From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D4D112E7E; Mon, 25 Mar 2024 17:06:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711386391; cv=none; b=GwmW7SlLikBXCNebMaR3KYNPoeUNVPz09NbkxEFO6hnYnSRtYZ10i7n06kO6l3LxF4ijxcN2Fe4R/37Yi4PQ53hripSv3phVzWt+4RAPOkbAdjVTD2deMv7rfDUMwIB3Tt3NgXawGUBfFhh1ulLRZBXwIUHKoPPYcOqutEqAVrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711386391; c=relaxed/simple; bh=wxRwgptLJPCrasWZqmI2ge30NFdmDWXQzxRENlojAp0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XWcAJmAZIsJvVDuO7yFIBuUwyYyUC9hl6ZE+hs5yJSbrZOLQmdEwWDKADVzpU9k3/KovyYlTW4au7WauzMDn6XasOvTLh8HV0/QiheT8XiW4O2m3OU9drTU3eH/BFY2SYyYTFO5agTj4hAMYApEaM/50MwQLUwqozH4DdiEp3+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=fail (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=Zu74X5Bk reason="signature verification failed"; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="Zu74X5Bk" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 5.4.0) id 91d91d94e0e35301; Mon, 25 Mar 2024 18:06:27 +0100 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id 9F4D266BCFE; Mon, 25 Mar 2024 18:06:26 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1711386387; bh=wxRwgptLJPCrasWZqmI2ge30NFdmDWXQzxRENlojAp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Zu74X5BktZAcuMVOCmZMP1EHqXisjLO/RZ0h/7b3aHTfUqFRpZN0h5iVFiIYGPJzM 0FE7nLhjO9XXGPu5pNeUAYud7aIT8jBOj/k0xEBg5pCc0UxHmIUFgf4GCQBIIuzR/O Qi28q+qzRvnphRmYJzdyxdn/OVy8bZM0QQ7ZaIZzQ5icR0ITc8b0ddVJhPI8exFHBw z3HGTzzK0kKenGVqO1r3ZQ3GMBdqbvGzQJrvuXKWmQZT1RmK49Yma22QbUjZDt2C0u NgHQ0o3nAEYYOOSkqt3SrGUCXUABXlayuC0/VVodd3IFq7TZZbet3aEMHtfIOpR33P DrVOjnOCGsSHQ== From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Srinivas Pandruvada Subject: [PATCH v1 4/6] cpufreq: intel_pstate: Read global.no_turbo under READ_ONCE() Date: Mon, 25 Mar 2024 18:04:24 +0100 Message-ID: <22244552.EfDdHjke4D@kreacher> In-Reply-To: <13494237.uLZWGnKmhe@kreacher> References: <13494237.uLZWGnKmhe@kreacher> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="UTF-8" X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvledrudduuddgfeehucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppeduleehrddufeeirdduledrleegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepudelhedrudefiedrudelrdelgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohepfedprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehsrhhinhhivhgrshdrphgrnhgurhhuvhgruggrsehlihhnuhigrdhinhhtvghlrdgtohhm X-DCC--Metrics: v370.home.net.pl 1024; Body=3 Fuz1=3 Fuz2=3 From: Rafael J. Wysocki Because global.no_turbo is generally not read under intel_pstate_driver_lock make store_no_turbo() use WRITE_ONCE() for updating it (this is the only place at which it is updated except for the initialization) and make the majority of places reading it use READ_ONCE(). Also remove redundant global.turbo_disabled checks from places that depend on the 'true' value of global.no_turbo because it can only be 'true' if global.turbo_disabled is also 'true'. Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -1296,7 +1296,7 @@ static ssize_t store_no_turbo(struct kob goto unlock_driver; } - global.no_turbo = no_turbo; + WRITE_ONCE(global.no_turbo, no_turbo); mutex_lock(&intel_pstate_limits_lock); @@ -1748,7 +1748,7 @@ static u64 atom_get_val(struct cpudata * u32 vid; val = (u64)pstate << 8; - if (global.no_turbo && !global.turbo_disabled) + if (READ_ONCE(global.no_turbo) && !global.turbo_disabled) val |= (u64)1 << 32; vid_fp = cpudata->vid.min + mul_fp( @@ -1913,7 +1913,7 @@ static u64 core_get_val(struct cpudata * u64 val; val = (u64)pstate << 8; - if (global.no_turbo && !global.turbo_disabled) + if (READ_ONCE(global.no_turbo) && !global.turbo_disabled) val |= (u64)1 << 32; return val; @@ -2211,7 +2211,7 @@ static inline int32_t get_target_pstate( sample->busy_scaled = busy_frac * 100; - target = global.no_turbo || global.turbo_disabled ? + target = READ_ONCE(global.no_turbo) ? cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; target += target >> 2; target = mul_fp(target, busy_frac); @@ -2473,7 +2473,7 @@ static void intel_pstate_clear_update_ut static int intel_pstate_get_max_freq(struct cpudata *cpu) { - return global.turbo_disabled || global.no_turbo ? + return READ_ONCE(global.no_turbo) ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; } @@ -2610,7 +2610,7 @@ static void intel_pstate_verify_cpu_poli if (hwp_active) { intel_pstate_get_hwp_cap(cpu); - max_freq = global.no_turbo || global.turbo_disabled ? + max_freq = READ_ONCE(global.no_turbo) ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; } else { max_freq = intel_pstate_get_max_freq(cpu);