From patchwork Mon Oct 24 19:05:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13017988 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 F331BC38A2D for ; Mon, 24 Oct 2022 19:06:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5901D940007; Mon, 24 Oct 2022 15:06:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4AE6A94000F; Mon, 24 Oct 2022 15:06:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 133E394000C; Mon, 24 Oct 2022 15:06:31 -0400 (EDT) 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 E2DFF940007 for ; Mon, 24 Oct 2022 15:06:31 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 9A2101A0B75 for ; Mon, 24 Oct 2022 19:06:31 +0000 (UTC) X-FDA: 80056774182.25.5F26903 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf08.hostedemail.com (Postfix) with ESMTP id 3C8CA160004 for ; Mon, 24 Oct 2022 19:06:31 +0000 (UTC) Received: by dev1180.prn1.facebook.com (Postfix, from userid 425415) id 5639D3ED590C; Mon, 24 Oct 2022 12:06:12 -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 v3 03/14] mm: document /sys/class/bdi//strict_limit knob Date: Mon, 24 Oct 2022 12:05:52 -0700 Message-Id: <20221024190603.3987969-4-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221024190603.3987969-1-shr@devkernel.io> References: <20221024190603.3987969-1-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=1666638391; 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=w6YpVQQSxlDA3w+M4b8tdsespQH1IXd6hGycfdHgGcdnKJmrGnp0t2xOgNUva4B/hHry17 cOAMBBC0NHOGyj8+ro7Gsyg/djaO2S5p+TxHqL/HqOWdAgCYe6wkgDO9ANke/tfzVxQpfU lRWohNa+3ro6bSENEjtfVHGBgh9JJj8= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf08.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=1666638391; a=rsa-sha256; cv=none; b=fgtixDWdaBfwA8ePTSdMtTYC6S7TLT8617tQd0vW9MFmcmEdQ7K1QXvgMSdqUBfpdnVrxi lruTpE/M223NU4F50OfE5T5PeBDAlzjc9AghnMgq5kkYrNgG6xwUkuq7gVfWLL61obJ/Os KHT92fdxMlnZhaXs8Wbii/7wBI193J0= X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 3C8CA160004 X-Rspam-User: Authentication-Results: imf08.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf08.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io X-Stat-Signature: k4i9qwwqehfif5nqkc7xpu7xxoiyhh15 X-HE-Tag: 1666638391-143850 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//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