Re: Add per-backend lock statistics

Hi,

On Thu, Jun 25, 2026 at 11:40:19PM +0800, Rui Zhao wrote:
> Hi Bertrand,
>
> I reviewed and tested v2; it builds cleanly. The implementation closely
> mirrors the existing per-backend IO/WAL stats (same flush path, struct
> layout, and backend-type guard), and the hot path is untouched: the
> per-backend counters piggyback on the existing global counting points
> (pgstat_count_lock_waits / pgstat_count_lock_fastpath_exceeded), so they
> only fire where pg_stat_lock already counts -- fastpath_exceeded when the
> fast-path slot limit is exceeded, and waits/wait_time only after a wait
> longer than deadlock_timeout.

Thanks for the review. Attached is a rebase due to c776550e466 and making
use of the same changes.

> One tiny nit: in pgstat_count_backend_lock_waits() and
> pgstat_count_backend_lock_fastpath_exceeded(), the Assert() is directly
> followed by the counter update. A blank line after the Assert() would read
> a bit better and is the more usual style in this code.

Yeah, done in the attached.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com