linux-kernel - Re: [PATCH 7/8] cpufreq: amd-pstate: Optimize amd_pstate_update

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: <Zs4FaUoKzlKpoCDV@BLRRASHENOY1.amd.com>
Date: Tue, 27 Aug 2024 22:27:13 +0530
From: "Gautham R. Shenoy" <gautham.shenoy@....com>
To: Mario Limonciello <superm1@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>, Perry Yuan <perry.yuan@....com>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <linux-kernel@...r.kernel.org>,
	"open list:ACPI" <linux-acpi@...r.kernel.org>,
	"open list:CPU FREQUENCY SCALING FRAMEWORK" <linux-pm@...r.kernel.org>,
	Mario Limonciello <mario.limonciello@....com>
Subject: Re: [PATCH 7/8] cpufreq: amd-pstate: Optimize
 amd_pstate_update_limits()

On Mon, Aug 26, 2024 at 04:13:57PM -0500, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@....com>
> 
> Don't take and release the mutex when prefcore isn't present and
> avoid initialization of variables that will be initially set
> in the function.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>

> ---
>  drivers/cpufreq/amd-pstate.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 75568d0f84623..ed05d7a0add10 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -798,17 +798,17 @@ static void amd_pstate_update_limits(unsigned int cpu)
>  	int ret;
>  	bool highest_perf_changed = false;
>  
> -	mutex_lock(&amd_pstate_driver_lock);
> -	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
> -		goto free_cpufreq_put;
> +	if (!amd_pstate_prefcore)
> +		return;

Looks good to me.

Wondering if it is worth maintaining a static key for
amd_pstate_prefcore. Anyway it doesn't change after boot.

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


--
Thanks and Regards
gautham.