Re: Additional LWLOCK_STATS statistics

On 09/15/2015 03:51 PM, Jesper Pedersen wrote:
>> It
>> would be nice to get a better sense of how *long* we block on various
>> locks. It's hard to tell whether some other lock might be have fewer
>> blocking events but for a much longer average duration.
>>
>

I did a run with the attached patch, recording the time from
LWLockQueueSelf() until the lock is required.

Doing block_time / block_count basically only shows "main 0" -- its
called "unassigned:0"; it also shows up in the max exclusive report.
Where it is coming from is another question, since it shouldn't be in use.

Due to the overhead of gettimeofday() I think that _v1 is better to
consider.

Best regards,
Jesper