From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792785660; b=qZCAUrRg+vgHUh0dBlLFSyC5n+tlSCcxTOXZCvAFkgWCsuPYtAW1bjKQ7D3rpwLaPgBM jvuPPH0ITxiTOryEnnBrfN+mEf2REHABCkXTZ59OhHyuw+unVUhnSN8L1K9KbvDH8Hp+T XyNdpwYC+kiDBFajvvRz0EkT8AB6rw3Ytadaghf+6lNcGH6tN4nF1BfvY56fmhzhUyWDq kjCSsaK+mv0P6duzecWcrMygsw2jLcn4dA0DC4bZNn90Ima68w6tiCrYT0ktwAP7/7lJB qI+Jrh9bYZSe2YUJmNHJxDHIZsepIJVtMjRqjOa+q3gyZGko7K5kSb1GQG1IEC8O5tw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792785660; h=DMARC-Filter:DKIM-Signature:Received:X-MC-Unique: X-Mimecast-MFC-AGG-ID:Received:Received:From:To:Cc:Subject:Date: Message-ID:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Scanned-By; bh=W2zdrfASIgne8nhIAu/3iGRmmi2su/VRFMJWYm0YZkA=; b=N8XOK1DH/+QZApmAuB+AN6uQ1IexgzQS55HuYpzLEIwUkjrlOD6OS9WxzinJ0lunuTmL Xe8330sT0lKgIxtnoKoa+KnAAZtdi/PkwhDpo2B+1ZHVhO07oUQSQ9QzgH2sv1FSmKf1i AQdYxW7OekTVU1k58I+0B/bZF5tyb20p83w9GMDFldOqZL2+Yibd4qd1IJDdFyQmvmiJO kTpZazHVhpfDSuhAnCRseTRL4FOQot1eVNTyC6S45M8AX1rTYYMR1gZCpnSAh8MvI/rps uOgz/9LtoJ8oy3YQKwaraEzysgUhIRU4SG7uGikieSZ5H4vrXGz79/7zl7V3TRGcgcA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=OtRsUU21; arc=none smtp.remote-ip=170.10.133.124 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CDC92606A331 for ; Fri, 23 Oct 2026 20:00:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org CDC92606A331 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=OtRsUU21 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1792785659; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=W2zdrfASIgne8nhIAu/3iGRmmi2su/VRFMJWYm0YZkA=; b=OtRsUU21XHj7EpJQ4qtmZZ3hRYR8cWYNJ6MmafCrR9uy8e3ApgqBmKf2g6LaEUqrPF6xag GIeAEmFxOQ4iWZUG5Dv3RB6Q4ZxvZbQPEui7jkFSxumSxQrONMFq5pVCRBQyjPlG8skV3u QINrfMTVUHwUgs42RTSRpENoMhLcylE= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-610-u0XX_IM4OGSrcEcGpijfmQ-1; Fri, 23 Oct 2026 16:00:54 -0400 X-MC-Unique: u0XX_IM4OGSrcEcGpijfmQ-1 X-Mimecast-MFC-AGG-ID: u0XX_IM4OGSrcEcGpijfmQ_1792785653 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 161CD1801360; Fri, 23 Oct 2026 20:00:53 +0000 (UTC) Received: from llong-thinkpadp16vgen1.redhat.corp (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 770CC1956089; Fri, 23 Oct 2026 20:00:51 +0000 (UTC) From: Waiman Long To: Ridong Chen , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Shuah Khan Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Guopeng Zhang , Waiman Long Subject: [PATCH-next v2 03/10] cgroup/cpuset: Fix incorrect effective_cpus bug in update_cpumasks_hier() Date: Fri, 23 Oct 2026 16:00:29 -0400 Message-ID: <20261023200036.60560-4-longman@redhat.com> In-Reply-To: <20261023200036.60560-1-longman@redhat.com> References: <20261023200036.60560-1-longman@redhat.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 With the introduction of cpuset.cpus.exclusive, the computation of effective_cpus differs depending on if a cpuset is a valid partition root or not. In update_cpumasks_hier(), effective_cpus is computed early to check if the current subtree can be skipped. Later on update_parent_effective_cpumask() may be called which can change the partition state from valid to invalid or vice versa. If the partition state changes, the previously computed effective_cpus may no longer be valid. Fix that by recomputing effective_cpus again when that happens. Also add a new test case into test_cpuset_prs.sh to verify this change. Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2") Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 10 ++++++++-- tools/testing/selftests/cgroup/test_cpuset_prs.sh | 3 +++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 06b8a67cbd3d..69fc02cd7469 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2315,10 +2315,16 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp, if (update_parent) { update_parent_effective_cpumask(cp, partcmd_update, NULL, tmp); /* - * The cpuset partition_root_state may become - * invalid. Capture it. + * Capture current partition_root_state as it may have + * changed. Recompute effective cpumask if changed. */ new_prs = cp->partition_root_state; + if (new_prs != old_prs) { + if (new_prs > 0) + compute_partition_effective_cpumask(cp, tmp->new_cpus); + else + compute_effective_cpumask(tmp->new_cpus, cp, parent); + } } spin_lock_irq(&callback_lock); diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index 8bdda955b4a7..f4eb984752a0 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -364,6 +364,9 @@ TEST_MATRIX=( " C1-4:X2-4 C2-4:X3-4:P1 C3-4:X4:P2 \ . . X5 . . 0 A1:1-4|A2:2-4|A3:3-4 \ A1:P0|A2:P-1|A3:P-2 ." + " C1-5:X3-5:P2 C3-5:X4-5:P2 C4-5:X5:P2 \ + . X1-4 . . . 0 A1:1-3|A2:4|A3:4 \ + A1:P2|A2:P2|A3:P-2 1-4" " C1-4:X2-4 C1-4:X3-4:P1 C3-4:X4:P2 \ . . . X1 . 0 A1:1-2|A2:3-4|A3:3-4 \ A1:P0|A2:P1|A3:P-2 ." -- 2.56.0