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=1792639057; b=3/WvyRn+Kxj0PUYa0W0P/appfRFoe36/HAql4Q2qJnvruwphGgiAi/5Ql4QsAFeKefaT BlcfURkYN+K0t294IpYOnA0WN+phqJ4g215cKpc5pngtzXQpKSvrkDjjxF3jN9ZMZhfDP TvJz9YN/Cq9trT0yADCHa0IgJYPkBa8+jhFRtUO+BVLt/hPdQdJwJdE2oB4uWQkrCQjOy T/tbU/ZryqnxbMX7Zzqmkhg5UKBpHcENZHX2itFEjdaD7arY3FU9f/s4196F7A63ufSOX 4j0Umq4Birhn84Om5/KAwIQxM+784KSoO2GAlvibFUVIQxSkf+jvZceVmcUHqwbRDdw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792639057; 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=ng2Z4i0l6+f8aePkaaylUNGsht+qS83D5TBM5+FHNM8=; b=MfNIBlKlcNnWYmtbiXEXebvAIvBcWB0qiTixuc9+IQ0sUnyP4BAikLX4+Gr7SB9K9oaC a0clnXAKYUu4P6h6TbpBLkYzkmq1aEjZV9yeqL4VBfme9AZpbzkJlmbHWp8reJMLgGe9e Ua/juj3ZnJg1pUehVNlk26oJy/fTYBzjRh+/i7jJGoqIp4PhGM1FYCyW2NB4TmC1RDhkJ yNJl2aCs9wtHulnocYwopmKZ+pTTtOGoYoSb+4kvoEEN/qoA9eOoCmH3rh8sdLhga59fl rQ0qvABCQzMCwwnYEGjnwcEYnMzh7hhFyCL7xvtUP/Yo1RINEhfUMVPD3pFI6Lbi7fw== 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=FQzkRbnd; 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 2CC6060A261B for ; Thu, 22 Oct 2026 03:17:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 2CC6060A261B 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=FQzkRbnd DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1792639056; 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=ng2Z4i0l6+f8aePkaaylUNGsht+qS83D5TBM5+FHNM8=; b=FQzkRbndmafez0Ji8lVMrpBTKGDZHcVZ4nUw99u2Jdt6kgcpSdjGVwWQYreAgfqrZRicta SEGvL9XQWBGnfG6eoJdSjYOIkSEsJxPmEr4IfgLLZuaeX8uTBJyNrCeAVNxSUgYykdbONJ F+Yoqui2bnfGa/7SYzYFOAHW2Qyd4+k= 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-68-AL9Gff16OyykHnf4Ff_WPA-1; Wed, 21 Oct 2026 23:17:30 -0400 X-MC-Unique: AL9Gff16OyykHnf4Ff_WPA-1 X-Mimecast-MFC-AGG-ID: AL9Gff16OyykHnf4Ff_WPA_1792639049 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 57EB61800657; Thu, 22 Oct 2026 03:17:29 +0000 (UTC) Received: from llong-thinkpadp16vgen1.rmtusnh.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 95A9418005B7; Thu, 22 Oct 2026 03:17:27 +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 3/6] cgroup/cpuset: Fix incorrect effective_cpus bug in update_cpumasks_hier() Date: Wed, 21 Oct 2026 23:16:40 -0400 Message-ID: <20261022031643.1351877-4-longman@redhat.com> In-Reply-To: <20261022031643.1351877-1-longman@redhat.com> References: <20261022031643.1351877-1-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 3.4.1 on 10.30.177.111 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 db6e4663f4be..7b9062326f35 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2316,10 +2316,16 @@ 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 47791591002f..8595b6b4b7bf 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 ." -- 2.55.0