From nobody Tue Oct 7 11:57:54 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 39B01FC1D for ; Thu, 10 Jul 2025 07:11:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752131495; cv=none; b=AcJmbB0cTYTBZaoq5b6pijdOcJm/QWuaXCsff7gjsyauFZWPq+t5OLGpifcpeCDcQLvOnzrAs7KI+/Bs247ADgOB5Dr9pN55TbvzCgkdtdHLIs/tZG2G7ni9GTFvzYBWS+n/olr2Up92AACZe9mVAb1R9VRDz7IKLrS5nx8c++I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752131495; c=relaxed/simple; bh=23RALKBWs4xi/fpqSsULx8OkRH5EOi8YXbwhvUqLkM4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=CTCM2T8P6FfTgLlCS84N2NUcg6XBfzYUtxujdRzI/tbkGFGlgQyzVetLbYFZeQrXlImwZxYVYuMNPOanxPLHyU09dUeVEUXaKeRUdcfvgBmxEz7uK+jOGtHCLeLMVm4ty2NTRDR5AUbhxj5xvrgNpUvsgzHB7FXzD4i8fgjN58k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 089421C0A; Thu, 10 Jul 2025 00:11:21 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5429F3F66E; Thu, 10 Jul 2025 00:11:30 -0700 (PDT) From: Yeoreum Yun To: hannes@cmpxchg.org, surenb@google.com, peterz@infradead.org, mingo@redhat.com, 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: linux-kernel@vger.kernel.org, Yeoreum Yun Subject: [PATCH v3] psi: fix avg trigger being fired unexpectedly. Date: Thu, 10 Jul 2025 08:11:28 +0100 Message-Id: <20250710071128.1637175-1-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 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" commit 915a087e4c473("psi: Fix trigger being fired unexpectedly at initial") fixes unexpected event fired when group->total accumulated for PSI_POLL. But, for PSI_AVGS, win->value should be initialized with group->total[PSI_A= VGS]. Moreover, to get exact initial value for win->value, it should be set under each trigger lock to avoid concurrent changes to group->total[]. Signed-off-by: Yeoreum Yun Acked-by: Suren Baghdasaryan --- Patch History =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D from v2 to v3: - change author - rebase to v6.16-rc5 - https://lore.kernel.org/all/20240226211237.48415-1-ppbuk5246@gmail.com/ from v1 to v2: - fix commit message - https://lore.kernel.org/all/20240226194642.47530-1-ppbuk5246@gmail.com/= #t --- kernel/sched/psi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index ad04a5c3162a..00cf7acb5eb3 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1337,9 +1337,6 @@ struct psi_trigger *psi_trigger_create(struct psi_gro= up *group, char *buf, t->state =3D state; t->threshold =3D threshold_us * NSEC_PER_USEC; t->win.size =3D window_us * NSEC_PER_USEC; - window_reset(&t->win, sched_clock(), - group->total[PSI_POLL][t->state], 0); - t->event =3D 0; t->last_event_time =3D 0; t->of =3D of; @@ -1350,6 +1347,8 @@ struct psi_trigger *psi_trigger_create(struct psi_gro= up *group, char *buf, if (privileged) { mutex_lock(&group->rtpoll_trigger_lock); + window_reset(&t->win, sched_clock(), + group->total[PSI_POLL][t->state], 0); if (!rcu_access_pointer(group->rtpoll_task)) { struct task_struct *task; @@ -1375,6 +1374,9 @@ struct psi_trigger *psi_trigger_create(struct psi_gro= up *group, char *buf, } else { mutex_lock(&group->avgs_lock); + window_reset(&t->win, sched_clock(), + group->total[PSI_AVGS][t->state], 0); + list_add(&t->node, &group->avg_triggers); group->avg_nr_triggers[t->state]++; -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}