path: root/include/uapi/linux/userfaultfd.h
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authorMichal Hocko <mhocko@suse.com>2017-02-22 15:42:03 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-22 16:41:27 -0800
commit65190cff3cc108b72e42cce67ed8b73dbad6b731 (patch)
treec57be762c29b20bba680e11303c890c9b49f605b /include/uapi/linux/userfaultfd.h
parentd379f01de09570e06d84b4b09e5f4951821a1dc8 (diff)
oom, trace: add compaction retry tracepoint
Higher order requests oom debugging is currently quite hard. We do have some compaction points which can tell us how the compaction is operating but there is no trace point to tell us about compaction retry logic. This patch adds a one which will have the following format bash-3126 [001] .... 1498.220001: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=withdrawn retries=0 max_retries=16 should_retry=0 we can see that the order 9 request is not retried even though we are in the highest compaction priority mode becase the last compaction attempt was withdrawn. This means that compaction_zonelist_suitable must have returned false and there is no suitable zone to compact for this request and so no need to retry further. another example would be <...>-3137 [001] .... 81.501689: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=failed retries=0 max_retries=16 should_retry=0 in this case the order-9 compaction failed to find any suitable block. We do not retry anymore because this is a costly request and those do not go below COMPACT_PRIO_SYNC_LIGHT priority. Link: http://lkml.kernel.org/r/20161220130135.15719-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/uapi/linux/userfaultfd.h')
0 files changed, 0 insertions, 0 deletions

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