On Wed, Nov 30, 2022 at 7:40 PM Simon Riggs <simon.ri...@enterprisedb.com> wrote: > On Wed, 30 Nov 2022 at 03:50, Thomas Munro <thomas.mu...@gmail.com> wrote: > > I'm just curious, and not suggesting that 60s wakeups are a problem > > for the polar ice caps, but why even time out at all? Are the latch > > protocols involved not reliable enough? At a guess from a quick > > glance, the walwriter's is but maybe the bgwriter could miss a wakeup > > as it races against StrategyGetBuffer(), which means you might stay > > asleep until the *next* buffer allocation, but that's already true I > > think, and a 60s timeout is not much of a defence. > > That sounds reasonable. > > It does sound like we agree that the existing behavior of waking up > every 5s or 2.5s is not good. I hope you will act to improve that. > > The approach taken in this patch, and others of mine, has been to > offer a minimal change that achieves the objective of lengthy > hibernation to save power. > > Removing the timeout entirely may not work in other circumstances I > have not explored. Doing that requires someone to check it actually > works, and for others to believe that check has occurred. For me, that > is too time consuming to actually happen in this dev cycle, and time > is part of the objective since perfect designs yet with unreleased > code have no utility. > > <Simon enters lengthy hibernation>
<Thomas returns from aestivation> Yeah, I definitely want to fix it. I just worry that 60s is so long that it also needs that analysis work to be done to explain that it's OK that we're a bit sloppy on noticing when to wake up, at which point you might as well go to infinity.
