Re: pgsql-server/src backend/storage/buffer/bufmgr ...

Jan Wieck wrote:
> Tom Lane wrote:
>
> > wieck@svr1.postgresql.org (Jan Wieck) writes:
> >>     Added GUC variable bgwriter_flush_method controlling the action
> >>     done by the background writer between writing dirty blocks and
> >>     napping.
> >
> >>     none (default)   no action
> >>     sync             bgwriter calls smgrsync() causing a sync(2)
> >
> > Why would that be useful at all?  I thought the purpose of the bgwriter
> > was to avoid I/O storms, not provoke them.
>
> Calling sync(2) every time the background writer naps means calling it
> every couple hundred milliseconds. That can hardly be called an IO
> storm, it's more like a constant breeze.

I talked to Jan about the idea of sync on every background writer sleep.
He is going to study the issue and report back.

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