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From: Jianyong Wu <wujianyong@hygon.cn>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>,
	"viresh.kumar@linaro.org" <viresh.kumar@linaro.org>,
	"kprateek.nayak@amd.com" <kprateek.nayak@amd.com>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"ray.huang@amd.com" <ray.huang@amd.com>,
	"mario.limonciello@amd.com" <mario.limonciello@amd.com>,
	"perry.yuan@amd.com" <perry.yuan@amd.com>,
	"zhanjie9@hisilicon.com" <zhanjie9@hisilicon.com>,
	"zhenglifeng1@huawei.com" <zhenglifeng1@huawei.com>,
	"pierre.gondois@arm.com" <pierre.gondois@arm.com>,
	"sumitg@nvidia.com" <sumitg@nvidia.com>,
	"srinivas.pandruvada@linux.intel.com"
	<srinivas.pandruvada@linux.intel.com>,
	"hongyan.xia@transsion.com" <hongyan.xia@transsion.com>,
	"zhongqiu.han@oss.qualcomm.com" <zhongqiu.han@oss.qualcomm.com>,
	Fengyu Wang <wangfengyu@hygon.cn>,
	Yuan Zhong <zhongyuan@hygon.cn>, Huangsj <huangsj@hygon.cn>
Subject: RE: [PATCH] cpufreq: Use a non-boost reference frequency for pressure calculation
Date: Mon, 21 Sep 2026 08:55:00 +0000	[thread overview]
Message-ID: <ddf15b0e0f4b4c7290e6324b963a234f@hygon.cn> (raw)
In-Reply-To: <5135696.31r3eYUQgx@rafael.j.wysocki>



On Fri, Sep 18, 2026, Rafael J. Wysocki wrote:
> So actually the problem is that now the pressure is applied when it is not
> expected to be applied in general.
> 
Yes.

> Clearly, the scheduler assumes that the pressure will be zero when
> arch_scale_freq_ref() is zero and the commit in question violates that
> assumption.
> 
> This actually has a little to do with boost and making it depend on boost
> doesn't really help.  In fact, the reason for making the change was some
> inadequate behavior when intel_pstate ran with asym capacity, so
> something
> like the patch below (completely untested) can be used to limit the scope
> of it to the case in question.
> 
> Can you please check if it helps?

Yes it helps.

I tested it on Hygon and an AMD system using acpi-cpufreq. The cpu
pressure is zero again, and cache aware scheduling can once more
aggregate tasks up to 50% of the LLC capacity, as it did before
d2d5c129d07e.

Tested-by: Jianyong Wu <wujianyong@hygon.cn>

Thanks
Jianyong

      reply	other threads:[~2026-09-21  8:55 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-15  6:57 [PATCH] cpufreq: Use a non-boost reference frequency for pressure calculation Jianyong Wu
2026-09-15  9:32 ` Hongyan Xia
2026-09-15 12:46   ` Jianyong Wu
2026-09-17 17:38 ` Rafael J. Wysocki (Intel)
2026-09-17 18:34   ` Mario Limonciello
2026-09-18  5:59     ` Jianyong Wu
2026-09-18  4:08   ` Jianyong Wu
2026-09-18 18:19     ` Rafael J. Wysocki
2026-09-21  8:55       ` Jianyong Wu [this message]

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