From patchwork Mon Oct 17 18:13:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13009230 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 3C7F5C43217 for ; Mon, 17 Oct 2022 18:16:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C28996B0075; Mon, 17 Oct 2022 14:16:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B3CD16B0078; Mon, 17 Oct 2022 14:16:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A02906B007B; Mon, 17 Oct 2022 14:16:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 90F546B0075 for ; Mon, 17 Oct 2022 14:16:36 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 66B70A5B3F for ; Mon, 17 Oct 2022 18:16:36 +0000 (UTC) X-FDA: 80031246792.30.478BAD3 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf19.hostedemail.com (Postfix) with ESMTP id EFF931A0032 for ; Mon, 17 Oct 2022 18:16:34 +0000 (UTC) Received: by dev1180.prn1.facebook.com (Postfix, from userid 425415) id 1D71F39C99B8; 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 03/14] mm: document /sys/class/bdi//strict_limit knob Date: Mon, 17 Oct 2022 11:13:26 -0700 Message-Id: <20221017181337.3884657-4-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-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666030595; a=rsa-sha256; cv=none; b=IRys7+mt62rk1/2TqIRU103/mlYj3Qvo1WcDGRn+Qqul4ZVbBi+mSG033UCCA1/XuQlNeC 5tke2U3oKO3AmHeFLUbcHDx7v3S3u+Ht+hd3RFIDPdR9M/O2LahY57wsWZuuVOTSePpcYm ZAwXBCRCvEtBUIrSt9NOY6U+ABxddeU= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; spf=neutral (imf19.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-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666030595; 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=NmX1Xsmgphe32AyyyxQM2RDzf7ixXeavSZceK8TYmJwLRhQLw/LNzOYY+InCEH+YJyHYU8 Qcseb+kExDoe8iQUz3DWmEN34KIaS9vnnfzRqwLwKytIhDrwfY9qVaKcImd+6drwpvvw2f LMAQr9gW8tfU2/GAsEPwuvXzSUqlpLo= X-Stat-Signature: 5m9bzsskidsauwszwtyandawwdcgpz9n X-Rspamd-Queue-Id: EFF931A0032 X-Rspam-User: X-Rspamd-Server: rspam03 Authentication-Results: imf19.hostedemail.com; dkim=none; spf=neutral (imf19.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: 1666030594-316049 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