linux-kernel - Re: [PATCH 11/15] cpufreq/amd-pstate: Cache EPP value and use that everywhere

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Z1Mi7hclcaSaRRjO@BLRRASHENOY1.amd.com>
Date: Fri, 6 Dec 2024 21:44:38 +0530
From: "Gautham R. Shenoy" <gautham.shenoy@....com>
To: Mario Limonciello <mario.limonciello@....com>
Cc: Perry Yuan <perry.yuan@....com>, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>
Subject: Re: [PATCH 11/15] cpufreq/amd-pstate: Cache EPP value and use that
 everywhere

Hello Mario,

On Thu, Dec 05, 2024 at 04:28:43PM -0600, Mario Limonciello wrote:
> Cache the value in cpudata->epp_cached, and use that for all callers.
> As all callers use cached value merge amd_pstate_get_energy_pref_index()
> into show_energy_performance_preference().
> 
> Check if the EPP value is changed before writing it to MSR or
> shared memory region.

The patch looks ok to me. Just one comment below:

[..snip..]

> @@ -1610,6 +1591,8 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>  
>  	cpudata->policy = policy->policy;
>  
> +	guard(mutex)(&amd_pstate_limits_lock);
> +

Shouldn't this hunk be a different patch. The changelog doesn't say
anything about making amd_pstate_epp_update_limit() call while holding
the amd_pstate_limits_lock.


>  	ret = amd_pstate_epp_update_limit(policy);
>  	if (ret)
>  		return ret;
> -- 
> 2.43.0
>

For the rest of the patch

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@....com>

--
Thanks and Regards
gautham.