From patchwork Fri Dec 8 00:23:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qais Yousef X-Patchwork-Id: 13484504 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="x+BhzZ6V" Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35ADBC6 for ; Thu, 7 Dec 2023 16:24:09 -0800 (PST) Received: by mail-wm1-x329.google.com with SMTP id 5b1f17b1804b1-40c32df9174so1799675e9.3 for ; Thu, 07 Dec 2023 16:24:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=layalina-io.20230601.gappssmtp.com; s=20230601; t=1701995047; x=1702599847; 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=4hmu4GR1Tf24zDfNQg/5SjNdB/QFzSeUZxk8HyYC52U=; b=x+BhzZ6VtGPBQFltDUsIdkVfWUh1AG8Qdn8SLD2E/8UQ7ee58SP79CSpA/Pv4BVVh5 rpZvTDUQo5GjiQ2GTc9lJx5hTiIOHuK9D7VjixxgTDFBNdLi3vNzmVXD4f1Yjng5mE98 Q4POqOxubMOO8smHCX2dGZYTCZVz3qi3AUBvrkjFygVZFpIkVbgaQ92gJHXHVZpx6uyA xPAzbfpgOK6aXQaVxbd1hIqL4mYXL9wMiNjA2zLTq/60dthzOj+qTlsE3lHGaX2zTyCI hzHYUM7TqpGUCctXCu5IdF+ugivfruAgOEwQgOIQrFrSIGxQ5yeGWEaFDvMHqwVML1sW GjVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701995047; x=1702599847; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4hmu4GR1Tf24zDfNQg/5SjNdB/QFzSeUZxk8HyYC52U=; b=UIbUyCFrHsSt/zZG4/IYe7RhiUyMnTmY/zCxVs19BzpxsyHVob528Q5qCto3CF3iea G4cAyH7B+UOH0EisYa91mOzwqAyqtRA5pxuY4Lj2aKIQP52Pr7db/dJi0Bgct5rLqc36 OJIl5MWTgQAa9kyppRR6C//owZ0T3a2dhPmbOzlkOKLb7T9DjplLMyqeXK1ItEtxMbjt 15oJX+cX03/1ycOq2YZ9UP5z2PUFPJBAzTwiBl+/MEZsMwimSOGWWGZ5udx2EtOqpagB 7nlJarrVTLzOtLapAQITNBUDZWo++T64hpssaMY3Z+11pAOjlQI0Jfb2LqDvCbnMChVV a2gw== X-Gm-Message-State: AOJu0YyXRkbkiVEtHIugw3/hYGBhLUrg2C3/5tdFGcK/6Az1oAySNwd3 ZlKM7Y4L8w3NP/QXUKmndJKxTQ== X-Google-Smtp-Source: AGHT+IEDkE6xFmQ45NVfGlGxefY7HBAhSTWDgMehJ17Ql0RmMpqkVzJDaZNH0S70STgK37Gtbrc9Yg== X-Received: by 2002:a05:600c:a388:b0:40c:2c51:d78b with SMTP id hn8-20020a05600ca38800b0040c2c51d78bmr522596wmb.209.1701995047752; Thu, 07 Dec 2023 16:24:07 -0800 (PST) Received: from airbuntu.. (host109-153-232-45.range109-153.btcentralplus.com. [109.153.232.45]) by smtp.gmail.com with ESMTPSA id u17-20020a05600c19d100b0040c1c269264sm3339653wmq.40.2023.12.07.16.24.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Dec 2023 16:24:07 -0800 (PST) From: Qais Yousef To: Ingo Molnar , Peter Zijlstra , "Rafael J. Wysocki" , Viresh Kumar , Vincent Guittot , Dietmar Eggemann Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Lukasz Luba , Wei Wang , Rick Yiu , Chung-Kai Mei , Qais Yousef Subject: [PATCH v2 3/8] sched/pelt: Add a new function to approximate the future util_avg value Date: Fri, 8 Dec 2023 00:23:37 +0000 Message-Id: <20231208002342.367117-4-qyousef@layalina.io> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231208002342.367117-1-qyousef@layalina.io> References: <20231208002342.367117-1-qyousef@layalina.io> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Given a util_avg value, the new function will return the future one given a runtime delta. This will be useful in later patches to help replace some magic margins with more deterministic behavior. Signed-off-by: Qais Yousef (Google) --- kernel/sched/pelt.c | 22 +++++++++++++++++++++- kernel/sched/sched.h | 2 ++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c index 63b6cf898220..81555a8288be 100644 --- a/kernel/sched/pelt.c +++ b/kernel/sched/pelt.c @@ -466,4 +466,24 @@ int update_irq_load_avg(struct rq *rq, u64 running) return ret; } -#endif +#endif /* CONFIG_HAVE_SCHED_AVG_IRQ */ + +/* + * Approximate the new util_avg value assuming an entity has continued to run + * for @delta us. + */ +unsigned long approximate_util_avg(unsigned long util, u64 delta) +{ + struct sched_avg sa = { + .util_sum = util * PELT_MIN_DIVIDER, + .util_avg = util, + }; + + if (unlikely(!delta)) + return util; + + accumulate_sum(delta, &sa, 1, 0, 1); + ___update_load_avg(&sa, 0); + + return sa.util_avg; +} diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0da3425200b1..7e5a86a376f8 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3002,6 +3002,8 @@ unsigned long sugov_effective_cpu_perf(int cpu, unsigned long actual, unsigned long min, unsigned long max); +unsigned long approximate_util_avg(unsigned long util, u64 delta); + /* * DVFS decision are made at discrete points. If CPU stays busy, the util will * continue to grow, which means it could need to run at a higher frequency