From patchwork Thu Mar 13 15:46:36 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Granados X-Patchwork-Id: 14015336 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4EA58139566; Thu, 13 Mar 2025 15:47:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741880866; cv=none; b=hyL+kPNopmN9aaO2blSexsrfLCeVrgIw/gI2jD/I/KmEWCyICHkBhNBfD5I3QjknVqFGrJLa6VEMeHlQzZCAmb8zUnk4mMG0u5yF2CA0j2Iy9JykTMYXUItSA0gd9J8awzhFSJkdCOrSElG6SdJoJRTGGY2o/9z1VSe8nTrhkQs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741880866; c=relaxed/simple; bh=onqUyIR18v4Kxp915+i4qq8AG9pw2nIIaV6s1W5Ie2I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=VWRa+1ssXNudvacYgoeA2af49oB6KZc5tnT8OgtJyOoG43tIVuUfs82i+RWRBFMiK8RfjmtS9g+qYix4k+fgU3l2M4KP0ggV1Ksl3KCW7Lv6aUntCBFRaRMuTEd81tKTOyhZYxtmW3litHiijAPCJ543sy3mrFxyLeC+mmObJWs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lQxtePXT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lQxtePXT" Received: by smtp.kernel.org (Postfix) with ESMTPS id 95D30C4CEE9; Thu, 13 Mar 2025 15:47:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741880865; bh=onqUyIR18v4Kxp915+i4qq8AG9pw2nIIaV6s1W5Ie2I=; h=From:Date:Subject:To:Cc:From; b=lQxtePXTfEadnLpjvvPl7XxUoSl9Qo3TsM1GMMsjMkYD50VHaFJ0x8lGqB4y3fQ00 x9FHqU1ohbEmGbLtnbhs1Y7Rq4PRsJL+k9V0I8UPfTZP/a9hNQoYtc/VJcCx0EaMva j7R9GW/sVG5zPgAqx620jsEn8wUTAEmPNmqqpCl4rSpgERRah10xeojg07FPwUuatZ hhrM60EVguG0AfXtKxeOZ0ioc4MxCRDlpkCPuLFlInTbmY0q4GtZ9wHnf2MCp/PDZx HltGKukvVznQMeStTahVpwSn40QJHJwlJP/iRZ+jatQ4gcyNpSx1DstRVTeOIpSECt 4wUs5mD0vgMmA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BD1EC35FF3; Thu, 13 Mar 2025 15:47:45 +0000 (UTC) From: Joel Granados Date: Thu, 13 Mar 2025 16:46:36 +0100 Subject: [PATCH] drop_caches: Allow re-enabling message after disabling Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250313-jag-drop_caches_msg-v1-1-c2e4e7874b72@kernel.org> X-B4-Tracking: v=1; b=H4sIANv90mcC/x3MTQqAIBBA4avErBM0a9NVIsKf0SZIxYEIorsnL b/Few8wVkKGuXug4kVMOTWovgO3mxRRkG+GQQ6T1EqLw0Thay6bM25H3k6Owo3BBvR2UkFDK0v FQPd/Xdb3/QD22YgqZQAAAA== X-Change-ID: 20250313-jag-drop_caches_msg-c4fbfedb51f3 To: Jonathan Corbet , Alexander Viro , Christian Brauner , Jan Kara Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Ruiwu Chen , Luis Chamberlain , Joel Granados X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=1756; i=joel.granados@kernel.org; h=from:subject:message-id; bh=onqUyIR18v4Kxp915+i4qq8AG9pw2nIIaV6s1W5Ie2I=; b=owJ4nAHtARL+kA0DAAoBupfNUreWQU8ByyZiAGfS/f6CEC4g2XnGlGRlSme4x3oOFMFovBpF7 JcxYrJVTJTsb4kBswQAAQoAHRYhBK5HCVcl5jElzssnkLqXzVK3lkFPBQJn0v3+AAoJELqXzVK3 lkFPPNYL/jHTPUPVYZaSe0Tz1azPRYnf0WszSAKm+jNqgbZXptpqSIgTNuiRiXalABLa94PT/vf kNo26IgXSmsz7t/qRDUCSg6URaTItyfUMQ5kE12xtzqu4t6PBNRa0QfTcGG+ZkcQtD9k6iSx48u wWzjVc/l72eww/CtfGAvwGATdzt2jUxofWkUyPsXA9jYIs5staKiBzDPPgGhVWV3uUdXP+5xXws UxlT61ooON9PW0HVJds9DzHZz1/tO88Qgy5gs/kbheAPlL3sIIYxxyt/LwPyy9A8GrTZl/uSJv6 OXIlkJ87Yt1cZBNYONFDiLdu+W8YJPmQpiGRZ+hGfAmJ/ExvRYCuZyz6CjtY+cc55YWjCCzRzdX IfaG1MM4FeDnkRVEjCRt5idGfM8rKxHfebqk4Z+HvAoqyPT8sBObxGl/r4Hu6ZvW4BLBUZfe6iy Y/BCsgAwQeMx4Df2x3fvD9rZpAYpFK5EB1VMx9/9znIOKAScp9HCqENAKc46/Sn6Jm8qAlyt0a7 N0= X-Developer-Key: i=joel.granados@kernel.org; a=openpgp; fpr=F1F8E46D30F0F6C4A45FF4465895FAAC338C6E77 X-Endpoint-Received: by B4 Relay for joel.granados@kernel.org/default with auth_id=239 After writing "4" to /proc/sys/vm/drop_caches there was no way to re-enable the drop_caches kernel message. By removing the "or" logic for the stfu variable in drop_cache_sysctl_handler, it is now possible to toggle the message on and off by setting the 4th bit in /proc/sys/vm/drop_caches. Signed-off-by: Joel Granados --- Documentation/admin-guide/sysctl/vm.rst | 2 +- fs/drop_caches.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 change-id: 20250313-jag-drop_caches_msg-c4fbfedb51f3 Best regards, diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index f48eaa98d22d2b575f6e913f437b0d548daac3e6..75a032f8cbfb4e05f04610cca219d154bd852789 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -266,7 +266,7 @@ used:: cat (1234): drop_caches: 3 These are informational only. They do not mean that anything is wrong -with your system. To disable them, echo 4 (bit 2) into drop_caches. +with your system. To toggle them, echo 4 (bit 2) into drop_caches. enable_soft_offline =================== diff --git a/fs/drop_caches.c b/fs/drop_caches.c index d45ef541d848a73cbd19205e0111c2cab3b73617..501b9f690445e245f88cbb31a5123b2752e2e7ce 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -73,7 +73,7 @@ int drop_caches_sysctl_handler(const struct ctl_table *table, int write, current->comm, task_pid_nr(current), sysctl_drop_caches); } - stfu |= sysctl_drop_caches & 4; + stfu = sysctl_drop_caches & 4; } return 0; }