From mboxrd@z Thu Jan 1 00:00:00 1970 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 ECFF5611A for ; Mon, 28 Aug 2023 10:42:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 446B7C433C8; Mon, 28 Aug 2023 10:42:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219320; bh=jQTYoidahfGPJyeVDPwfPYqRniXpTNwNduwv3rRNoOo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N3Bb6C3YPDDu0HDhgSG4+8zpfCGNG7fHRwKeRJHv0D6+dNgZIK1BoW9opPBD/bQSt 02bKdBBAZf/57hUmu1CrrszOIfw7IHt/CekV3PYrlSTWNy3RVMEep3W/4EF8IQ2pf5 sjit183MzaFG5IzZtA9wZqGPiveiL5CNoSVbb75Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Joel Savitz , Jonathan Corbet , Vlastimil Babka , Mel Gorman , Dave Hansen , Suren Baghdasaryan , Mike Rapoport , "zhangyi (F)" , Charan Teja Reddy , Linus Torvalds , Andrew Morton Subject: [PATCH 5.4 152/158] Documentation/sysctl: document page_lock_unfairness Date: Mon, 28 Aug 2023 12:14:09 +0200 Message-ID: <20230828101202.828603936@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101157.322319621@linuxfoundation.org> References: <20230828101157.322319621@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joel Savitz commit 8d98e42fb20c25e8efdab4cc1ac46d52ba964aca upstream. commit 5ef64cc8987a ("mm: allow a controlled amount of unfairness in the page lock") introduced a new systctl but no accompanying documentation. Add a simple entry to the documentation. Link: https://lkml.kernel.org/r/20220325164437.120246-1-jsavitz@redhat.com Signed-off-by: Joel Savitz Cc: Jonathan Corbet Cc: Vlastimil Babka Cc: Mel Gorman Cc: Dave Hansen Cc: Suren Baghdasaryan Cc: Mike Rapoport Cc: "zhangyi (F)" Cc: Charan Teja Reddy Cc: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- Documentation/admin-guide/sysctl/vm.rst | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -61,6 +61,7 @@ Currently, these files are in /proc/sys/ - overcommit_memory - overcommit_ratio - page-cluster +- page_lock_unfairness - panic_on_oom - percpu_pagelist_fraction - stat_interval @@ -741,6 +742,14 @@ extra faults and I/O delays for followin that consecutive pages readahead would have brought in. +page_lock_unfairness +==================== + +This value determines the number of times that the page lock can be +stolen from under a waiter. After the lock is stolen the number of times +specified in this file (default is 5), the "fair lock handoff" semantics +will apply, and the waiter will only be awakened if the lock can be taken. + panic_on_oom ============