From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (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 18AE83D68 for ; Tue, 30 Jan 2024 00:05:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706573130; cv=none; b=heaWIwa0yBCN0nLWgVGEzzuJOThqoaAuOAok3+Dw+3a9sL6JnaUuQFQgxcwtFO2wvJBal9lrDc3v2A8o+pWiN4MMOkv9QrBV4j2ghyFnmgS0fbKqGGUWU7s7UC/i7TiEskxuM7nvzaSFTB0d2NRx1WYAdgwtA60Co1/tDzUMV4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706573130; c=relaxed/simple; bh=m+0FwiboCnTUjVYArGv7RhH9oT8oe6HzEysbTX1aTGc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hAPbrl24M9hofqAip3obaeTUQWH6r7+5CpyWlu+u/PqBwfZwrvA+RWiGKEJwPH97uf0zcF1FLQ592Y/dMfqmbOqtRZ4CaHGe5nGKfDEM1bd8Ebz8poeMEx9Oy2axhg5KeTEK9vi9tBWy6DRll5HPcfCkgDE42I0qzyIFo7c5i10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=layalina.io; spf=pass smtp.mailfrom=layalina.io; dkim=pass (2048-bit key) header.d=layalina-io.20230601.gappssmtp.com header.i=@layalina-io.20230601.gappssmtp.com header.b=wwwFuAlg; arc=none smtp.client-ip=209.85.128.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=layalina.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=layalina.io Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=layalina-io.20230601.gappssmtp.com header.i=@layalina-io.20230601.gappssmtp.com header.b="wwwFuAlg" Received: by mail-wm1-f50.google.com with SMTP id 5b1f17b1804b1-40eebe7767cso26749165e9.1 for ; Mon, 29 Jan 2024 16:05:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=layalina-io.20230601.gappssmtp.com; s=20230601; t=1706573126; x=1707177926; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=YxbSifhVqIOt2/m5QZSeFQNg25CWOD22Pv4LfmhthMA=; b=wwwFuAlgXdGlNk/Fd8yxAyxoqzRYrM88nLXFzcu/ZGDxpxe3Qd1/idUSwldAqTOWoI 1Vbz6lN5D0qiBNR9BSW7PGi6bIr2cTDddmaO4w+Swh7ZLAL8I9pIbp3sfXi47fDUNIRC e7kDFfRLtAD13KLWMwP79Ph7ISRDRmyPTFOqTn0j3fy6DhOnIZuPbLIAmKTUJSkK3ceS 8+xy+3aFuE4tzYaoPsIg9rb3kdH8V/QiiAZpCNHCKae0KkhXMkVErya2frTd+S6lam4a n8ulkBTAu/Jf9A9MNh5OmUGCOk/v/2kkrXSnn9aGqYVGLZ7qop6S9cTLDYY3vHlWVI6B mF9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706573126; x=1707177926; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=YxbSifhVqIOt2/m5QZSeFQNg25CWOD22Pv4LfmhthMA=; b=xSYQFd5dYu0M1W8v5aGBUFMiob88CDr/Vn8NsyMautUocBDkiD9k1252BUAk/cosWC 7lDJ9s9fKYYSj6hcMPmm92xu/z6vNf06NYGFX1vGaPLYfnwBsGrWuMczNDVhRhgDIw5K i6NajbP5qiItlWyUkQ59oJUX9AYya63TZoO56ZC968YBGEcMLnlz7ngmoge1PkRj/N3n huYcDASyl2dRDVj2/UCdhhAxcMdyCprNAZ8Od+Jgc99XiWUOyEQTaxtM8hTSQXevFPRu 5bOqmaTnZWkflNPqLO2SlHHQggbyvGzXEyX43x2o+sOl779h39nz7R1Hv6+MiX0Tmkhk pHOQ== X-Gm-Message-State: AOJu0YyK78fecAoVQEJg2A9rO5oSU6nKLVxfpI5gVLBUCK1nUUR0kAHS eP1t8o0NtaumKyjj3UQg1MMazIELC9Fj1cGfnlG9Yrm8pnQfFdo45q9xRwEeZCI= X-Google-Smtp-Source: AGHT+IEcOm4ToE+OjMANypBdoNmKfiC7rumN1mFFCPVcffivoLtpNe7xAo25vCDii/5hc1czCprBwQ== X-Received: by 2002:a05:600c:4654:b0:40e:b29c:7103 with SMTP id n20-20020a05600c465400b0040eb29c7103mr5917032wmo.8.1706573126220; Mon, 29 Jan 2024 16:05:26 -0800 (PST) Received: from airbuntu ([213.122.231.14]) by smtp.gmail.com with ESMTPSA id n6-20020a05600c500600b0040e3488f16dsm11277752wmr.12.2024.01.29.16.05.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jan 2024 16:05:25 -0800 (PST) Date: Tue, 30 Jan 2024 00:05:24 +0000 From: Qais Yousef To: Vincent Guittot Cc: linux@armlinux.org.uk, catalin.marinas@arm.com, will@kernel.org, sudeep.holla@arm.com, rafael@kernel.org, viresh.kumar@linaro.org, agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, lukasz.luba@arm.com, rui.zhang@intel.com, mhiramat@kernel.org, daniel.lezcano@linaro.org, amit.kachhap@gmail.com, corbet@lwn.net, gregkh@linuxfoundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v4 1/5] cpufreq: Add a cpufreq pressure feedback for the scheduler Message-ID: <20240130000524.4dlivtwn427csjj5@airbuntu> References: <20240109164655.626085-1-vincent.guittot@linaro.org> <20240109164655.626085-2-vincent.guittot@linaro.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240109164655.626085-2-vincent.guittot@linaro.org> On 01/09/24 17:46, Vincent Guittot wrote: > Provide to the scheduler a feedback about the temporary max available > capacity. Unlike arch_update_thermal_pressure, this doesn't need to be > filtered as the pressure will happen for dozens ms or more. > > Signed-off-by: Vincent Guittot > --- > drivers/cpufreq/cpufreq.c | 36 ++++++++++++++++++++++++++++++++++++ > include/linux/cpufreq.h | 10 ++++++++++ > 2 files changed, 46 insertions(+) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 44db4f59c4cc..f4eee3d107f1 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -2563,6 +2563,40 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) > } > EXPORT_SYMBOL(cpufreq_get_policy); > > +DEFINE_PER_CPU(unsigned long, cpufreq_pressure); > + > +/** > + * cpufreq_update_pressure() - Update cpufreq pressure for CPUs > + * @policy: cpufreq policy of the CPUs. > + * > + * Update the value of cpufreq pressure for all @cpus in the policy. > + */ > +static void cpufreq_update_pressure(struct cpufreq_policy *policy) > +{ > + unsigned long max_capacity, capped_freq, pressure; > + u32 max_freq; > + int cpu; > + > + cpu = cpumask_first(policy->related_cpus); > + max_freq = arch_scale_freq_ref(cpu); > + capped_freq = policy->max; > + > + /* > + * Handle properly the boost frequencies, which should simply clean > + * the cpufreq pressure value. > + */ > + if (max_freq <= capped_freq) { > + pressure = 0; > + } else { > + max_capacity = arch_scale_cpu_capacity(cpu); > + pressure = max_capacity - > + mult_frac(max_capacity, capped_freq, max_freq); > + } > + > + for_each_cpu(cpu, policy->related_cpus) > + WRITE_ONCE(per_cpu(cpufreq_pressure, cpu), pressure); Is this WRITE_ONCE() required? I don't see why. But assuming I missed something, better pair it with READ_ONCE() in cpufreq_get_pressure()? Beside that, LGTM Reviewed-by: Qais Yousef > +} > + > /** > * cpufreq_set_policy - Modify cpufreq policy parameters. > * @policy: Policy object to modify. > @@ -2618,6 +2652,8 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, > policy->max = __resolve_freq(policy, policy->max, CPUFREQ_RELATION_H); > trace_cpu_frequency_limits(policy); > > + cpufreq_update_pressure(policy); > + > policy->cached_target_freq = UINT_MAX; > > pr_debug("new min and max freqs are %u - %u kHz\n", > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h > index afda5f24d3dd..b1d97edd3253 100644 > --- a/include/linux/cpufreq.h > +++ b/include/linux/cpufreq.h > @@ -241,6 +241,12 @@ struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy); > void cpufreq_enable_fast_switch(struct cpufreq_policy *policy); > void cpufreq_disable_fast_switch(struct cpufreq_policy *policy); > bool has_target_index(void); > + > +DECLARE_PER_CPU(unsigned long, cpufreq_pressure); > +static inline unsigned long cpufreq_get_pressure(int cpu) > +{ > + return per_cpu(cpufreq_pressure, cpu); > +} > #else > static inline unsigned int cpufreq_get(unsigned int cpu) > { > @@ -263,6 +269,10 @@ static inline bool cpufreq_supports_freq_invariance(void) > return false; > } > static inline void disable_cpufreq(void) { } > +static inline unsigned long cpufreq_get_pressure(int cpu) > +{ > + return 0; > +} > #endif > > #ifdef CONFIG_CPU_FREQ_STAT > -- > 2.34.1 >