Messages in this thread | | | Date | Wed, 21 Oct 2020 08:42:23 +0800 | From | Leo Yan <> | Subject | Re: [PATCH 2/2] perf lock: Don't free "lock_seq_stat" if read_count isn't zero |
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Hi all,
On Wed, Oct 21, 2020 at 08:26:19AM +0800, Leo Yan wrote: > When execute command "perf lock report", it hits failure and outputs log > as follows: > > perf: builtin-lock.c:623: report_lock_release_event: Assertion `!(seq->read_count < 0)' failed. > Aborted > > This is an imbalance issue. The locking sequence structure > "lock_seq_stat" contains the reader counter and it is used to check if > the locking sequence is balance or not between acquiring and releasing. > > If the tool wrongly frees "lock_seq_stat" when "read_count" isn't zero, > the "read_count" will be reset to zero when allocate a new structure at > the next time; thus it causes the wrong counting for reader and finally > results in imbalance issue. > > To fix this issue, if detects "read_count" is not zero (means still > have read user in the locking sequence), goto the "end" tag to skip > freeing structure "lock_seq_stat".
Please ignore this patch set and directly to review patch set v2; I forgot adding "fixes" tag in this patch, so updated in patch set v2.
Sorry for spamming.
Leo
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