> On 22 Nov 2021, at 14:05, Michail Nikolaev <michail.nikol...@gmail.com> wrote: > >> Write barrier must be issued after write, not before. >> Don't we need to issue read barrier too? > > The write barrier is issued after the changes to KnownAssignedXidsNext > and KnownAssignedXidsValid arrays and before the update of > headKnownAssignedXids. > So, it seems to be correct. We make sure once the CPU sees changes of > headKnownAssignedXids - underlying arrays contain all the required > data.
Patch on barrier seems too complicated to me right now. I’d propose to focus on KnowAssignedXidsNext patch: it’s clean, simple and effective. I’ve rebased the patch so that it does not depend on previous step. Please check out it’s current state, if you are OK with it - let’s mark the patch Ready for Committer. Just maybe slightly better commit message would make the patch easier to understand. Thanks! Best regards, Andrey Borodin.
v4-0001-Use-linked-list-to-improve-KnownAssignedXids-perf.patch
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