Re: Move unused buffers to freelist

On Tuesday, July 02, 2013 12:00 AM Robert Haas wrote:
> On Sun, Jun 30, 2013 at 3:24 AM, Amit kapila <amit(dot)kapila(at)huawei(dot)com>
> wrote:
> > Do you think it will be sufficient to just wake bgwriter when the
> buffers in freelist drops
> > below low watermark, how about it's current job of flushing dirty
> buffers?
>
> Well, the only point of flushing dirty buffers in the background
> writer is to make sure that backends can allocate buffers quickly. If
> there are clean buffers already in the freelist, that's not a concern.
> So...
>
> > I mean to ask that if for some scenario where there are sufficient
> buffers in freelist, but most
> > other buffers are dirty, will delaying flush untill number of buffers
> fall below low watermark is okay.
>
> ...I think this is OK, or at least we should assume it's OK until we
> have evidence that it isn't.

Sure, after completing my other review work of Commit Fest, I will devise
the solution
for the suggestions summarized in previous mail and then start a discussion
about same.

With Regards,
Amit Kapila.