From patchwork Mon Oct 17 18:13:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13009236 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 2CA49C4332F for ; Mon, 17 Oct 2022 18:16:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 17C2B8E0008; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 129868E0007; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E6E568E0008; Mon, 17 Oct 2022 14:16:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id D2D016B007B for ; Mon, 17 Oct 2022 14:16:45 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id AB1AB1A0DED for ; Mon, 17 Oct 2022 18:16:45 +0000 (UTC) X-FDA: 80031247170.28.2A9E695 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf07.hostedemail.com (Postfix) with ESMTP id 4215A40033 for ; Mon, 17 Oct 2022 18:16:45 +0000 (UTC) Received: by dev1180.prn1.facebook.com (Postfix, from userid 425415) id 3F2D039C99C4; Mon, 17 Oct 2022 11:13:56 -0700 (PDT) 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, willy@infradead.org, hch@infradead.org Subject: [RFC PATCH v2 09/14] mm: document /sys/class/bdi//max_bytes knob Date: Mon, 17 Oct 2022 11:13:32 -0700 Message-Id: <20221017181337.3884657-10-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221017181337.3884657-1-shr@devkernel.io> References: <20221017181337.3884657-1-shr@devkernel.io> MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666030605; 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=2ryPz0io6pLGWtxWXqrA+OxeWtn9zn8Yyhsbs7jFNSysFy4UqQ0BwexClGSuvN1570NEPX 3Opf+QRXLnzi8nYtiU0zkQK6hjqJ9uJ+eByxvaeFOIIJ+sxGqPptQ3rwL+rY66KGd3z1j9 DtHqI/47N0bTBOHUr5mVeGtdwFRGUgs= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf07.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666030605; a=rsa-sha256; cv=none; b=rcmuZ8bbJ3vcqROiW9uFeR9O0kLbjzowAahlAI+kqjvuZvKsV1SAiNqO9UQRoG3i1X+iDi jn2JjGZWzWMixw4PFaPivVeBzbUF1scohtAABII6nqNQ4pWtMngX42akFD9Wum5qr80Bbe +zFD8SJ1hXcXz7w3cL+o+Pn8GY/FC0U= Authentication-Results: imf07.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf07.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4215A40033 X-Rspam-User: X-Stat-Signature: tu74p3jms7nck9qzxncojwy1gnft89ig X-HE-Tag: 1666030605-36052 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