From nobody Fri Apr 3 04:52:59 2026 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 8801535CBA2 for ; Tue, 17 Feb 2026 13:11:23 +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=1771333884; cv=none; b=J+Hg3aMX7Y6aZjBBrPxhxZH2CU4EUYvWAVFO8+V5peNIgGYYESXNgTv6pV3qBYYY0lqGX3+gWif5O++bRhScmwE8AGFpz6OIOTY32R5qxPZ9CIBhH2F2xQN52G/0p80a4sZWiC4CsF5/ZxqiG+jLxSRnDCgzg3x9kZVqxNToIhA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771333884; c=relaxed/simple; bh=0nRlw430R/aiNR/KjIHNUr/76QXE9wKW6X47zXnArRo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=ZICF0nSlRdQ0WFw+Xm/KNaaxdbxVDhI1TgqdI28Efrh/B6Bo7eLh1oZwwCoLGbf5QRpoRmLojkOs+ULuBe5j0fT3cx4BqFnP9urlwK/wIr+YilgKxkjRW0/s7UvcGjxvuE7D4e1/PXONZTOXczRqekfP5VZEsMerotHsqkAZAvQ= 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=XxRZdQv2; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Q9thqvDG; 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="XxRZdQv2"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Q9thqvDG" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1771333881; h=from:from: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; bh=4gipll7LDiLNEnfusSRxpjOc0YbYsMD1WK+JD3bUTMs=; b=XxRZdQv2ok8T7mNERpRLDonYugghdByMcqyIbAhjxTPL7GoJqnDlHfCY2IZ/3+BiLVx1yN K9D0237zpZJDZh4XXxIaQz9k7NaadfXm8ifAciOO1esq8Jr6lqVlXcIsipjXhlNZVlUY3C C/3UJwZ8aJrSoYMtqeRCs797VufuFH9VyXiie5OI8Sy2jX7ZebdFYw2l4cY707EUo51a0F 1IWZgwgrbEC32vmwxxmop9Z746EVSTT59SGBnpEJdxUS4uvJtUT38ZzRqxQJYLGQZze9oy nSR3d45DL/CGjcl5E1cw7/8WCSiLOSMGa470WCNmeVRi8fjKTY38ylidhhiP6Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1771333881; h=from:from: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; bh=4gipll7LDiLNEnfusSRxpjOc0YbYsMD1WK+JD3bUTMs=; b=Q9thqvDG1keOAltvfNiReqsUTkxH3+2ym8gy3ULgWnPBhI7uQzrupHLKsSFzxERa+MPA/P yM39of0ofW3ZQ/Dw== Date: Tue, 17 Feb 2026 14:11:11 +0100 Subject: [PATCH] stop_machine: Fix the documentation for a NULL cpus argument Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260217-stop_machine-comment-v1-1-a6271c97113b@linutronix.de> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQqAIBBA0avErBNqyKSuEhFmU81CDZUIwrsnL d/i/xciBaYIY/VCoJsje1fQ1hWYU7uDBG/FgA32DbZKxOSvxWpzsiNhvLXkklCDXHHdUKtOQkm vQDs//3aac/4AKoyoU2YAAAA= X-Change-ID: 20260217-stop_machine-comment-795b2bd2a745 To: "Paul E. McKenney" Cc: Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Developer-Signature: v=1; a=ed25519-sha256; t=1771333876; l=2145; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=0nRlw430R/aiNR/KjIHNUr/76QXE9wKW6X47zXnArRo=; b=/qHbtPKdl0SCY8p6B/8kAIhGkqnzdRUn1WnsioMXiefusbec+VD9Piaj7ETaNnVwYtXuOaOmf v37R8qlJd/jCo9JcrcVMyV4vLFVOgoiZ4h2xW0sJnwdE1nvZGENXMgS X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= A recent refactoring of the kernel-docs for stop machine changed the description of the cpus parameter from "NULL =3D any online cpu" to "NULL =3D run on each online CPU". However the callback is only executed on a single CPU, not all of them. The old wording was a bit ambiguous and could have been read both ways. Reword the documentation to be correct again and hopefully also clearer. Fixes: fc6f89dc7078 ("stop_machine: Improve kernel-doc function-header comm= ents") Signed-off-by: Thomas Wei=C3=9Fschuh Reviewed-by: Sebastian Andrzej Siewior --- There doesn't seem to be a formal maintainer for stop_machine. Paul, could you take this through your tree? --- include/linux/stop_machine.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 72820503514c..01011113d226 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -99,7 +99,7 @@ static inline void print_stop_info(const char *log_lvl, s= truct task_struct *task * stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr to pass to @fn() - * @cpus: the cpus to run @fn() on (NULL =3D run on each online CPU) + * @cpus: the cpus to run @fn() on (NULL =3D one unspecified online CPU) * * Description: This causes a thread to be scheduled on every CPU, which * will run with interrupts disabled. Each CPU specified by @cpus will @@ -133,7 +133,7 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const st= ruct cpumask *cpus); * stop_machine_cpuslocked: freeze the machine on all CPUs and run this fu= nction * @fn: the function to run * @data: the data ptr to pass to @fn() - * @cpus: the cpus to run @fn() on (NULL =3D run on each online CPU) + * @cpus: the cpus to run @fn() on (NULL =3D one unspecified online CPU) * * Same as above. Avoids nested calls to cpus_read_lock(). * --- base-commit: 9702969978695d9a699a1f34771580cdbb153b33 change-id: 20260217-stop_machine-comment-795b2bd2a745 Best regards, --=20 Thomas Wei=C3=9Fschuh