Re: per backend I/O statistics

Hi,

On Thu, Jan 16, 2025 at 09:55:10AM +0900, Michael Paquier wrote:
> On Wed, Jan 15, 2025 at 05:20:57PM +0300, Nazir Bilal Yavuz wrote:
> > I think allowing only pgStatPendingContext to have
> > MemoryContextAllowInCriticalSection() is not enough. We need to allow
> > at least pgStatSharedRefContext as well to have
> > MemoryContextAllowInCriticalSection() as it can be allocated too.
> > 
> > '''
> > pgstat_prep_pending_entry() ->
> > pgstat_get_entry_ref() ->
> > pgstat_get_entry_ref_cached() ->
> > MemoryContextAlloc(pgStatSharedRefContext, sizeof(PgStat_EntryRef))
> > '''
> 
> Yep, I was pretty sure that we have a bit more going on.  Last time I
> began digging into the issue I was loading injection_points in
> shared_preload_libraries with stats enabled to see how much I could
> break, and this was one pattern once I've forced the pending part.  I
> didn't get through the whole exercise.

I'll look at it and come back with a proposal as part of [1].

[1]: https://www.postgresql.org/message-id/Z4dRlNuhSQ3hPPv2@paquier.xyz

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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