On Fri, Feb 23, 2024 at 7:50 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> On Fri, Feb 23, 2024 at 10:22:32AM +0530, Robert Haas wrote:
> > On Thu, Feb 22, 2024 at 6:25 AM James Coleman <jtc331@gmail.com> wrote:
> > > This is potentially a bit of a wild idea, but I wonder if having some
> > > kind of argument to CHECK_FOR_INTERRUPTS() signifying we're in
> > > "normal" as opposed to "critical" (using that word differently than
> > > the existing critical sections) would be worth it.
> >
> > It's worth considering, but the definition of "normal" vs. "critical"
> > might be hard to pin down. Or, we might end up with a definition that
> > is specific to this particular case and not generalizable to others.
>
> But it doesn't have to be all or nothing right? I mean each call could say
> what the situation is like in their context, like
> CHECK_FOR_INTERRUPTS(GUARANTEE_NO_HEAVYWEIGHT_LOCK | GUARANTEE_WHATEVER), and
> slowly tag calls as needed, similarly to how we add already CFI based on users
> report.
Absolutely. My gut feeling is that it's going to be simpler to pick a
small number of places that are safe and sufficient for this
particular feature and add an extra call there, similar to how we do
vacuum_delay_point(). The reason I think that's likely to be better is
that it will likely require changing only a relatively small number of
places. If we instead start annotating CFIs, well, we've got hundreds
of those. That's a lot more to change, and it also inconveniences
third-party extension authors and people doing back-patching. I'm not
here to say it can't work; I just think it's likely not the easiest
path.
--
Robert Haas
EDB: http://www.enterprisedb.com