Re: Reducing WaitEventSet syscall churn

On Fri, Jul 31, 2020 at 9:42 AM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> On Thu, Jul 30, 2020 at 5:50 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> > I pushed those three patches, but will wait for more discussion on the rest.
>
> And here's a rebase, to make cfbot happy.

And again.

To restate the two goals of the remaining patches:

1. Use FeBeWaitSet for walsender, instead of setting up and tearing
down temporary WaitEventSets all the time.
2. Use the standard WL_EXIT_ON_PM_DEATH flag for FeBeWaitSet, instead
of the special case ereport(FATAL, ... "terminating connection due to
unexpected postmaster exit" ...).

For point 2, the question I am raising is: why should users get a
special FATAL message in some places and not others, for PM death?
However, if people are attached to that behaviour, we could still
achieve goal 1 without goal 2 by handling PM death explicitly in
walsender.c and I'd be happy to post an alternative patch set like
that.