Thread: Re: Remove unused wait_event_info parameter in FileStartReadV()

Hi Bertrand,

> While working on wait events related stuff, I noticed that the wait_event_info
> parameter in FileStartReadV() is unused.
>
> The unused parameter is there since 50cb7505b301, and I think it's ok to just
> remove it (as it is set correctly in pgaio_io_perform_synchronously()).

Any chance we should call pgstat_report_wait_start(wait_event_info)
instead similarly to other functions in fd.c?

-- 
Best regards,
Aleksander Alekseev

Hi Aleksander,

On Fri, Jul 04, 2025 at 01:16:02PM +0300, Aleksander Alekseev wrote:
> Hi Bertrand,
> 
> > While working on wait events related stuff, I noticed that the wait_event_info
> > parameter in FileStartReadV() is unused.
> >
> > The unused parameter is there since 50cb7505b301, and I think it's ok to just
> > remove it (as it is set correctly in pgaio_io_perform_synchronously()).
> 
> Any chance we should call pgstat_report_wait_start(wait_event_info)
> instead similarly to other functions in fd.c?

Thanks for looking at it!

I think that's fine because pgstat_report_wait_start(WAIT_EVENT_DATA_FILE_READ)
is actually called in pgaio_io_perform_synchronously().

We could call also call pgstat_report_wait_start(wait_event_info) prior to the
pgaio_io_start_readv() in FileStartReadV() (as I think you're suggesting) but I
think the closer to pg_preadv() the better.

Regards,

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