM_WB_ANON 0x0001u
#define RECLAIM_WB_FILE 0x0002u
#define RECLAIM_WB_MIXED 0x0010u
#define RECLAIM_WB_SYNC 0x0004u /* Unused, all reclaim async */
#define RECLAIM_WB_ASYNC 0x0008u
#define RECLAIM_WB_LRU (RECLAIM_WB_ANON|RECLAIM_WB_FILE)
#define show_reclaim_flags(flags) \
(flags) ? __print_flags(flags, "|", \
{RECLAIM_WB_ANON, "RECLAIM_WB_ANON"}, \
{RECLAIM_WB_FILE, "RECLAIM_WB_FILE"}, \
{RECLAIM_WB_MIXED, "RECLAIM_WB_MIXED"}, \
{RECLAIM_WB_SYNC, "RECLAIM_WB_SYNC"}, \
{RECLAIM_WB_ASYNC, "RECLAIM_WB_ASYNC"} \
) : "RECLAIM_WB_NONE"
#define _VMSCAN_THROTTLE_WRITEBACK (1 << VMSCAN_THROTTLE_WRITEBACK)
#define _VMSCAN_THROTTLE_ISOLATED (1 << VMSCAN_THROTTLE_ISOLATED)
#define _VMSCAN_THROTTLE_NOPROGRESS (1 << VMSCAN_THROTTLE_NOPROGRESS)
#define _VMSCAN_THROTTLE_CONGESTED (1 << VMSCAN_THROTTLE_CONGESTED)
#define show_throttle_flags(flags) \
(flags) ? __print_flags(flags, "|", \
{_VMSCAN_THROTTLE_WRITEBACK, "VMSCAN_THROTTLE_WRITEBACK"}, \
{_VMSCAN_THROTTLE_ISOLATED, "VMSCAN_THROTTLE_ISOLATED"}, \
{_VMSCAN_THROTTLE_NOPROGRESS, "VMSCAN_THROTTLE_NOPROGRESS"}, \
{_VMSCAN_THROTTLE_CONGESTED, "VMSCAN_THROTTLE_CONGESTED"} \
) : "VMSCAN_THROTTLE_NONE"
#define trace_reclaim_flags(file) ( \
(file ? RECLAIM_WB_FILE : RECLAIM_WB_ANON) | \
(RECLAIM_WB_ASYNC) \
)
TRACE_EVENT(mm_vmscan_kswapd_sleep,
TP_PROTO(int nid),
TP_ARGS(nid),
TP_STRUCT__entry(
__field( int, nid )
),
TP_fast_assign(
__entry->nid = nid;
),
TP_printk("nid=%d", __entry->nid)
);
TRACE_EVENT(mm_vmscan_kswapd_wake,
TP_PROTO(int nid, int zid, int order),
TP_ARGS(nid, zid, order),
TP_STRUCT__entry(
__field( int, nid )
__field( int, zid )
__field( int, order )
),
TP_fast_assign(
__entry->nid = nid;
__entry->zid = zid;
__entry->order = order;
),
TP_printk("nid=%d order=%d",
__entry->nid,
__entry->order)
);
TRACE_EVENT(mm_vmscan_wakeup_kswapd,
TP_PROTO(int nid, int zid, int order, gfp_t gfp_flags),
TP_ARGS(nid, zid, order, gfp_flags),
TP_STRUCT__entry(
__field( int, nid )
__field( int, zid )
__field( int, order )
__field( gfp_t, gfp_flags )
),
TP_fast_assign(
__entry->nid = nid;
__entry->zid = zid;
__entry->order = order;
__entry->gfp_flags = gfp_flags;
),
TP_printk("nid=%d order=%d gfp_flags=%s",
__entry->nid,
__entry->order,
show_gfp_flags(__entry->gfp_flags))
);
DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,
TP_PROTO(int order, gfp_t gfp_flags),
TP_ARGS(order, gfp_flags),
TP_STRUCT__entry(
__field( int, order )
__field( gfp_t, gfp_flags )
),
TP_fast_assign(
__entry->order = order;
__entry->gfp_flags = gfp_flags;
),
TP_printk("order=%d gfp_flags=%s",
__entry->order,
show_gfp_flags(__entry->gfp_flags))
);
DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_direct_reclaim_begin,
TP_PROTO(int order, gfp_t gfp_flags),
TP_ARGS(order, gfp_flags)
);
#ifdef CONFIG_MEMCG
DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_memcg_reclaim_begin,
TP_PROTO(int order, gfp_t gfp_flags),
TP_ARGS(order, gfp_flags)
);
DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_memcg_softlimit_reclaim_begin,
TP_PROTO(int order, gfp_t gfp_flags),
TP_ARGS(order, gfp_flags)
);
#endif /* CONFIG_MEMCG */
DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_end_template,
TP_PROTO(unsigned long nr_reclaimed),
TP_ARGS(nr_reclaimed),
TP_STRUCT__entry(
__field( unsigned long, nr_reclaimed )
),
TP_fast_assign(
__entry->nr_reclaimed = nr_reclaimed;
),
TP_printk("nr_reclaimed=%lu", __entry->nr_reclaimed)
);
DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_direct_reclaim_end,
TP_PROTO(unsigned long nr_reclaimed),
TP_ARGS(nr_reclaimed)
);
#ifdef CONFIG_MEMCG
DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_memcg_reclaim_end,
TP_PROTO(unsigned long nr_reclaimed),
TP_ARGS(nr_reclaimed)
);
DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_memcg_softlimit_reclaim_end,
TP_PROTO(unsigned long nr_reclaimed),
TP_ARGS(nr_reclaimed)
);
#endif /* CONFIG_MEMCG */
TRACE_EVENT(mm_shrink_slab_start,
TP_PROTO(struct shrinker *shr, struct shrink_control *sc,
long nr_objects_to_shrink, unsigned long cache_items,
unsigned long long delta, unsigned long total_scan,
int priority),
TP_ARGS(shr, sc, nr_objects_to_shrink, cache_items, delta, total_scan,
priority),
TP_STRUCT__entry(
__field(struct shrinker *, shr)
__field(void *, shrink)
__field(int, nid)
__field(long, nr_objects_to_shrink)
__field(gfp_t, gfp_flags)
__field(unsigned long, cache_items)
__field(unsigned long long, delta)
__field(unsigned long, total_scan)
__field(int, priority)
),
TP_fast_assign(
__entry->shr = shr;
__entry->shrink = shr->scan_objects;
__entry->nid = sc->nid;
__entry->nr_objects_to_shrink = nr_objects_to_shrink;
__entry->gfp_flags = sc->gfp_mask;
__entry->cache_items = cache_items;
__entry->delta = delta;
__entry->total_scan = total_scan;
__entry->priority = priority;
),
TP_printk("%pS %p: nid: %d objects to shrink %ld gfp_flags %s cache items %ld delta %lld total_scan %ld priority %d",
__entry->shrink,
__entry->shr,
__entry->nid,
__entry->nr_objects_to_shrink,
show_gfp_flags(__entry->gfp_flags),
__entry->cache_items,
__entry->delta,
__entry->total_scan,
__entry->priority)
);
TRACE_EVENT(mm_shrink_slab_end,
TP_PROTO(struct shrinker *shr, int nid, int shrinker_retval,
long unused_scan_cnt, long new_scan_cnt, long total_scan),
TP_ARGS(shr, nid, shrinker_retval, unused_scan_cnt, new_scan_cnt,
total_scan),
TP_STRUCT__entry(
__field(struct shrinker *, shr)
__field(int, nid)
__field(void *, shrink)
__field(long, unused_scan)
__field(long, new_scan)
__field(int, retval)
__field(long, total_scan)
),
TP_fast_assign(
__entry->shr = shr;
__entry->nid = nid;
__entry->shrink = shr->scan_objects;
__entry->unused_scan = unused_scan_cnt;
__entry->new_scan = new_scan_cnt;
__entry->retval = shrinker_retval;
__entry->total_scan = total_scan;
),
TP_printk("%pS %p: nid: %d unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d",
__entry->shrink,
__entry->shr,
__entry->nid,
__entry->unused_scan,
__entry->new_scan,
__entry->total_scan,
__entry->retval)
);
TRACE_EVENT(mm_vmscan_lru_isolate,
TP_PROTO(int highest_zoneidx,
int order,
unsigned long nr_requested,
unsigned long nr_scanned,
unsigned long nr_skipped,
unsigned long nr_taken,
isolate_mode_t isolate_mode,
int lru),
TP_ARGS(highest_zoneidx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, isolate_mode, lru),
TP_STRUCT__entry(
__field(int, highest_zoneidx)
__field(int, order)
__field(unsigned long, nr_requested)
__field(unsigned long, nr_scanned)
__field(unsigned long, nr_skipped)
__field(unsigned long, nr_taken)
__field(isolate_mode_t, isolate_mode)
__field(int, lru)
),
TP_fast_assign(
__entry->highest_zoneidx = highest_zoneidx;
__entry->order = order;
__entry->nr_requested = nr_requested;
__entry->nr_scanned = nr_scanned;
__entry->nr_skipped = nr_skipped;
__entry->nr_taken = nr_taken;
__entry->isolate_mode = isolate_mode;
__entry->lru = lru;
),
/*
* classzone is previous name of the highest_zoneidx.
* Reason not to change it is the ABI requirement of the tracepoint.
*/
TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_skipped=%lu nr_taken=%lu lru=%s",
__entry->isolate_mode,
__entry->highest_zoneidx,
__entry->order,
__entry->nr_requested,
__entry->nr_scanned,
__entry->nr_skipped,
__entry->nr_taken,
__print_symbolic(__entry->lru, LRU_NAMES))
);
TRACE_EVENT(mm_vmscan_writepage,
TP_PROTO(struct page *page),
TP_ARGS(page),
TP_STRUCT__entry(
__field(unsigned long, pfn)
__field(int, reclaim_flags)
),
TP_fast_assign(
__entry->pfn = page_to_pfn(page);
__entry->reclaim_flags = trace_reclaim_flags(
page_is_file_lru(page));
),
TP_printk("page=%p pfn=0x%lx flags=%s",
pfn_to_page(__entry->pfn),
__entry->pfn,
show_reclaim_flags(__entry->reclaim_flags))
);
TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
TP_PROTO(int nid,
unsigned long nr_scanned, unsigned long nr_reclaimed,
struct reclaim_stat *stat, int priority, int file),
TP_ARGS(nid, nr_scanned, nr_reclaimed, stat, priority, file),
TP_STRUCT__entry(
__field(int, nid)
__field(unsigned long, nr_scanned)
__field(unsigned long, nr_reclaimed)
__field(unsigned long, nr_dirty)
__field(unsigned long, nr_writeback)
__field(unsigned long, nr_congested)
__field(unsigned long, nr_immediate)
__field(unsigned int, nr_activate0)
__field(unsigned int, nr_activate1)
__field(unsigned long, nr_ref_keep)
__field(unsigned long, nr_unmap_fail)
__field(int, priority)
__field(int, reclaim_flags)
),
TP_fast_assign(
__entry->nid = nid;
__entry->nr_scanned = nr_scanned;
__entry->nr_reclaimed = nr_reclaimed;
__entry->nr_dirty = stat->nr_dirty;
__entry->nr_writeback = stat->nr_writeback;
__entry->nr_congested = stat->nr_congested;
__entry->nr_immediate = stat->nr_immediate;
__entry->nr_activate0 = stat->nr_activate[0];
__entry->nr_activate1 = stat->nr_activate[1];
__entry->nr_ref_keep = stat->nr_ref_keep;
__entry->nr_unmap_fail = stat->nr_unmap_fail;
__entry->priority = priority;
__entry->reclaim_flags = trace_reclaim_flags(file);
),
TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d flags=%s",
__entry->nid,
__entry->nr_scanned, __entry->nr_reclaimed,
__entry->nr_dirty, __entry->nr_writeback,
__entry->nr_congested, __entry->nr_immediate,
__entry->nr_activate0, __entry->nr_activate1,
__entry->nr_ref_keep, __entry->nr_unmap_fail,
__entry->priority,
show_reclaim_flags(__entry->reclaim_flags))
);
TRACE_EVENT(mm_vmscan_lru_shrink_active,
TP_PROTO(int nid, unsigned long nr_taken,
unsigned long nr_active, unsigned long nr_deactivated,
unsigned long nr_referenced, int priority, int file),
TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, priority, file),
TP_STRUCT__entry(
__field(int, nid)
__field(unsigned long, nr_taken)
__field(unsigned long, nr_active)
__field(unsigned long, nr_deactivated)
__field(unsigned long, nr_referenced)
__field(int, priority)
__field(int, reclaim_flags)
),
TP_fast_assign(
__entry->nid = nid;
__entry->nr_taken = nr_taken;
__entry->nr_active = nr_active;
__entry->nr_deactivated = nr_deactivated;
__entry->nr_referenced = nr_referenced;
__entry->priority = priority;
__entry->reclaim_flags = trace_reclaim_flags(file);
),
TP_printk("nid=%d nr_taken=%ld nr_active=%ld nr_deactivated=%ld nr_referenced=%ld priority=%d flags=%s",
__entry->nid,
__entry->nr_taken,
__entry->nr_active, __entry->nr_deactivated, __entry->nr_referenced,
__entry->priority,
show_reclaim_flags(__entry->reclaim_flags))
);
TRACE_EVENT(mm_vmscan_node_reclaim_begin,
TP_PROTO(int nid, int order, gfp_t gfp_flags),
TP_ARGS(nid, order, gfp_flags),
TP_STRUCT__entry(
__field(int, nid)
__field(int, order)
__field(gfp_t, gfp_flags)
),
TP_fast_assign(
__entry->nid = nid;
__entry->order = order;
__entry->gfp_flags = gfp_flags;
),
TP_printk("nid=%d order=%d gfp_flags=%s",
__entry->nid,
__entry->order,
show_gfp_flags(__entry->gfp_flags))
);
DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_node_reclaim_end,
TP_PROTO(unsigned long nr_reclaimed),
TP_ARGS(nr_reclaimed)
);
TRACE_EVENT(mm_vmscan_throttled,
TP_PROTO(int nid, int usec_timeout, int usec_delayed, int reason),
TP_ARGS(nid, usec_timeout, usec_delayed, reason),
TP_STRUCT__entry(
__field(int, nid)
__field(int, usec_timeout)
__field(int, usec_delayed)
__field(int, reason)
),
TP_fast_assign(
__entry->nid = nid;
__entry->usec_timeout = usec_timeout;
__entry->usec_delayed = usec_delayed;
__entry->reason = 1U << reason;
),
TP_printk("nid=%d usec_timeout=%d usect_delayed=%d reason=%s",
__entry->nid,
__entry->usec_timeout,
__entry->usec_delayed,
show_throttle_flags(__entry->reason))
);
#endif /* _TRACE_VMSCAN_H */
/* This part must be outside protection */
#include <trace/define_trace.h>