+ stable + regressions New subject

Great news.

Greg, Sasha,

Can you please pull in these 3 commits specifically to 6.6.y to fix a regression that was reported by Morgan in 6.6.y:

commit 12753d71e8c5 ("ACPI: CPPC: Add helper to get the highest performance value") commit ed429c686b79 ("cpufreq: amd-pstate: Enable amd-pstate preferred core support") commit 3d291fe47fe1 ("cpufreq: amd-pstate: fix the highest frequency issue which limits performance")

Further details are below.

Thanks!

On 9/5/2024 16:09, Jones, Morgan wrote:

Mario,

Confirmed. Thank you for the help! Slightly different refs on my end:

Remotes:

next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git (fetch) next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git (push) origin git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git (fetch) origin git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git (push) superm1 https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git/ (fetch) superm1 https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git/ (push) torvalds git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git (fetch) torvalds git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git (push)

Patches:

git format-patch 12753d71e8c5^..12753d71e8c5 git format-patch f3a052391822b772b4e27f2594526cf1eb103cab^..f3a052391822b772b4e27f2594526cf1eb103cab git format-patch bf202e654bfa57fb8cf9d93d4c6855890b70b9c4^..bf202e654bfa57fb8cf9d93d4c6855890b70b9c4

Results:

Linux redact 6.6.48 #1-NixOS SMP PREEMPT_DYNAMIC Tue Jan 1 00:00:00 UTC 1980 x86_64 GNU/Linux

analyzing CPU 56: driver: amd-pstate-epp CPUs which run at the same hardware frequency: 56 CPUs which need to have their frequency coordinated by software: 56 maximum transition latency: Cannot determine or is not supported. hardware limits: 400 MHz - 3.35 GHz available cpufreq governors: performance powersave current policy: frequency should be within 400 MHz and 3.35 GHz. The governor "performance" may decide which speed to use within this range. current CPU frequency: Unable to call hardware current CPU frequency: 2.09 GHz (asserted by call to kernel) boost state support: Supported: yes Active: yes AMD PSTATE Highest Performance: 255. Maximum Frequency: 3.35 GHz. AMD PSTATE Nominal Performance: 152. Nominal Frequency: 2.00 GHz. AMD PSTATE Lowest Non-linear Performance: 115. Lowest Non-linear Frequency: 1.51 GHz. AMD PSTATE Lowest Performance: 31. Lowest Frequency: 400 MHz.

And our builds are back to being fast with `amd_pstate=active amd_prefcore=enable amd_pstate.shared_mem=1`.

Morgan

-----Original Message----- From: Mario Limonciello mario.limonciello@amd.com Sent: Thursday, September 5, 2024 8:12 AM To: Jones, Morgan Morgan.Jones@viasat.com Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; David Arcari darcari@redhat.com; Dhananjay Ugwekar Dhananjay.Ugwekar@amd.com; rafael@kernel.org; viresh.kumar@linaro.org; gautham.shenoy@amd.com; perry.yuan@amd.com; skhan@linuxfoundation.org; li.meng@amd.com; ray.huang@amd.com Subject: Re: [EXTERNAL] Re: [PATCH v2 2/2] cpufreq/amd-pstate: Fix the scaling_max_freq setting on shared memory CPPC systems

Hi Morgan,

Please apply these 3 commits:

commit 12753d71e8c5 ("ACPI: CPPC: Add helper to get the highest performance value") commit ed429c686b79 ("cpufreq: amd-pstate: Enable amd-pstate preferred core support") commit 3d291fe47fe1 ("cpufreq: amd-pstate: fix the highest frequency issue which limits performance")

The first two should help your system, the third will prevent introducing a regression on a different one.

Assuming that works we should ask @stable to pull all 3 in to fix this regression.

Thanks,

On 9/4/2024 08:57, Mario Limonciello wrote:

...

Morgan,

I was referring specfiically to the version that landed in Linus' tree: https://urldefense.us/v3/__https://git.kernel.org/torvalds/c/8164f7433 264__;!!C5Asm8uRnZQmlRln!aIZEDEbIUKD7OrxN0b0KjoqKYDL2yMkwk4EK7x_oSnyHQ 6MEq7yt6JHjd0TD9DgEYEWDcF58OKL8c7G11bT3dSqL8eM$

But yeah it's effectively the same thing.  In any case, it's not the solution.

We had some internal discussion and suspect this is due to missing prefcore patches in 6.6 as that feature landed in 6.9.  We'll try to reproduce this on a Rome system and come back with our findings and suggestions what to do.

Thanks,