On Mon, Mar 02, 2015 at 10:56:14PM -0800, Linus Torvalds wrote:
> On Mon, Mar 2, 2015 at 9:20 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> >> But are those migrate-page calls really common enough to make these
> >> things happen often enough on the same pages for this all to matter?
> > It's looking like that's a possibility.
> Hmm. Looking closer, commit 10c1045f28e8 already should have
> re-introduced the "pte was already NUMA" case.
> So that's not it either, afaik. Plus your numbers seem to say that
> it's really "migrate_pages()" that is done more. So it feels like the
> numa balancing isn't working right.
So that should show up in the vmstats, right? Oh, and there's a
tracepoint in migrate_pages, too. Same 6x10s samples in phase 3:
And a sample of the events shows 99.99% of these are:
mm_migrate_pages: nr_succeeded=1 nr_failed=0 mode=MIGRATE_ASYNC reason=
They are also single page MIGRATE_ASYNC events like for 3.19.
And 'grep "numa\|migrate" /proc/vmstat' output for the entire