From nobody Sun Oct 5 07:19:06 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 6659B29BDBA; Mon, 11 Aug 2025 17:25:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754933115; cv=none; b=utyvEdksbXIuGx2LZfeqU0nndNuEcBaWvBUrDyK769IpQuLejKj9X/OC2cwc4IEmTPJjhP2sJiCdbynW8/WOahadWl/9MflWoPZxrVD/OiwhT3KIOXtSTOJyjUqaDrOx4ssYtrzeVkugzsmFUC4cZRHQamW2B4GNsWmPPsEE2zY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754933115; c=relaxed/simple; bh=Mr51pGZCpLW0ChniTNNlm3LmAhUQ+EpAcSf5C6gpb3Q=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=HAcG0XAFtDFjm+HShIZX0vSDge2xesyPtcdjn6Ebg/8Arj3AFimYihdFXdi6WAa9L8YfQ0t9Rqd1+Xv7sRI5y2+kVFoTArDlIwXnQtwFDqYKwNAXDUrSyXWcNWrVGdIei0rRZk5pKe3IZ6iWgSmAJnWWvSfeJyva/1Zss1xJ+a0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=DpM8TDKg; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Z/vB4VX4; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="DpM8TDKg"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Z/vB4VX4" Date: Wed, 06 Aug 2025 20:59:30 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1754933111; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tqsES6jVDc9uIRKGOc6ivp3AYGfhaE85QUu5RbHj7dA=; b=DpM8TDKgmG/STbBNNrDm8cdgsizhKKXVzqODZHWZP1mC3pCviemhsrk5pxtYHW21OLMGP9 DVclq9eUsdcdKPGMXIa0sADYT3AySCuFPLyswKXjL11CXlXzJQEvwZjBCfTvr3nFS90zzs gSqvnhgx9YpO2oiqHsTWxpBO8i/+BjJIq4UL3kuKImyyLLr2fZ6KdCdfsgmSuiv3S38UoY SYY2bx97KvRIAe3pbGUQes3QM2VPhjWUxWNg3PqliIyYoRHPc6mvFYkkTLrYzRbTdgUzN7 OZofpAftcctSfdgziidjofhuNU3HM5T6GxQ/KrlSAEskciQl0gVlAo3He7jWkQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1754933111; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tqsES6jVDc9uIRKGOc6ivp3AYGfhaE85QUu5RbHj7dA=; b=Z/vB4VX4G4fLicIt/LytN3sStW9xICqRDVYlgJYUvDNs8St6Edt20P3R8e5WkYBlGjBBIx wj7mZAPkfU1GhFDw== From: "tip-bot2 for Waiman Long" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: smp/urgent] cpu: Remove obsolete comment from takedown_cpu() Cc: Waiman Long , Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250729191232.664931-1-longman@redhat.com> References: <20250729191232.664931-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175451397101.1420.5655871917271400595.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the smp/urgent branch of tip: Commit-ID: da274853fe7dbc7124e2dd84dad802be52a09321 Gitweb: https://git.kernel.org/tip/da274853fe7dbc7124e2dd84dad802be5= 2a09321 Author: Waiman Long AuthorDate: Tue, 29 Jul 2025 15:12:32 -04:00 Committer: Thomas Gleixner CommitterDate: Wed, 06 Aug 2025 22:48:12 +02:00 cpu: Remove obsolete comment from takedown_cpu() takedown_cpu() has a comment about "all preempt/rcu users must observe !cpu_active()" which is kind of meaningless in this function. This comment was originally introduced by commit 6acce3ef8452 ("sched: Remove get_online_cpus() usage") when _cpu_down() was setting cpu_active_mask and synchronize_rcu()/synchronize_sched() were added after that. Later commit 40190a78f85f ("sched/hotplug: Convert cpu_[in]active notifiers to state machine") added a new CPUHP_AP_ACTIVE hotplug state to set/clear cpu_active_mask. The following commit b2454caa8977 ("sched/hotplug: Move sync_rcu to be with set_cpu_active(false)") move the synchronize_*() calls to sched_cpu_deactivate() associated with the new hotplug state, but left the comment behind. Remove this comment as it is no longer relevant in takedown_cpu(). Signed-off-by: Waiman Long Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250729191232.664931-1-longman@redhat.com --- kernel/cpu.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index faf0f23..db9f6c5 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1309,9 +1309,6 @@ static int takedown_cpu(unsigned int cpu) */ irq_lock_sparse(); =20 - /* - * So now all preempt/rcu users must observe !cpu_active(). - */ err =3D stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); if (err) { /* CPU refused to die */