Re: [x86/mm/pat] 8d04a5f97a: phoronix-test-suite.glmark2.0.score -23.7% regression

[Mariusz Ceier]

Contents of /sys/kernel/debug/x86/pat_memtype_list on master
(32ef9553635ab1236c33951a8bd9b5af1c3b1646) where performance is
degraded:

PAT memtype list:
write-back @ 0x55ba4000-0x55ba5000
write-back @ 0x5e88c000-0x5e8b5000
write-back @ 0x5e8b4000-0x5e8b5000
write-back @ 0x5e8b4000-0x5e8b8000
write-back @ 0x5e8b7000-0x5e8bb000
write-back @ 0x5e8ba000-0x5e8bc000
write-back @ 0x5e8bb000-0x5e8be000
write-back @ 0x5e8bd000-0x5e8bf000
write-back @ 0x5e8be000-0x5e8c2000
write-back @ 0x5ef3c000-0x5ef3d000
write-back @ 0x5ef6c000-0x5ef6d000
write-back @ 0x5ef6f000-0x5ef70000
write-back @ 0x5ef72000-0x5ef73000
write-back @ 0x5f5b3000-0x5f5b5000
uncached-minus @ 0xe3f00000-0xe3f10000
uncached-minus @ 0xec000000-0xec040000
uncached-minus @ 0xec002000-0xec003000
uncached-minus @ 0xec110000-0xec111000
uncached-minus @ 0xec200000-0xec240000
uncached-minus @ 0xec260000-0xec264000
uncached-minus @ 0xec300000-0xec320000
uncached-minus @ 0xec326000-0xec327000
uncached-minus @ 0xf0000000-0xf8000000
uncached-minus @ 0xf0000000-0xf0001000
uncached-minus @ 0xfdc43000-0xfdc44000
uncached-minus @ 0xfe000000-0xfe001000
uncached-minus @ 0xfed00000-0xfed01000
uncached-minus @ 0xfed10000-0xfed16000
uncached-minus @ 0xfed90000-0xfed91000
uncached-minus @ 0x2000000000-0x2100000000
uncached-minus @ 0x2000000000-0x2100000000
uncached-minus @ 0x2100000000-0x2100001000
uncached-minus @ 0x2100001000-0x2100002000
uncached-minus @ 0x2ffff10000-0x2ffff20000
uncached-minus @ 0x2ffff20000-0x2ffff24000

Contents of /sys/kernel/debug/x86/pat_memtype_list after reverting
7f264dab5b60, 511aaca834fe, 6a9930b1c50d, 8d04a5f97a5f (in that order)
which restores the performance:

PAT memtype list:
write-back @ 0x55ba4000-0x55ba5000
write-back @ 0x5e88c000-0x5e8b5000
write-back @ 0x5e8b4000-0x5e8b8000
write-back @ 0x5e8b4000-0x5e8b5000
write-back @ 0x5e8b7000-0x5e8bb000
write-back @ 0x5e8ba000-0x5e8bc000
write-back @ 0x5e8bb000-0x5e8be000
write-back @ 0x5e8bd000-0x5e8bf000
write-back @ 0x5e8be000-0x5e8c2000
write-back @ 0x5ef3c000-0x5ef3d000
write-back @ 0x5ef6c000-0x5ef6d000
write-back @ 0x5ef6f000-0x5ef70000
write-back @ 0x5ef72000-0x5ef73000
write-back @ 0x5f5b3000-0x5f5b5000
uncached-minus @ 0xe3f00000-0xe3f10000
uncached-minus @ 0xec000000-0xec040000
uncached-minus @ 0xec002000-0xec003000
uncached-minus @ 0xec110000-0xec111000
uncached-minus @ 0xec200000-0xec240000
uncached-minus @ 0xec260000-0xec264000
uncached-minus @ 0xec300000-0xec320000
uncached-minus @ 0xec326000-0xec327000
uncached-minus @ 0xf0000000-0xf0001000
uncached-minus @ 0xf0000000-0xf8000000
uncached-minus @ 0xfdc43000-0xfdc44000
uncached-minus @ 0xfe000000-0xfe001000
uncached-minus @ 0xfed00000-0xfed01000
uncached-minus @ 0xfed10000-0xfed16000
uncached-minus @ 0xfed90000-0xfed91000
write-combining @ 0x2000000000-0x2100000000
write-combining @ 0x2000000000-0x2100000000
uncached-minus @ 0x2100000000-0x2100001000
uncached-minus @ 0x2100001000-0x2100002000
uncached-minus @ 0x2ffff10000-0x2ffff20000
uncached-minus @ 0x2ffff20000-0x2ffff24000

Hope this helps (if you need the contents from commits exactly
8d04a5f97a5f and 8d04a5f97a5f~1, I can provide it, but it will take
more time).

Best regards,
Mariusz Ceier

On Sat, 30 Nov 2019 at 21:31, Davidlohr Bueso <dave@xxxxxxxxxxxx> wrote:
>
> On Sat, 30 Nov 2019, Mariusz Ceier wrote:
>
> >I can also confirm this - just bisected framebuffer rendering
> >performance regression on amdgpu and
> >8d04a5f97a5fa9d7afdf46eda3a5ceaa973a1bcc is the first bad commit
> >(leading to drop from around 260-300fps to about 60fps in CS:GO on
> >Fury X).
>
> This is a third report now. Could you please provide the contents
> of the following file, before and after the offending commit.
>
>         /sys/kernel/debug/x86/pat_memtype_list
>
> This will show any attribute differences in the tree, which is likely
> the culprit.
>
> Thanks,
> Davidlohr