From nobody Sat Jun 20 00:54:36 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99CABC433F5 for ; Fri, 25 Mar 2022 16:44:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376818AbiCYQqT (ORCPT ); Fri, 25 Mar 2022 12:46:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356626AbiCYQqR (ORCPT ); Fri, 25 Mar 2022 12:46:17 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7BF9E3B038 for ; Fri, 25 Mar 2022 09:44:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648226682; 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; bh=645Y/OtWrXfu94ghKzgX/CYbJeHjL6KM1tOHVX36Llw=; b=gqi31fETvZTVfob8BwFHWktM7Dasp8+2Zwwmp6gz5uIGcPgUNJIc1QcXiP47iHABycu5pT 3Eer5KeCFn4nIBZMpZ7ejaUbl9Ot307TqlwSVY3wh2N5904Om2fwMoCsUcjLQrLZZxByYD N3XAnZ8kLTXtmzyjy0gcyD3jJpBRyhU= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-330-HScAVXZTN_-2Y2yNBxpRZg-1; Fri, 25 Mar 2022 12:44:41 -0400 X-MC-Unique: HScAVXZTN_-2Y2yNBxpRZg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 34372280D417; Fri, 25 Mar 2022 16:44:40 +0000 (UTC) Received: from jsavitz-csb.redhat.com (unknown [10.22.33.7]) by smtp.corp.redhat.com (Postfix) with ESMTP id 33E5640CF8EC; Fri, 25 Mar 2022 16:44:39 +0000 (UTC) From: Joel Savitz To: linux-kernel@vger.kernel.org Cc: Joel Savitz , Jonathan Corbet , Andrew Morton , Vlastimil Babka , Mel Gorman , Dave Hansen , Suren Baghdasaryan , Mike Rapoport , "zhangyi (F)" , Charan Teja Reddy , linux-doc@vger.kernel.org Subject: [PATCH] Documentation/sysctl: document page_lock_unfairness Date: Fri, 25 Mar 2022 12:44:37 -0400 Message-Id: <20220325164437.120246-1-jsavitz@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" commit 5ef64cc8987a ("mm: allow a controlled amount of unfairness in the pa= ge lock") introduced a new systctl but no accompanying documentation. Add a simple entry to the documentation. Signed-off-by: Joel Savitz --- Documentation/admin-guide/sysctl/vm.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-= guide/sysctl/vm.rst index f4804ce37c58..747e325ebcd0 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -62,6 +62,7 @@ Currently, these files are in /proc/sys/vm: - overcommit_memory - overcommit_ratio - page-cluster +- page_lock_unfairness - panic_on_oom - percpu_pagelist_high_fraction - stat_interval @@ -754,6 +755,14 @@ extra faults and I/O delays for following faults if th= ey would have been part of that consecutive pages readahead would have brought in. =20 =20 +page_lock_unfairness +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D + +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 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 --=20 2.27.0