From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Linux PM <linux-pm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Lukasz Luba <lukasz.luba@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Pierre Gondois <pierre.gondois@arm.com>,
Christian Loehle <christian.loehle@arm.com>
Subject: Re: [PATCH v2 2/7] cpufreq/sched: Move cpufreq-specific EAS checks to cpufreq
Date: Mon, 12 May 2025 19:24:35 +0200 [thread overview]
Message-ID: <70cadfd8-8d5c-4685-b3d0-23cde6edc522@arm.com> (raw)
In-Reply-To: <CAJZ5v0iLr3JZ49gX9XbkjPNr_wRDMyAtMZDZ6Aoxz1KgQZ_moA@mail.gmail.com>
On 12/05/2025 14:53, Rafael J. Wysocki wrote:
> On Mon, May 12, 2025 at 8:48 AM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>>
>> On 10.05.2025 13:31, Rafael J. Wysocki wrote:
>>> On Sat, May 10, 2025 at 1:49 AM Marek Szyprowski
>>> <m.szyprowski@samsung.com> wrote:
>>>> On 06.05.2025 22:37, Rafael J. Wysocki wrote:
>>>>> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[...]
>>>> *** DEADLOCK ***
>>> Well, it turns out that trying to acquire policy->rwsem under
>>> sched_domains_mutex is a bad idea. It was added to
>>> cpufreq_policy_is_good_for_eas() to address a theoretical race, so it
>>> can be dropped safely. A theoretical race is better than a real
>>> deadlock.
>>>
>>> Please test the attached patch.
>>
>> This fixed the observed issue. Thanks!
>>
>> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
>
> Thanks for the confirmation!
See this on my Hikey 960 as well. I was wondering why Christian L. and I
didn't catch this with RFT v1.0 (*) on i7-13700K.
But it looks like that
https://web.git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=experimental/intel_pstate/eas-take2-extended
mentioned in the patch-header of (*) didn't have this line in its
commit 9ad047cade6b ("cpufreq/sched: Move cpufreq-specific EAS checks to
cpufreq")
next prev parent reply other threads:[~2025-05-12 17:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-06 20:32 [PATCH v2 0/7] cpufreq: intel_pstate: Enable EAS on hybrid platforms without SMT Rafael J. Wysocki
2025-05-06 20:34 ` [PATCH v2 1/7] cpufreq/sched: schedutil: Add helper for governor checks Rafael J. Wysocki
2025-05-06 20:37 ` [PATCH v2 2/7] cpufreq/sched: Move cpufreq-specific EAS checks to cpufreq Rafael J. Wysocki
2025-05-09 23:49 ` Marek Szyprowski
2025-05-10 11:31 ` Rafael J. Wysocki
2025-05-12 6:48 ` Marek Szyprowski
2025-05-12 12:53 ` Rafael J. Wysocki
2025-05-12 17:24 ` Dietmar Eggemann [this message]
2025-05-12 17:47 ` Rafael J. Wysocki
2025-05-06 20:39 ` [PATCH v2 3/7] PM: EM: Move CPU capacity check to em_adjust_new_capacity() Rafael J. Wysocki
2025-05-06 20:41 ` [PATCH v2 4/7] PM: EM: Introduce em_adjust_cpu_capacity() Rafael J. Wysocki
2025-05-06 20:44 ` [PATCH v2 5/7] cpufreq: intel_pstate: EAS support for hybrid platforms Rafael J. Wysocki
2025-05-06 20:47 ` [PATCH v2 6/7] cpufreq: intel_pstate: EAS: Increase cost for CPUs using L3 cache Rafael J. Wysocki
2025-05-06 20:48 ` [PATCH v2 7/7] cpufreq: intel_pstate: Document hybrid processor support Rafael J. Wysocki
2025-05-13 12:51 ` [PATCH v2 0/7] cpufreq: intel_pstate: Enable EAS on hybrid platforms without SMT Rafael J. Wysocki
2025-05-13 14:01 ` Rafael J. Wysocki
2025-06-29 12:28 ` Ibrahim Ansari
2025-06-30 18:51 ` Rafael J. Wysocki
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