On 12/20/2016 02:01 PM, Michal Hocko wrote: > From: Michal Hocko <[email protected]> > > 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 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=withdrawn retries=0 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 was withdrawn.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. > > Changes since v1 > - fix compaction_result into highlevel constants translation as per > Vlastimil > > Signed-off-by: Michal Hocko <[email protected]> > Acked-by: Vlastimil Babka <[email protected]>
Hmm I've noticed that I didn't suggest the following below here, although I did for the vmscan tracepoints now. How about adding this -fix for consistency? --------8<-------- From: Vlastimil Babka <[email protected]> Date: Wed, 4 Jan 2017 11:44:09 +0100 Subject: [PATCH] oom, trace: add compaction retry tracepoint-fix Let's print the compaction priorities lower-case and without prefix for consistency. Also indent fix in compact_result_to_feedback(). Signed-off-by: Vlastimil Babka <[email protected]> --- include/trace/events/mmflags.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index aa4caa6914a9..e4c3a0febcce 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -195,7 +195,7 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ #define compact_result_to_feedback(result) \ ({ \ - enum compact_result __result = result; \ + enum compact_result __result = result; \ (compaction_failed(__result)) ? COMPACTION_FAILED : \ (compaction_withdrawn(__result)) ? COMPACTION_WITHDRAWN : COMPACTION_PROGRESS; \ }) @@ -206,9 +206,9 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ EMe(COMPACTION_PROGRESS, "progress") #define COMPACTION_PRIORITY \ - EM(COMPACT_PRIO_SYNC_FULL, "COMPACT_PRIO_SYNC_FULL") \ - EM(COMPACT_PRIO_SYNC_LIGHT, "COMPACT_PRIO_SYNC_LIGHT") \ - EMe(COMPACT_PRIO_ASYNC, "COMPACT_PRIO_ASYNC") + EM(COMPACT_PRIO_SYNC_FULL, "sync_full") \ + EM(COMPACT_PRIO_SYNC_LIGHT, "sync_light") \ + EMe(COMPACT_PRIO_ASYNC, "async") #else #define COMPACTION_STATUS #define COMPACTION_PRIORITY -- 2.11.0
