Re: [PATCH v4 0/7] mm: Remember a/d bits for migration entries

Peter Xu
2022-11-21T15:08:54Z

Hi, Raghavendra,

On Mon, Nov 21, 2022 at 10:45:45AM +0530, Raghavendra K T wrote:
> I was able to test on AMD EPYC 64 core 2 numa node (Milan) 3.72 GHz clocked
> system
>
> am seeing the similar improvement for the test mentioned above (swap-young)
>
> base: (6.0)
> --------------
> Write (node 0) took 562202 (us)
> Read (node 0) took 7790 (us)
> Move to node 1 took 474876(us)
> Move to node 0 took 642805(us)
> Read (node 0) took 81364 (us)
> Write (node 0) took 12887 (us)
> Read (node 0) took 5202 (us)
> Write (node 0) took 4533 (us)
> Read (node 0) took 5229 (us)
> Write (node 0) took 4558 (us)
> Read (node 0) took 5198 (us)
> Write (node 0) took 4551 (us)
> Read (node 0) took 5218 (us)
> Write (node 0) took 4534 (us)
>
> patched
> -------------
> Write (node 0) took 250232 (us)
> Read (node 0) took 3262 (us)
> Move to node 1 took 640636(us)
> Move to node 0 took 449051(us)
> Read (node 0) took 2966 (us)
> Write (node 0) took 2720 (us)
> Read (node 0) took 2891 (us)
> Write (node 0) took 2560 (us)
> Read (node 0) took 2899 (us)
> Write (node 0) took 2568 (us)
> Read (node 0) took 2890 (us)
> Write (node 0) took 2568 (us)
> Read (node 0) took 2897 (us)
> Write (node 0) took 2563 (us)
>
> Please feel free to add FWIW
> Tested-by: Raghavendra K T <raghavendra.kt@amd.com>

The series has already landed v6.1-rc1 so it should be a bit late to apply
the tested-by tag, but still thanks a lot for your tests and upate!

It seems the mem size is different for the two rounds of test as even the
initial write differs in time, but I think that still explains the
difference because what matters is the first read/write after migration,
and that can be compared with the 2nd/3rd/... reads/writes afterwards.

Side note: there's actually one tiny thing got removed from the series on
handling dirty bit of thp split (434e3d15d92b), but it seems there's hope
we cound have found the root issue of the issues on sparc64 and loongarch
so we may have chance to re-apply them.

--
Peter Xu