From nobody Tue Dec 2 02:04:16 2025 Received: from mail-lj1-f174.google.com (mail-lj1-f174.google.com [209.85.208.174]) (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 9E7063446AB for ; Fri, 21 Nov 2025 10:03:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763719428; cv=none; b=OPFX9SXwF6Lu23fJAo72Kz5Kt3CSMdudaaeZj58l4wBCYZPcpLBipIeG1kf7tVliQFwfoWISDsometm4lar08saTf0o2UfXW1gixlZqO+6oE+cK90Q60331UCjEOqFVSQRxaUgyI5HT+qZyi9vyc8UbyPBmtf29R/mQgdrYfmBU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763719428; c=relaxed/simple; bh=K3MxTv90njG8ObrSi5Q0KC7YVJRI9TsyV3oJl0B8R7U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sq8Uj502C247r1UD+KfKxiw49o+caKxi0Ai47xQ+GLy2aUzwKKkZUqLt7HySfBmJmm6cnflPhWlh5hJIqPXSJD0CyboqOEjrUe2FGnMVMHPHRxNEza8vZ+0FvkVDflXGZKqpc5RUmrP01ElJR9eMVzpggrtWMd20FiU/Wu0pcB8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=qIAeuc8k; arc=none smtp.client-ip=209.85.208.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="qIAeuc8k" Received: by mail-lj1-f174.google.com with SMTP id 38308e7fff4ca-37b996f6b28so15526291fa.3 for ; Fri, 21 Nov 2025 02:03:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1763719423; x=1764324223; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=wc4a0PHuDmrPqR556Ou7IBfq8uevDM9S8fV5JzT1uPs=; b=qIAeuc8kArqRHlcMD++i7dCCQTOp7fQ4pyhPodrkpVYGfk+FR7/AslYHzg7Bg/2QzN /X/5opMVqvVXhsJbCwNsRpHGiSsiCbz6GTtF4Xa1zcT4sda+u8Ms7/UKNsKLu862F288 uMAHYEu1Wis9cFBTneJ71FEi9mYy5atj3vgpejcAP63MfPgbgmBUzob4HHDzzE0BHFr9 XjmoMekOF4An6IsA9xLe2QjoP3oBmpgUBcprTUgbT385e9jPfUiZLsqXx3Mci2k1GjF0 xk+xxFh8yODFYfgGm1oS9aOoid3r+W62hB4lFA9EvryfWrd6Y4KOIHECyoR7jgBVOEZL Z2dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763719423; x=1764324223; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=wc4a0PHuDmrPqR556Ou7IBfq8uevDM9S8fV5JzT1uPs=; b=FIZ0wd+0qaWfDcqZqvfJqzo+y7FiwMGHZ48T3jruoWs6I437zxmIvEYux6JN4vLMXW Aq7uniS5piGs5GmI11CoIb24XDd4IgSVal1SL1q3yu7K9KkrOcRasQhhTccfE4kDTyRY i5vi5WrBhXDltFJTyq0SIfx8dLiVhygZYDN4HJCSHj0g3jSYGdv36b23jt4VA0d/o2O3 0cvVfeAe+07OLNrsqlOfcbOkDpcGn8I969MlzKPb3MZWWXRWM156JqKKh2S9koPXHVkS q+RzHhNz93GeB3pj3lwrh9X2L5c4EWkDfD/mWGKZ92dRdjNFgqXxAAXnfbmmNZN5shf4 SBRQ== X-Forwarded-Encrypted: i=1; AJvYcCWW6TjAdSzkdme8kudu9dO3AR0D4HgMtVoCTTreoeJNLIzsHOqk+vbQTA0gFKAcDcKe1aYShwFNz0Yckd8=@vger.kernel.org X-Gm-Message-State: AOJu0YyUwoubHaf/0NM/UvVPtR1y0vv5UNSNb8inRcog+mNdPBi+y6jP DbQ9xBztLaCt0vu/MwlgXOuWIWETGUTJeQD14wjEdY9KS0ZBXLyWL0R3Ncf5H1jB4LA= X-Gm-Gg: ASbGncua0RmbeVm47xb5cSWfKoqGVyUyjmMvK6WFLYWfe7QENLSgNcBru4ewooxdxTg SeGA3K52yHAN9Ce5slIeDde7skTELrwOzLL8Irg7hXwP1Yfs4I8L3+ev4z551QtTnfqn2NG/fGw eGfimWpiDBLrutL+R+eEr64XNLmHeq+1kUoKICZRaRGZkdFXzZTv8ba7H3aEDR7LNJoC09HEwE6 KiW6WxSgkp5EmxMUZNZHa++VS+vTM2hYAi8/oQIX3eSZpqe4vSziZte97h5awwpyl7oOymdSuvw ylRnUQbYG7zfrQf8bHeBmLWwdr9xIURaZ8ZZXd7pTWzcI9BB2ol6fsR0EXIKQtg/xm3U0ufU8CW DQOYv/WCPL97EeHr2/OFEyHOTKVdBh8OcRDvb1dwxbIT+H9tcpnXjac29xdx0x5O/mMNXJJyr4+ q2TqpjJsv64Tq4BRa27wUCioqpoaZUoKyUloMYGGEIWr7irTeZeDh6eUOEMqWy X-Google-Smtp-Source: AGHT+IHqTYQeVPe88r/RF7U4BUGHstho8L55Y/bCN09qnK5NUE1fa5dy2Zd0wMboPTMi78eqXpiy+w== X-Received: by 2002:a05:651c:25c5:10b0:37b:a4e2:43fa with SMTP id 38308e7fff4ca-37cd92bf090mr3845761fa.43.1763719422602; Fri, 21 Nov 2025 02:03:42 -0800 (PST) Received: from uffe-tuxpro14.. (h-178-174-189-39.A498.priv.bahnhof.se. [178.174.189.39]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-37cc6b597b2sm11056181fa.12.2025.11.21.02.03.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Nov 2025 02:03:41 -0800 (PST) From: Ulf Hansson To: "Rafael J . Wysocki" , linux-pm@vger.kernel.org Cc: Vincent Guittot , Peter Zijlstra , Kevin Hilman , Pavel Machek , Len Brown , Daniel Lezcano , Maulik Shah , Prasad Sodagudi , Dhruva Gole , Deepti Jaggi , Ulf Hansson , linux-kernel@vger.kernel.org Subject: [PATCH v3 4/6] sched: idle: Respect the CPU system wakeup QoS limit for s2idle Date: Fri, 21 Nov 2025 11:03:10 +0100 Message-ID: <20251121100315.316300-5-ulf.hansson@linaro.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251121100315.316300-1-ulf.hansson@linaro.org> References: <20251121100315.316300-1-ulf.hansson@linaro.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" A CPU system wakeup QoS limit may have been requested by user space. To avoid breaking this constraint when entering a low power state during s2idle, let's start to take into account the QoS limit. Acked-by: Peter Zijlstra (Intel) Signed-off-by: Ulf Hansson Reviewed-by: Dhruva Gole --- Changes in v3: - Updated commit message and added ack from Peter. Changes in v2: - Rework the code to take into account the failure/error path, when we don't find a s2idle specific state. --- drivers/cpuidle/cpuidle.c | 12 +++++++----- include/linux/cpuidle.h | 6 ++++-- kernel/sched/idle.c | 12 +++++++----- 3 files changed, 18 insertions(+), 12 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 56132e843c99..c7876e9e024f 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -184,20 +184,22 @@ static noinstr void enter_s2idle_proper(struct cpuidl= e_driver *drv, * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. * @drv: cpuidle driver for the given CPU. * @dev: cpuidle device for the given CPU. + * @latency_limit_ns: Idle state exit latency limit * * If there are states with the ->enter_s2idle callback, find the deepest = of * them and enter it with frozen tick. */ -int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device= *dev) +int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device= *dev, + u64 latency_limit_ns) { int index; =20 /* - * Find the deepest state with ->enter_s2idle present, which guarantees - * that interrupts won't be enabled when it exits and allows the tick to - * be frozen safely. + * Find the deepest state with ->enter_s2idle present that meets the + * specified latency limit, which guarantees that interrupts won't be + * enabled when it exits and allows the tick to be frozen safely. */ - index =3D find_deepest_state(drv, dev, U64_MAX, 0, true); + index =3D find_deepest_state(drv, dev, latency_limit_ns, 0, true); if (index > 0) { enter_s2idle_proper(drv, dev, index); local_irq_enable(); diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index a9ee4fe55dcf..4073690504a7 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -248,7 +248,8 @@ extern int cpuidle_find_deepest_state(struct cpuidle_dr= iver *drv, struct cpuidle_device *dev, u64 latency_limit_ns); extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, - struct cpuidle_device *dev); + struct cpuidle_device *dev, + u64 latency_limit_ns); extern void cpuidle_use_deepest_state(u64 latency_limit_ns); #else static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, @@ -256,7 +257,8 @@ static inline int cpuidle_find_deepest_state(struct cpu= idle_driver *drv, u64 latency_limit_ns) {return -ENODEV; } static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, - struct cpuidle_device *dev) + struct cpuidle_device *dev, + u64 latency_limit_ns) {return -ENODEV; } static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) { diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index c39b089d4f09..c1c3d0166610 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -131,12 +131,13 @@ void __cpuidle default_idle_call(void) } =20 static int call_cpuidle_s2idle(struct cpuidle_driver *drv, - struct cpuidle_device *dev) + struct cpuidle_device *dev, + u64 max_latency_ns) { if (current_clr_polling_and_test()) return -EBUSY; =20 - return cpuidle_enter_s2idle(drv, dev); + return cpuidle_enter_s2idle(drv, dev, max_latency_ns); } =20 static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device = *dev, @@ -205,12 +206,13 @@ static void cpuidle_idle_call(void) u64 max_latency_ns; =20 if (idle_should_enter_s2idle()) { + max_latency_ns =3D cpu_wakeup_latency_qos_limit() * + NSEC_PER_USEC; =20 - entered_state =3D call_cpuidle_s2idle(drv, dev); + entered_state =3D call_cpuidle_s2idle(drv, dev, + max_latency_ns); if (entered_state > 0) goto exit_idle; - - max_latency_ns =3D U64_MAX; } else { max_latency_ns =3D dev->forced_idle_latency_limit_ns; } --=20 2.43.0