Re: Additional LWLOCK_STATS statistics

On Tue, Sep 15, 2015 at 10:27 AM, Jesper Pedersen
<jesper(dot)pedersen(at)redhat(dot)com> wrote:
> Hi,
>
> I have been using the attached patch to look at how each LWLock relates to
> each other in various types of runs.
>
> The patch adds the following fields to a LWLOCK_STATS build:
>
> sh_acquire_max (int):
>
> The maximum shared locks in series for the lock
>
> ex_acquire_max (int):
>
> The maximum exclusive locks in series for the lock
>
> max_waiters (int):
>
> The maximum numbers of waiters
>
> Also attached is a sample report using FlameGraphs from a pgbench run using
>
> -c 80 -j 80 -T 300
>
> See README for additional details.
>
> If there is an interest I'll add the patch to the next CommitFest.
>
> Thanks for considering, and any feedback is most welcomed.

Seems neat, but I can't understand how to read the flame graphs.

--
Robert Haas
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