From nobody Sun Feb 8 11:21:17 2026 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (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 A5100C133 for ; Sat, 20 Jul 2024 05:12:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721452380; cv=none; b=NWSwnL7Qi/KXCY+GIETNEFoBi8+LhLmFamOliebWmFGQeh6FQnk6PB+mXVhWsDO2ZwqCl42zttmYYMIeHOokcPxK9JINS7BP1m/s5YmysW0e4sw58nrTdllSXmOjlQ+zFkCMKq4EGcYAS4egIIv54CgbD0F4KBVIsiLb8MW9Scg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721452380; c=relaxed/simple; bh=BcpCgPgDTGzwxMzLDD/Uq6UrofQQQMlB6ckWQrsLcCc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=YXY6uCcW43Y8U4j/vTvcdGfpXehbhyHSW6BJE+ebLRvtn2Jz1HykytjW31T1VW3cDMr5FHrQRPdY1bLKOxisZrMQE3nKlqFaluAfuXLrmbv9I7Ik/HTyhu1mG8SExuxe3B1TaK9tV8nX5NN9DdjVm5YPH47FSB+DuAf/mTAs76s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=cLXLlEOm; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="cLXLlEOm" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-70d138e06e3so19198b3a.2 for ; Fri, 19 Jul 2024 22:12:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1721452378; x=1722057178; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=oQcmet6Zvq2ElvCY9TE00CST6ri9ogoQlzos7cz+E3E=; b=cLXLlEOm/ly/GFPXUF1JNsPOY+wlE8KHxkvbzKgK/s8Vn1KVxMFKfVfW847ru8b/ug XzZjAOntx+t07gHt2JIWEQbFP0Ht43qZpL+iUc5ui9yP+eBHRpSO45ZDcAAcX6M0bWSH kRClofNRJwDRAD4lxKhxFbTs29Ze/Z/fOAGuf0SxvHhuR59gnaxX2Npc8lLfFezcFZsf 3IsdhtIXGna1g9YKIPzhdMQlD0HtskztipURmi5NpLy8s1mNw75VwPdlTyCMCLtNb/cG lnA1Z2Qqik2hQA4BZ/BO9qfnQpXlmaNRZkjfJmH6cr84uyH+geaZ9uI/Xqpezi/Uaoti iv4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721452378; x=1722057178; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=oQcmet6Zvq2ElvCY9TE00CST6ri9ogoQlzos7cz+E3E=; b=S0ymYUKI7nsaEwDSn9hO0g1a0Ufc8gt4KX0h97QV6Q7UNgl63eA589OAjALHVH7PrE 3reFP0gmkbcORWhWfAIrr3UuoAcECEa9X8AWQc153dj4P3GkrvuhEq8/M0mjHvIwHTN5 1zY4UhoSov5slM4OhpfbR1OSV6dHns+BQsdq1VUgG10tPiGwQP/23agknAcHIl1ErhQX S2drx1adTeRxod04v3SDSDWmfBBmzHUh3fmaC+2R3OI8B+2rqp/u+TAS0nyRNHIDBBpa 7nTm4ve/VVlyPGXvekjCpwjnRfxgzb/JSHKY19nxKm68yzncE9RNiDMpQPjzIpaOyy7a +GXg== X-Forwarded-Encrypted: i=1; AJvYcCVVndcRweKmint0jf2TbE+BVGBE+iuA43Jg+AoIJLrmlgxZzRxK1HGSmbYdagS8Ly7Su0rISpi/odgX7m66X/aolKkn50n0hzSf6Mqp X-Gm-Message-State: AOJu0YyiP/JNZbRECY1soZDwrtzZXF1vDwTF09w9jugb3k0PJp9nJLDP k2nS/euZ0sp4lWqx4zNFXZSrVVMRelzrDRD1moNhsR/IBW4V3GesSRn68VxBDXg= X-Google-Smtp-Source: AGHT+IFlqrZW+TMwqiWlSqHLwRnv7PK63sUTVn1u1BUsimoT+xLCOS+ogHTvIXJKT30IEZij3aIOKQ== X-Received: by 2002:a05:6a21:3390:b0:1c1:e75a:5504 with SMTP id adf61e73a8af0-1c42287f402mr2780830637.15.1721452377890; Fri, 19 Jul 2024 22:12:57 -0700 (PDT) Received: from YGFVJ29LDD.bytedance.net ([139.177.225.235]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2cb77540a6esm3744207a91.54.2024.07.19.22.12.52 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 19 Jul 2024 22:12:57 -0700 (PDT) From: Chuyi Zhou To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com Cc: chengming.zhou@linux.dev, linux-kernel@vger.kernel.org, Chuyi Zhou Subject: [PATCH v2] sched/fair: Sync se's load_avg with cfs_rq in reweight_task Date: Sat, 20 Jul 2024 13:12:48 +0800 Message-Id: <20240720051248.59608-1-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.37.0 (Apple Git-136) 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" In reweight_task(), there are two situations: 1. The task was on_rq, then the task's load_avg is accurate because we synchronized it with cfs_rq through update_load_avg() in dequeue_task(). 2. The task is sleeping, its load_avg might not have been updated for some time, which can result in inaccurate dequeue_load_avg() in reweight_entity(). This patch solves this by using update_load_avg() to synchronize the load_avg of se with cfs_rq. For tasks were on_rq, since we already update load_avg to accurate values in dequeue_task(), this change will not have other effects due to the short time interval between the two updates. Signed-off-by: Chuyi Zhou Reviewed-by: K Prateek Nayak --- Changes in v2: - change the description in commit log. - use update_load_avg() in reweight_task() rather than in reweight_entity suggested by chengming. - Link to v1: https://lore.kernel.org/lkml/20240716150840.23061-1-zhouchuyi= @bytedance.com/ --- kernel/sched/fair.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9057584ec06d..b1e07ce90284 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3835,12 +3835,15 @@ static void reweight_entity(struct cfs_rq *cfs_rq, = struct sched_entity *se, } } =20 +static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_ent= ity *se, int flags); + void reweight_task(struct task_struct *p, const struct load_weight *lw) { struct sched_entity *se =3D &p->se; struct cfs_rq *cfs_rq =3D cfs_rq_of(se); struct load_weight *load =3D &se->load; =20 + update_load_avg(cfs_rq, se, 0); reweight_entity(cfs_rq, se, lw->weight); load->inv_weight =3D lw->inv_weight; } --=20 2.20.1