From patchwork Sat Nov 19 00:52:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13049520 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 8BDDBC4332F for ; Sat, 19 Nov 2022 02:15:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0AEA76B0073; Fri, 18 Nov 2022 21:15:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 037416B0072; Fri, 18 Nov 2022 21:15:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D8A486B0072; Fri, 18 Nov 2022 21:15:42 -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 C383C6B0072 for ; Fri, 18 Nov 2022 21:15:42 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9666A40B40 for ; Sat, 19 Nov 2022 02:15:42 +0000 (UTC) X-FDA: 80148575724.23.F835D4F Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf13.hostedemail.com (Postfix) with ESMTP id 282492000A for ; Sat, 19 Nov 2022 02:15:41 +0000 (UTC) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 8506219380E4; 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 14/20] mm: document /sys/class/bdi//min_bytes knob Date: Fri, 18 Nov 2022 16:52:09 -0800 Message-Id: <20221119005215.3052436-15-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-Authentication-Results: i=1; imf13.hostedemail.com; dkim=none; spf=neutral (imf13.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=1668824142; a=rsa-sha256; cv=none; b=d+6XAQ/rLBeHVB0TrCTboRkVXIiL5ozXunF2hHKJsrlLrAZE40DwcUTEsvBPklJx7caMXI o/voc0t6GIkLfui68s+3RQSxOG92A+SuxR3nXXXQTIjuvQlwnz8DSxTUF5zZKKBS2j74u7 wQFGwSIx83WUVjT3QxvA5ystW4I7qoQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668824142; 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=3EUi6jPj2vZbV6ealsadFNrxvkct4936SBuSwS/JJic=; b=JtcdjI004QN8DBnBdTkcOvhcfE8j84JLEBHGDArT/zBwQh0x1Egx71PpOQlkznApR8oy// 4LPcykcY2H3pGCi81HkGC6K+hZhcYlAjPTFcU78nXzS5w1jrAKVgopnbLmZEe6xfbyBV+n KH5LHEXE86NyiDOqO2xk1xGQZx8NsQM= Authentication-Results: imf13.hostedemail.com; dkim=none; spf=neutral (imf13.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-Rspamd-Server: rspam02 X-Rspam-User: X-Stat-Signature: biofh3c9f5xa8wcpjiyyhzigqdp5rk6d X-Rspamd-Queue-Id: 282492000A X-HE-Tag: 1668824141-871737 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000342, 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//min_bytes knob. Signed-off-by: Stefan Roesch --- Documentation/ABI/testing/sysfs-class-bdi | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 580f723de049..bec996e29565 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -57,6 +57,21 @@ Description: (read-write) +What: /sys/class/bdi//min_bytes +Date: October 2022 +Contact: Stefan Roesch +Description: + Under normal circumstances each device is given a part of the + total write-back cache that relates to its current average + writeout speed in relation to the other devices. + + The 'min_bytes' parameter allows assigning a minimum + percentage of the write-back cache to a particular device + expressed in bytes. + For example, this is useful for providing a minimum QoS. + + (read-write) + What: /sys/class/bdi//max_bytes Date: October 2022 Contact: Stefan Roesch