From nobody Fri Oct 3 23:11:41 2025 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3009E17BA9 for ; Sat, 23 Aug 2025 00:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755908431; cv=none; b=adVb7wzqCM8bm11Z0z1mmhaJQYyLhjSivCmisdcged/Bk7izbK9T/p7LGsdOrjhDLUMkgXcYYmId6dkYR/gfLK1j8skN7FG4asHzLMAs8Lml9XcH05d0rHNV0J0Cgad1rxGi+iAx0BCfU/p+ElQ9KZjLpQaOTt6hpEy45CXhj30= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755908431; c=relaxed/simple; bh=IzXBy0JDm5P7DeRxtoCFvOVrJJzRcpwGhg/ODLS/f4o=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fhw4tIfRrOEETIts9euQEsL1migCvmG5zYEPaG+3UlhwJSsVlK8EBaUafaLLl3052X46e4prGxVzQ/IDYd47qTyz6zHexBZ2Lh0gb/8xD6TzPcc2y6rPbe9BHFRb/3bf6a1CXt8AYYLGsdTWzDyyYEgTPkN23HyAITkyAsFMKEM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--pmalani.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=C/LoIvV3; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--pmalani.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="C/LoIvV3" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-76e2eb787f2so2898175b3a.3 for ; Fri, 22 Aug 2025 17:20:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1755908429; x=1756513229; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=IkunMuqOTjzTmYvfp0kTEUrdTSxEiMipgCHfYoiQGpg=; b=C/LoIvV3G5gGWak0Zg6/TA3X1Ee+kQiFe8bRwpI7RqJtMtZ/7rkbRdN2fstSA5S5V5 E1iOEXKfiTMUrWtTe5EdZPI0wL0IQlNIvxvH0mL7DDUsV6zWHxbg8c9TebQ2t/rNlUWN 8YS+qyzEZNETXoW8jhGOsBSfprRw84MCZBoTkzo0dnG33URLhIWlvzw+KwaHIek5gdig utGKizGKOYcdJcfqf2Nf6aPQSPVlHPlklF456hMkVTZkZJFAagapprQBxmiGly1Sfz2T VLSqicJxy/9pvuW0oIyZVDjGI3tssbPA7IfOy5iOwWDRyjDPiYvQVcGN3poeYfuTAlso b0uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755908429; x=1756513229; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=IkunMuqOTjzTmYvfp0kTEUrdTSxEiMipgCHfYoiQGpg=; b=dnO/yebp2nUHQs6ojgvCweaa/G8g751tepAG1CwBGvRxi0Wb9dR847RExrtgi1kKcm zy1kzKt4PHYnmokkl49n8tCMyFTzfo6wCTwE9hel2LSL6TtPXDgRh0L51FNNR6YECTfK YkT3hJPlKfuwd7pXhaifu7yMBBDUK8Wz5u3u3exR+Cii6DwO7/Lhd1BYIivJBWai4eLz ttYwcroPbqzSK/IE9sEhh0vVfXk5G4VsRMNG5UjctFEshunOUMwAUJ2SJT3EeKs93Yfr uansj7z+0HTObXfuyAzjn7VzgZx8o6c8Ic2ZMlHSJmlDmwaKWqQbywMX3VJfCKFlzqMj u/6A== X-Gm-Message-State: AOJu0YyH+MkAfovUCfUbHGwCCn58gUs8Y5PeIrDQtNxWqMc39mJzLIkt Y6jmxzLenfPScW6pYqj6rQjjqQmGSdnopE556iLyt9QcFTuSCIDjo1+BAfbzPKPX/Tv0f5w4c22 MH/PMdc9qlBGjcrpglPTRqVcGjRCM2Bi3OxRB/SUY/NZYrsHnM1vmBG3QGFR6/Dh5TO4EX774Gi 9t4jnKnn/cB9/g3AUT6lDmmlDBQslmcVo/BpXOyAQHJMKi5ioWRQ== X-Google-Smtp-Source: AGHT+IH2meIMrbfg6cA0DiATMI+gqKbNcFZVYHUt9TbVkruM9LnU8cXpri5WfeUocsKnglMv3dRahkUsS8Mf X-Received: from pfbfa6.prod.google.com ([2002:a05:6a00:2d06:b0:76c:555a:bfaa]) (user=pmalani job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:430a:b0:233:927b:3ffa with SMTP id adf61e73a8af0-24340b7ca46mr6933649637.12.1755908429227; Fri, 22 Aug 2025 17:20:29 -0700 (PDT) Date: Sat, 23 Aug 2025 00:17:50 +0000 In-Reply-To: <20250823001937.2765316-1-pmalani@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250823001937.2765316-1-pmalani@google.com> X-Mailer: git-send-email 2.51.0.rc2.233.g662b1ed5c5-goog Message-ID: <20250823001937.2765316-5-pmalani@google.com> Subject: [PATCH 2/2] cpufreq: CPPC: Don't verify cur frequency on governor start From: Prashant Malani To: open list , "open list:CPU FREQUENCY SCALING FRAMEWORK" , "Rafael J. Wysocki" , Viresh Kumar Cc: Beata Michalska , Prashant Malani Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Opt in to not verifying the policy's current frequency when the governor starts. CPPC's get() function is known to return unreliable values, so checking against that can mean the frequency gets set to the unreliable value even though the governor (and user) didn't intend to do so. That in turn causes unexpected performance drops. Cc: Beata Michalska Signed-off-by: Prashant Malani --- drivers/cpufreq/cppc_cpufreq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 4a17162a392d..7fd6c03bb726 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -910,7 +910,8 @@ static struct freq_attr *cppc_cpufreq_attr[] =3D { }; =20 static struct cpufreq_driver cppc_cpufreq_driver =3D { - .flags =3D CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, + .flags =3D CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS | + CPUFREQ_DONT_VERIFY_FREQ_ON_GOVERNOR_START, .verify =3D cppc_verify_policy, .target =3D cppc_cpufreq_set_target, .get =3D cppc_cpufreq_get_rate, --=20 2.51.0.rc2.233.g662b1ed5c5-goog