From patchwork Sat Nov 19 00:52:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13049468 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 E956AC433FE for ; Sat, 19 Nov 2022 01:27:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 650176B0072; Fri, 18 Nov 2022 20:27:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 600576B0073; Fri, 18 Nov 2022 20:27:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4EED36B0074; Fri, 18 Nov 2022 20:27:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 3EEB66B0072 for ; Fri, 18 Nov 2022 20:27:41 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 0F2FF401D4 for ; Sat, 19 Nov 2022 01:27:41 +0000 (UTC) X-FDA: 80148454722.19.D4929C2 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf20.hostedemail.com (Postfix) with ESMTP id 910921C0006 for ; Sat, 19 Nov 2022 01:27:40 +0000 (UTC) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 6FA0819380D8; 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 09/20] mm: document /sys/class/bdi//max_bytes knob Date: Fri, 18 Nov 2022 16:52:04 -0800 Message-Id: <20221119005215.3052436-10-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=1668821260; a=rsa-sha256; cv=none; b=I6GeCZrkoM2ce/Ou+sGB1zZVFah3SNgTKjvgIcugu02lrkIV34w+pH0uGwBbgb1eU5GIu6 v3Waze6+NcicbJYnX3eWMrBYEick7OahMASfVXDfieU4zxOG4E/NpTaj8nRdCAQxSSQdFZ 6Jvve8eUttcrbPiHVYzSEivmkJOIjMY= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf20.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=1668821260; 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=FG2YZJniK6WQyGMVTRehiSJED6hFD5pcUkGd65cLNIA=; b=uLmiE5NNJ2ilkx+rjA5WC0xtVKJC4z7SPHb6EFXY0ZJwwujZ+f8LcBwbKKZ+12z0TA6JU6 BgHijoWME4lhQ4GfJXnk6uZpCL0uo4OznFifTAS6ouBDN1yAxLhuZ4UsEHdmQY6DNu/gBA EjE/BOMfmKCHPYAoFfwOuMoimjeUIFU= Authentication-Results: imf20.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf20.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-Stat-Signature: 4steptaaqpuffsnzt1hq7rbb9idxszz3 X-Rspamd-Queue-Id: 910921C0006 X-Rspamd-Server: rspam11 X-HE-Tag: 1668821260-66061 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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//max_bytes knob. Signed-off-by: Stefan Roesch --- Documentation/ABI/testing/sysfs-class-bdi | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 68b5d4018c2f..580f723de049 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -56,6 +56,20 @@ Description: be trusted to play fair. (read-write) + +What: /sys/class/bdi//max_bytes +Date: October 2022 +Contact: Stefan Roesch +Description: + Allows limiting a particular device to use not more than the + given 'max_bytes' of the write-back cache. This is useful in + situations where we want to avoid one device taking all or + most of the write-back cache. For example in case of an NFS + mount that is prone to get stuck, a FUSE mount which cannot be + trusted to play fair, or a nbd device. + + (read-write) + What: /sys/class/bdi//strict_limit Date: October 2022 Contact: Stefan Roesch