On Fri, Oct 18, 2019 at 06:40:24PM -0700, Andrew Morton wrote: > On Fri, 18 Oct 2019 15:09:59 +0100 Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > Cc: stable@xxxxxxxxxxxxxxx # v4.15+ > > > > > > Hmm, are you sure about 4.15? Doesn't this go all the way down to > > > deferred initialization? I do not see any recent changes on when > > > setup_per_cpu_pageset is called. > > > > > > > No, I'm not 100% sure. It looks like this was always an issue from the > > code but did not happen on at least one 4.12-based distribution kernel for > > reasons that are non-obvious. Either way, the tag should have been "v4.1+" > > I could mark > > mm-pcp-share-common-code-between-memory-hotplug-and-percpu-sysctl-handler.patch > mm-meminit-recalculate-pcpu-batch-and-high-limits-after-init-completes.patch > > as Cc: <stable@xxxxxxxxxxxxxxx> [4.1+] > That would be fine. > But for backporting purposes it's a bit cumbersome that [2/3] is the > important patch. I think I'll switch the ordering so that > mm-meminit-recalculate-pcpu-batch-and-high-limits-after-init-completes.patch > is the first patch and the other two can be queued for 5.5-rc1, OK? > It might be easier to simply collapse patch 1 and 2 together. They were only split to make the review easier and to avoid two relatively big changes in one patch. > Also, is a Reported-by:Matt appropriate here? > I don't object but I'm not actually sure who reported this first. I think it was Thomas who talked to Boris about an EPYC performance issue, who talked to Matt thinking it might be a scheduler issue who identified it was my problem :P -- Mel Gorman SUSE Labs
