Horton

Re: SLRU statistics

Ranier Vilela <ranier.vf@gmail.com>

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From: Ranier Vilela <ranier.vf@gmail.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-05-13T20:08:39Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix async.c to not register any SLRU stats counts in the postmaster.

  2. Use proper GetDatum function in pg_stat_get_slru().

  3. Initialize SLRU stats entries to zero.

  4. Remove pg_xact from pg_stat_reset_slru docs

  5. Remove pg_xact entry from SLRU stats

  6. Track SLRU page hits in SimpleLruReadPage_ReadOnly

  7. Fix typo in SLRU stats documentation

  8. Collect statistics about SLRU caches

  9. Simplify and rename some GUC variables, per various recent discussions:

Em qua., 13 de mai. de 2020 às 11:46, Fujii Masao <
masao.fujii@oss.nttdata.com> escreveu:

>
>
> On 2020/05/13 23:26, Tom Lane wrote:
> > Fujii Masao <masao.fujii@oss.nttdata.com> writes:
> >> On 2020/05/13 17:21, Tomas Vondra wrote:
> >>> On Wed, May 13, 2020 at 04:10:30PM +0900, Fujii Masao wrote:
> >>>> Also I found another minor issue; SLRUStats has not been initialized
> to 0
> >>>> and which could update the counters unexpectedly. Attached patch fixes
> >>>> this issue.
> >
> >> Pushed both. Thanks!
> >
> > Why is that necessary?  A static variable is defined by C to start off
> > as zeroes.
>
> Because SLRUStats is not a static variable. No?
>
IMHO, BgWriterStats  have the same problem, shouldn't the same be done?

/* Initialize BgWriterStats to zero */
MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));

/* Initialize SLRU statistics to zero */
memset(&SLRUStats, 0, sizeof(SLRUStats));

regards,
Ranier Vilela