Re: regression/bisected commit 773688a6cb24b0b3c2ba40354d883348a2befa38 make my system completely unusable under high load

From: Mikhail Gavrilov
Date: Fri Jan 19 2024 - 12:55:20 EST


On Fri, Jan 19, 2024 at 4:00 PM Marco Elver <elver@xxxxxxxxxx> wrote:
> I was afraid this would happen - could you try this patch series:
> https://lore.kernel.org/all/20240118110216.2539519-2-elver@xxxxxxxxxx/ [1]

Thanks, this patch series definitely helped.
I can again work at the computer when something is compiling in the background.
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@xxxxxxxxx>

> In addition, could you give some additional details about the number
> of CPUs in your system?

Hardware probe: https://linux-hardware.org/?probe=ba941d7a4e
CPU: AMD Ryzen 7950x

> And if possible, do you have a way to measure performance besides the
> obvious lagging of the system? It would be interesting to know if the
> fix in [1] regains performance fully.

perf-2d5524635b00.data -
https://mega.nz/file/Q0ACSI4a#QQ8Ntbw5zvP_YZMsXPzSr-PxLVCw8fwg2RJaVOghoOQ
perf-773688a6cb24.data -
https://mega.nz/file/F8wAgBZI#OQ75qLFyf2diFXrDs9bP6_5xDevVrs1KlNdeupWSJSQ
perf-with-patchset.data -
https://mega.nz/file/l8ZXnI6Y#SmrZpH2Em6xzlIZgJe50PwSw-zLK_4whRjx3t_058kE

> perf diff perf-2d5524635b00.data perf-773688a6cb24.data
No kallsyms or vmlinux with build-id
c64a03a51e9503a251dbec8e5267fb3ae51914f2 was found
# Event 'cycles:P'
#
# Baseline Delta Abs Shared Object
Symbol

>
# ........ ......... ..............................................
...................................................................................................................................................................>
#
59.91% +23.05% [kernel.vmlinux]
[k] 0xffffffff940065c0
17.88% -7.89% cc1
[.] 0x0000000000207020
9.39% -6.30% cc1plus
[.] 0x0000000000225110
1.37% -1.29% libpython3.12.so.1.0
[.] 0x00000000000647e0
1.16% -0.84% libcef.so
[.] 0x00000000021720e0
1.27% -0.67% as
[.] 0x0000000000002090
0.78% -0.54% steamclient.so
[.] 0x00000000001ed915
0.77% -0.33% chrome
[.] 0x0000000002892080
0.54% -0.32% libc.so.6
[.] _int_malloc
0.30% -0.23% libpixman-1.so.0.43.0
[.] 0x00000000000078a7
0.31% -0.19% libc.so.6
[.] _int_free


> perf diff perf-2d5524635b00.data perf-with-patchset.data
# Event 'cycles:P'
#
# Baseline Delta Abs Shared Object
Symbol

>
# ........ ......... ..............................................
...................................................................................................................................................................>
#
17.88% +12.61% cc1
[.] 0x0000000000207020
+3.89% [kernel.vmlinux]
[k] unwind_next_frame
+3.53% [kernel.vmlinux]
[k] kasan_check_range
+2.54% [kernel.vmlinux]
[k] debug_check_no_obj_freed
9.39% +2.10% cc1plus
[.] 0x0000000000225110
+1.87% [kernel.vmlinux]
[k] rcu_is_watching
+1.41% [kernel.vmlinux]
[k] lock_release
+1.24% [kernel.vmlinux]
[k] __orc_find
+1.21% [kernel.vmlinux]
[k] lock_acquire
+1.08% [kernel.vmlinux]
[k] stack_trace_consume_entry
+1.08% [kernel.vmlinux]
[k] check_preemption_disabled
1.37% +1.01% libpython3.12.so.1.0
[.] 0x00000000000647e0
+0.96% [kernel.vmlinux]
[k] stack_access_ok
1.27% +0.79% as
[.] 0x0000000000002090


Thanks!

--
Best Regards,
Mike Gavrilov.