From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.161 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794287021; b=0XgIRjFIlSPtyvpQjKsme5js/SjX6CdGY+9kZdAqlFXl/sfnNZajtQrCdeHdlND0hy6I Cjlj3QapF8GL8eLcw0lcIv3pyNfXQ6+Lusa/G4MD1+pZtmhViMdpEAIn7GfXTsdzG/czT 8iiwo5hdbgmLdH5XC8VNSOAU7L51y2+mVLMCKz/OJb+wzxiHez6E/4hmosGy4E90xcj21 dCO5BeRk/zOMHQ2A9DXfvpt754eaG7hw9bkPD0+g3AYQF80qZEonwGEq2lYY2YKeNcijr Ui5JLoH+Tf15WUVcg8/KlYC9PmiMlsF+PzzEdFidO5nvw3N2NGSOxJMzifvH9pxEcgw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794287021; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:MIME-Version:Content-Transfer-Encoding; bh=W1sxioC7CMROvx/r1UAJHDcZA5UE9rSvFPDNj6JhOK4=; b=yBsnmNbbmrXIKn5OOeVqMG2SvciXQzFUr82TWoyz9epb2AuBOa+g95OuoSYgolNdaPvb c68dcIniGe69cXky4++kpf4FpO1AQ3+dWEdeTwf+6QCbkd39U4kT3UXqTjlZrMlS+I6cK +Ml9KueiOLSBP+BzLlHH0f3gZBxC/d2SngbpvLeu49W/DFN8q4P8Qs7LMxG+o8P3bYI9Z +c37rtn47xuiHXIFXH5dM0rK6cnh1ZZ/s7p0FYXCgdDEZ1euKOmeFExTH8Du6Q047ql+M y28gIL1U8i96VWdRPr5NfQgQrsLuS7o6ujqK93l1pkUIDpwcVQTFGTmRWQGsTROs49A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=dWImxHsR; arc=none smtp.remote-ip=95.215.58.161 Received: from mta1.migadu.com (out-161.mta1.migadu.com [95.215.58.161]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D11A2606B090 for ; Tue, 10 Nov 2026 05:03:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org D11A2606B090 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=dWImxHsR X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=Qr6efF4jJpI/9qmyxgdFUkjEvcMPZqgHpk0hHki1Z4s=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794287018; v=1; x=1794891818; b=dWImxHsRkvJSoxPLXq54ffkl6WuZS5XUWVPOZ9/+1MKChgY0A/oSEyuWT3WLSoZBd56cLDxQ f5kCmEqx47WrbHA+RoiWrhSdgLJWfyP7+CmHo4RK/msQnBQlx2OMHP6bCIEiS/8+LauFLtQCOog ZrZWCS4z1SvDM5oCSoX657i8= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 2b2d84358f04e1ee; Tue, 10 Nov 2026 05:03:37 +0000 X-Mizu-Trace-ID: 2b2d84358f04e1ee X-Migadu-Flow: FLOW_OUT From: Guopeng Zhang To: Waiman Long , Tejun Heo Cc: Ridong Chen , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Shuah Khan , Mathieu Desnoyers , Guopeng Zhang , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Guopeng Zhang Subject: [PATCH v3 0/3] cgroup/cpuset: Keep the top scheduling domain populated Date: Tue, 10 Nov 2026 13:03:21 +0800 Message-ID: <20261110050324.173461-1-guopeng.zhang@linux.dev> X-Mailer: git-send-email 2.43.0 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 From: Guopeng Zhang Boot-isolated CPUs stay in top_cpuset.effective_cpus, but are excluded from its scheduling domain. Allocating all boot domain housekeeping CPUs to partitions can therefore leave the top scheduling domain empty even though effective_cpus is nonempty, leading to warnings and an OOPS in build_perf_domains(). CPU hotplug can reach the same state. The patches are ordered as follows: 1. Check local and remote partition creation and CPU mask updates. 2. Allow top-level partition CPU replacements that return CPUs to the parent in the same update. 3. Handle CPU hotplug and preserve partitions that cannot return an active boot domain housekeeping CPU. Changes since v2: Keep patch 1's kernel changes unchanged. Update its selftests following Longman's and Sashiko's comments and cover recovery with a single top-level HK CPU. Add patch 2 to fix the CPU replacement rejection reported by Sashiko, with its own regression test. Update the hotplug fix, now patch 3, to avoid invalidating unrelated partitions, including partitions whose boot housekeeping CPUs are all offline. Drop v2's isolated CPU cleanup patch in favor of Ridong's fix: https://lore.kernel.org/all/20261107120100.3587595-4-ridong.chen@linux.dev/ v2: https://lore.kernel.org/all/20261105130344.664336-1-guopeng.zhang@linux.dev/ Changes since v1: Rework the fix following Ridong's suggestion and add test cases. Add patch 2 for CPU hotplug and patch 3 for isolated CPU cleanup when the parent partition becomes invalid. v1: https://lore.kernel.org/all/20261104071600.474587-1-guopeng.zhang@linux.dev/ Guopeng Zhang (3): cgroup/cpuset: Reject updates that empty the top sched domain cgroup/cpuset: Allow top-level partition CPU replacement cgroup/cpuset: Keep the top sched domain non-empty on CPU hotplug kernel/cgroup/cpuset.c | 75 +++++++++++++++++-- .../selftests/cgroup/test_cpuset_prs.sh | 68 +++++++++++++++++ 2 files changed, 137 insertions(+), 6 deletions(-) -- 2.43.0