From nobody Tue Dec 2 01:06:30 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 305E4222566 for ; Tue, 25 Nov 2025 03:27:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764041243; cv=none; b=psEpq85lyYPDMNV5XhQc2WBv9gTH0G5okRKceeBX06IvB1iVJDZrn2yK3oplutq5UXoV20jOiUFtqYIw0NdVU1vemJYyTN21AgLsmlbRY3zlEvW0ANtewJZaLSWY6H6jJcafWkZXSJlXAUS7BozRCN4XcGCnY2n4yMSjXrB6Mcs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764041243; c=relaxed/simple; bh=/hsR3zuYvVWfg88WpWLt/kRZTVdjYH6OHFTkCj2tUD4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lx3BxE6Gl4GT3pRYvkEkWm/6QALRfigec7MGCldYQth1uz+9DJVz0TQ0Wg0HOAwNysScB0mIybaUntEYsy0r4vVOTCFS2T06IyhzMvgYagYkj8tS6EtTnJTUQWzcdzJPPCNiR+IPDi7TLigzYZ4Lp0X0RgCoUMPGZe/IHwOVveY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=W7QvslgY; arc=none smtp.client-ip=170.10.129.124 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) header.d=redhat.com header.i=@redhat.com header.b="W7QvslgY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764041241; 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=F9n4PdkywfT2V89/jL5nJ7OWHOEyn12fJUBABHG/tyc=; b=W7QvslgYRFJ8nxKDQKc3LmNJKfbIfGwj/75ecICuoQqeJ9rjVI8EtojXTJ61eFeZeFRdYy uEnopIL79iRMfdI9Fn+Fr48RdqwzeCBXcRxMFRCEKCSWbFqUfkwT/k7bVicy3QYBxSW93E gJMo8HXz3WNfeWjw25t5Ynfy8JFbxEM= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-661-A_3pCBxTO0GnAI7cWQYUPQ-1; Mon, 24 Nov 2025 22:27:17 -0500 X-MC-Unique: A_3pCBxTO0GnAI7cWQYUPQ-1 X-Mimecast-MFC-AGG-ID: A_3pCBxTO0GnAI7cWQYUPQ_1764041236 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A16FB19560B7; Tue, 25 Nov 2025 03:27:15 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.72.112.53]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 12A183003761; Tue, 25 Nov 2025 03:27:07 +0000 (UTC) From: Pingfan Liu To: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Pingfan Liu , Tejun Heo , Waiman Long , Chen Ridong , Peter Zijlstra , Juri Lelli , Pierre Gondois , Ingo Molnar , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider Subject: [PATCHv2 1/2] sched/deadline: Remove unnecessary comment in dl_add_task_root_domain() Date: Tue, 25 Nov 2025 11:26:29 +0800 Message-ID: <20251125032630.8746-2-piliu@redhat.com> In-Reply-To: <20251125032630.8746-1-piliu@redhat.com> References: <20251119095525.12019-3-piliu@redhat.com> <20251125032630.8746-1-piliu@redhat.com> 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 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Content-Type: text/plain; charset="utf-8" The comments above dl_get_task_effective_cpus() and dl_add_task_root_domain() already explain how to fetch a valid root domain and protect against races. There's no need to repeat this inside dl_add_task_root_domain(). Remove the redundant comment to keep the code clean. No functional change. Signed-off-by: Pingfan Liu Cc: Tejun Heo Cc: Waiman Long Cc: Chen Ridong Cc: Peter Zijlstra Cc: Juri Lelli Cc: Pierre Gondois Cc: Ingo Molnar Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Mel Gorman Cc: Valentin Schneider To: cgroups@vger.kernel.org To: linux-kernel@vger.kernel.org --- kernel/sched/deadline.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 194a341e85864..0b6646259bcd7 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2952,20 +2952,11 @@ void dl_add_task_root_domain(struct task_struct *p) return; } =20 - /* - * Get an active rq, whose rq->rd traces the correct root - * domain. - * Ideally this would be under cpuset reader lock until rq->rd is - * fetched. However, sleepable locks cannot nest inside pi_lock, so we - * rely on the caller of dl_add_task_root_domain() holds 'cpuset_mutex' - * to guarantee the CPU stays in the cpuset. - */ dl_get_task_effective_cpus(p, msk); cpu =3D cpumask_first_and(cpu_active_mask, msk); BUG_ON(cpu >=3D nr_cpu_ids); rq =3D cpu_rq(cpu); dl_b =3D &rq->rd->dl_bw; - /* End of fetching rd */ =20 raw_spin_lock(&dl_b->lock); __dl_add(dl_b, p->dl.dl_bw, cpumask_weight(rq->rd->span)); --=20 2.49.0