linux_dsm_epyc7002/include/trace/events/oom.h
Roman Gushchin 422580c3ce mm/oom_kill.c: add tracepoints for oom reaper-related events
During the debugging of the problem described in
https://lkml.org/lkml/2017/5/17/542 and fixed by Tetsuo Handa in
https://lkml.org/lkml/2017/5/19/383 , I've found that the existing debug
output is not really useful to understand issues related to the oom
reaper.

So, I assume, that adding some tracepoints might help with debugging of
similar issues.

Trace the following events:
 1) a process is marked as an oom victim,
 2) a process is added to the oom reaper list,
 3) the oom reaper starts reaping process's mm,
 4) the oom reaper finished reaping,
 5) the oom reaper skips reaping.

How it works in practice? Below is an example which show how the problem
mentioned above can be found: one process is added twice to the
oom_reaper list:

  $ cd /sys/kernel/debug/tracing
  $ echo "oom:mark_victim" > set_event
  $ echo "oom:wake_reaper" >> set_event
  $ echo "oom:skip_task_reaping" >> set_event
  $ echo "oom:start_task_reaping" >> set_event
  $ echo "oom:finish_task_reaping" >> set_event
  $ cat trace_pipe
          allocate-502   [001] ....    91.836405: mark_victim: pid=502
          allocate-502   [001] .N..    91.837356: wake_reaper: pid=502
          allocate-502   [000] .N..    91.871149: wake_reaper: pid=502
        oom_reaper-23    [000] ....    91.871177: start_task_reaping: pid=502
        oom_reaper-23    [000] .N..    91.879511: finish_task_reaping: pid=502
        oom_reaper-23    [000] ....    91.879580: skip_task_reaping: pid=502

Link: http://lkml.kernel.org/r/20170530185231.GA13412@castle
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10 16:32:32 -07:00

195 lines
3.8 KiB
C

#undef TRACE_SYSTEM
#define TRACE_SYSTEM oom
#if !defined(_TRACE_OOM_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_OOM_H
#include <linux/tracepoint.h>
#include <trace/events/mmflags.h>
TRACE_EVENT(oom_score_adj_update,
TP_PROTO(struct task_struct *task),
TP_ARGS(task),
TP_STRUCT__entry(
__field( pid_t, pid)
__array( char, comm, TASK_COMM_LEN )
__field( short, oom_score_adj)
),
TP_fast_assign(
__entry->pid = task->pid;
memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
__entry->oom_score_adj = task->signal->oom_score_adj;
),
TP_printk("pid=%d comm=%s oom_score_adj=%hd",
__entry->pid, __entry->comm, __entry->oom_score_adj)
);
TRACE_EVENT(reclaim_retry_zone,
TP_PROTO(struct zoneref *zoneref,
int order,
unsigned long reclaimable,
unsigned long available,
unsigned long min_wmark,
int no_progress_loops,
bool wmark_check),
TP_ARGS(zoneref, order, reclaimable, available, min_wmark, no_progress_loops, wmark_check),
TP_STRUCT__entry(
__field( int, node)
__field( int, zone_idx)
__field( int, order)
__field( unsigned long, reclaimable)
__field( unsigned long, available)
__field( unsigned long, min_wmark)
__field( int, no_progress_loops)
__field( bool, wmark_check)
),
TP_fast_assign(
__entry->node = zone_to_nid(zoneref->zone);
__entry->zone_idx = zoneref->zone_idx;
__entry->order = order;
__entry->reclaimable = reclaimable;
__entry->available = available;
__entry->min_wmark = min_wmark;
__entry->no_progress_loops = no_progress_loops;
__entry->wmark_check = wmark_check;
),
TP_printk("node=%d zone=%-8s order=%d reclaimable=%lu available=%lu min_wmark=%lu no_progress_loops=%d wmark_check=%d",
__entry->node, __print_symbolic(__entry->zone_idx, ZONE_TYPE),
__entry->order,
__entry->reclaimable, __entry->available, __entry->min_wmark,
__entry->no_progress_loops,
__entry->wmark_check)
);
TRACE_EVENT(mark_victim,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
TRACE_EVENT(wake_reaper,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
TRACE_EVENT(start_task_reaping,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
TRACE_EVENT(finish_task_reaping,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
TRACE_EVENT(skip_task_reaping,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
#ifdef CONFIG_COMPACTION
TRACE_EVENT(compact_retry,
TP_PROTO(int order,
enum compact_priority priority,
enum compact_result result,
int retries,
int max_retries,
bool ret),
TP_ARGS(order, priority, result, retries, max_retries, ret),
TP_STRUCT__entry(
__field( int, order)
__field( int, priority)
__field( int, result)
__field( int, retries)
__field( int, max_retries)
__field( bool, ret)
),
TP_fast_assign(
__entry->order = order;
__entry->priority = priority;
__entry->result = compact_result_to_feedback(result);
__entry->retries = retries;
__entry->max_retries = max_retries;
__entry->ret = ret;
),
TP_printk("order=%d priority=%s compaction_result=%s retries=%d max_retries=%d should_retry=%d",
__entry->order,
__print_symbolic(__entry->priority, COMPACTION_PRIORITY),
__print_symbolic(__entry->result, COMPACTION_FEEDBACK),
__entry->retries, __entry->max_retries,
__entry->ret)
);
#endif /* CONFIG_COMPACTION */
#endif
/* This part must be outside protection */
#include <trace/define_trace.h>