From patchwork Tue Oct 11 01:00:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13003481 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 30E0DC4332F for ; Tue, 11 Oct 2022 01:01:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 66A878E0001; Mon, 10 Oct 2022 21:01:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5EAAE900003; Mon, 10 Oct 2022 21:01:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2133E8E0001; Mon, 10 Oct 2022 21:01:23 -0400 (EDT) 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 EA3946B007E for ; Mon, 10 Oct 2022 21:01:22 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id BC00E1C11FD for ; Tue, 11 Oct 2022 01:01:22 +0000 (UTC) X-FDA: 80006865204.03.DF0DAF2 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf06.hostedemail.com (Postfix) with ESMTP id 51BBB18001E for ; Tue, 11 Oct 2022 01:01:22 +0000 (UTC) Received: by dev1180.prn1.facebook.com (Postfix, from userid 425415) id F21E234BDDD4; Mon, 10 Oct 2022 18:01:05 -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 Subject: [RFC PATCH v1 03/14] mm: document new /sys/class/bdi//strict_limit knob Date: Mon, 10 Oct 2022 18:00:33 -0700 Message-Id: <20221011010044.851537-4-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221011010044.851537-1-shr@devkernel.io> References: <20221011010044.851537-1-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=1665450082; 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=L4BFLGPsrGNUlpHo4H6rPjV2hbbmB+826O1DKa+6A/VHyje8Co9ALcHg1I8tgIwSw1r0MU YMrdj1gAsgq/S6FbaaQEN8Ru14Shh2BXfKePi/qdlMWeUwZTitHDAGD4gyIkuI6S9RecEd 7MZQypKQUu70mcIemlkQJ0wBqqL7CZ0= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=neutral (imf06.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665450082; a=rsa-sha256; cv=none; b=A2kyD/dUz9Z7x5FEAer+hG8WTnGC5Py26LvnWoKU9ft3u06P3jm7XOJU5ZRrQgPUFTGhGa SGxiDlATleeqbKGGHT8ZuOoeC35i2UEZqJaNpGyn+C/R7sSTdpgakixvwtRt7FtpbIGEft P4d1yoqAQM3T9KkqtPDj75a3GBRESB4= X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 51BBB18001E X-Stat-Signature: 9wkgd5wm9khq9xrqcy8tozm8k4i7zttg Authentication-Results: imf06.hostedemail.com; dkim=none; spf=neutral (imf06.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io; dmarc=none X-HE-Tag: 1665450082-903975 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