Re: Scaling shared buffer eviction

On Thu, Sep 11, 2014 at 6:32 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> Thanks for reviewing, Andres.
>
> On Thu, Sep 11, 2014 at 7:01 AM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:
> >> +static void bgreclaim_quickdie(SIGNAL_ARGS);
> >> +static void BgreclaimSigHupHandler(SIGNAL_ARGS);
> >> +static void ReqShutdownHandler(SIGNAL_ARGS);
> >> +static void bgreclaim_sigusr1_handler(SIGNAL_ARGS);
> >
> > This looks inconsistent.
>
> It's exactly the same as what bgwriter.c does.
>
> > No LWLockReleaseAll(), AbortBufferIO(), ...? Unconvinced that that's a
> > good idea, regardless of it possibly being true today (which I'm not
> > sure about yet).
>
> We really need a more centralized way to handle error cleanup in
> auxiliary processes. The current state of affairs is really pretty
> helter-skelter. But for this patch, I think we should aim to mimic
> the existing style, as ugly as it is. I'm not sure whether Amit's got
> the logic correct, though: I'd agree LWLockReleaseAll(), at a minimum,
> is probably a good idea.

Code related to bgreclaimer logic itself doesn't take any LWLock, do
you suspect the same might be required due to some Signal/Interrupt
handling?

From myside, I have thought about what to keep for error cleanup based
on the working of bgreclaimer. However there is a chance that I have
missed something.

With Regards,
Amit Kapila.
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