From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) (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 3C2923FCB37 for ; Fri, 4 Sep 2026 08:53:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788512040; cv=none; b=hnBxxvio5DtcnmqbSB8K1GfVOXrMUP6qh90Xbb5xtRV0SO5A69qHsiY2qpcOLrQslTLnOrCfXrEAyEevf67YNkpWDMwnSFVjVrY0uWO2gnlHoZsF6H13imjJj+byFHBFhb0KOcAyMiNlkbo9nbZWhrfDC0e8X6lSZmF+mBpeY0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788512040; c=relaxed/simple; bh=ujPoI3WZTYZJvu+8KsGsqjcJJ02tCGGjG7jqVeIHUw0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZQbB/RQslYVfS16r4xwMbmT/LX+1KKhivcXlJI0388zdgTDKdSEA3DE5voLXUTS9U8qyKi1aMoQStJo+Y4dO3T1wZVIIpxxJQHP0ngd/bD3AjBArlIia0tA8e5L+kA7+w18iVybbHel68HFyng/Un0aXbznuNel+c3H6SmEoYX8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=UdscEhvB; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="UdscEhvB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=L8 Sqz3pezr4ceawkMz9qGzXiScCqUayQXqF2L7MGyIc=; b=UdscEhvBHsLKHhHsrX 1gY9f2W8U/+msd5qLjKYDB1ajdYDiGwqkDCgYaSZpDbmZxlS9/Gkl3CLYDNkY08H xCw6SXWushHqJ9lDoIpdId0DuEuOLXm6uCVZ7SVXL3o5w1FfLxr5PzRTtTRmM45O iL00MtHnxfOWe+NwtXo+cT2cE= Received: from localhost (unknown []) by gzsmtp5 (Coremail) with SMTP id QCgvCgCnpR3fhppqbSRxPw--.20264S2; Fri, 04 Sep 2026 16:52:48 +0800 (CST) From: Hui Su To: peterz@infradead.org, mingo@redhat.com, tim.c.chen@linux.intel.com, yu.c.chen@intel.com, kprateek.nayak@amd.com Cc: juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, connoro@google.com, jstultz@google.com, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] sched/cache: Drive cache task tick from execution context Date: Fri, 4 Sep 2026 16:52:44 +0800 Message-ID: <20260904085244.799276-3-sh_def@163.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260904085244.799276-1-sh_def@163.com> References: <20260904085244.799276-1-sh_def@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:QCgvCgCnpR3fhppqbSRxPw--.20264S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxXFyxGw1DWr17XF15uF45Jrb_yoWrJFWUpa yDWa17Jr4kJayjgFy8Z3ykAr13G3sava43KFs5Jw4Fkr1rtw1Y9Fyjq3W2vr4Yvr10ka42 vr4j9347Gr1jgr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jjHqcUUUUU= X-CM-SenderInfo: xvkbvvri6rljoofrz/xtbC6QAbemqahuCAeAAA3m Cache-aware scheduling accounts CPU runtime to the mm of the task actually executing. update_se() passes the execution task to account_mm_sched() for this purpose. With proxy execution, however, sched_tick() invokes task_tick() for the scheduling context in rq->donor. task_tick_cache() is currently called from task_tick_fair(), so it is skipped when a fair task executes on behalf of an RT or deadline donor. In that case account_mm_sched() continues to advance runtime accounting for rq->curr, while task_tick_cache() does not advance the corresponding mm scan epoch. Once the epoch becomes stale, account_mm_sched() can invalidate the mm's preferred LLC. Move cache tick handling into sched_tick_exec_ctx(), alongside NUMA tick handling, and run it when the execution context is a fair task. Use the same helper from sched_tick() and sched_tick_remote() so both tick paths handle the execution context consistently. Keep the remaining task_tick_fair() bookkeeping with its task argument, since misfit, overutilized, and core scheduling state belong to the scheduling context. Fixes: df0d98475954 ("sched/cache: Introduce infrastructure for cache-aware load balancing") Suggested-by: Tim Chen Signed-off-by: Hui Su --- kernel/sched/core.c | 1 + kernel/sched/fair.c | 11 +++++++---- kernel/sched/sched.h | 1 + 3 files changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4db55e4ace9e..7b8d4b06207d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5771,6 +5771,7 @@ static void sched_tick_exec_ctx(struct rq *rq) if (static_branch_unlikely(&sched_numa_balancing)) task_tick_numa(rq, curr); + task_tick_cache(rq, curr); } /* diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 55f0460e4ae3..c519bb193850 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1774,7 +1774,7 @@ void account_mm_sched(struct rq *rq, struct task_struct *p, s64 delta_exec) } } -static void task_tick_cache(struct rq *rq, struct task_struct *p) +void task_tick_cache(struct rq *rq, struct task_struct *p) { struct callback_head *work = &p->cache_work; struct mm_struct *mm = p->mm; @@ -1996,7 +1996,7 @@ static inline void account_mm_sched(struct rq *rq, struct task_struct *p, void init_sched_mm(struct task_struct *p) { } -static void task_tick_cache(struct rq *rq, struct task_struct *p) { } +void task_tick_cache(struct rq *rq, struct task_struct *p) { } static inline int get_pref_llc(struct task_struct *p, struct mm_struct *mm) @@ -15042,8 +15042,11 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) if (queued) return; - task_tick_cache(rq, curr); - + /* + * Misfit, overutilized and core scheduling state belong to the + * scheduling context, and therefore stay with @curr rather than + * rq->curr. See sched_tick_exec_ctx() for execution-context work. + */ update_misfit_status(curr, rq); check_update_overutilized_status(task_rq(curr)); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4d619f272b15..5d1f5ee47bf1 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -4153,6 +4153,7 @@ void sched_domains_free_llc_id(int cpu); extern void init_sched_mm(struct task_struct *p); void task_tick_numa(struct rq *rq, struct task_struct *p); +void task_tick_cache(struct rq *rq, struct task_struct *p); extern u64 avg_vruntime(struct cfs_rq *cfs_rq); extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se);