From patchwork Sat Nov 19 00:51:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13049436 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAE38C4332F for ; Sat, 19 Nov 2022 00:52:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 692B26B007D; Fri, 18 Nov 2022 19:52:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5CEAF6B007B; Fri, 18 Nov 2022 19:52:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4BD5C6B0078; Fri, 18 Nov 2022 19:52:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 39C206B0074 for ; Fri, 18 Nov 2022 19:52:36 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 0270916088D for ; Sat, 19 Nov 2022 00:52:36 +0000 (UTC) X-FDA: 80148366312.25.E690398 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf09.hostedemail.com (Postfix) with ESMTP id 9BF88140008 for ; Sat, 19 Nov 2022 00:52:35 +0000 (UTC) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 550E119380CC; Fri, 18 Nov 2022 16:52:18 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com, linux-block@vger.kernel.org, linux-mm@kvack.org Cc: shr@devkernel.io, axboe@kernel.dk, clm@meta.com, akpm@linux-foundation.org Subject: [RFC PATCH v4 03/20] mm: document /sys/class/bdi//strict_limit knob Date: Fri, 18 Nov 2022 16:51:58 -0800 Message-Id: <20221119005215.3052436-4-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221119005215.3052436-1-shr@devkernel.io> References: <20221119005215.3052436-1-shr@devkernel.io> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1668819155; a=rsa-sha256; cv=none; b=GmI/vw0RcBMX8BFQ8EC1kT+rEb/ocHWlFLKcKs7VMlh7K3LowiJesnj2gv8nu/yZ1HLly9 cuPeubXUjLDPUrLlOxvMfAnWNBXNHRJt+/Chmkr+lKd0TmS5cYGVNBszeA7v235z82MqL6 f/ZeZbIG9zLFwDARlA/IsKIdCAqss+M= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf09.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668819155; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2U+im8+B4wNoFjJqOFLX/rTYATi3Lg6oskSy2dhLr2A=; b=jusS/QDOUSbELS/8Kqlk8L+62hAnMBWfWsNXVatu2kOY8OnIVAezlIjVPxgvOIQFTUgJFm x7Xdm1OqmksKPDnlWhGqX8uzhp3j5MpUdN8ywjJShzQr/me7Yh+4WhDUi3aMpGb+uZbMTQ zww3YDxYtpdAvN4sAzO88WPUIx/cZiE= X-Stat-Signature: 9761ued9n98tju3qnb9wukjwj8by4on6 X-Rspamd-Queue-Id: 9BF88140008 Authentication-Results: imf09.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf09.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1668819155-171341 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This documents the new /sys/class/bdi//strict_limit knob. Signed-off-by: Stefan Roesch --- Documentation/ABI/testing/sysfs-class-bdi | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 6d2a2fc189dd..68b5d4018c2f 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -55,6 +55,17 @@ Description: mount that is prone to get stuck, or a FUSE mount which cannot be trusted to play fair. + (read-write) +What: /sys/class/bdi//strict_limit +Date: October 2022 +Contact: Stefan Roesch +Description: + Forces per-BDI checks for the share of given device in the write-back + cache even before the global background dirty limit is reached. This + is useful in situations where the global limit is much higher than + affordable for given relatively slow (or untrusted) device. Turning + strictlimit on has no visible effect if max_ratio is equal to 100%. + (read-write) What: /sys/class/bdi//stable_pages_required Date: January 2008