Dear Borislav,
Am 02.04.21 um 16:05 schrieb Borislav Petkov:
On Fri, Apr 02, 2021 at 10:33:51AM +0200, Paul Menzel wrote:
On an two socket AMD EPYC 7601, we noticed a decrease in raid6 avx2x4 speed
shown at the beginning of the boot.
5.4.95 5.10.24
----------------------------------------------
raid6: avx2x4 gen() 18429 MB/s 6155 MB/s
raid6: avx2x4 xor() 6644 MB/s 4274 MB/s
raid6: avx2x2 gen() 17894 MB/s 18744 MB/s
raid6: avx2x2 xor() 11642 MB/s 11950 MB/s
raid6: avx2x1 gen() 13992 MB/s 17112 MB/s
raid6: avx2x1 xor() 10855 MB/s 11143 MB/s
Looks like those two might help:
49200d17d27d x86/fpu/64: Don't FNINIT in kernel_fpu_begin()
e45122893a98 x86/fpu: Add kernel_fpu_begin_mask() to selectively initialize
state
I booted Linux 5.12-rc6, containing these commits, on a Dell OptiPlex
5055 with AMD Ryzen 5 PRO 1500 Quad-Core Processor, and the regression
is still present for `avx2x4 xor()`:
5.4.95 5.10.24
----------------------------------------------
raid6: avx2x4 gen() 23964 MB/s 24540 MB/s
raid6: avx2x4 xor() 13101 MB/s 8354 MB/s
raid6: avx2x2 gen() 22746 MB/s 26972 MB/s
raid6: avx2x2 xor() 14917 MB/s 16463 MB/s
raid6: avx2x1 gen() 17519 MB/s 24394 MB/s
raid6: avx2x1 xor() 14091 MB/s 15330 MB/s
raid6: sse2x4 gen() 16867 MB/s 16136 MB/s
raid6: sse2x4 xor() 9667 MB/s 8176 MB/s
raid6: sse2x2 gen() 14996 MB/s 18234 MB/s
raid6: sse2x2 xor() 10765 MB/s 10455 MB/s
raid6: sse2x1 gen() 7667 MB/s 13769 MB/s
raid6: sse2x1 xor() 7818 MB/s 7741 MB/s
What system are you using, and what results do you get with 5.4 and
5.12-rc6?
Kind regards,
Paul
