From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 544616B0003 for ; Wed, 30 May 2018 19:57:27 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id c4-v6so11669419pfg.22 for ; Wed, 30 May 2018 16:57:27 -0700 (PDT) Received: from out4438.biz.mail.alibaba.com (out4438.biz.mail.alibaba.com. [47.88.44.38]) by mx.google.com with ESMTPS id i10-v6si28481305pgv.109.2018.05.30.16.57.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 May 2018 16:57:25 -0700 (PDT) From: Yang Shi Subject: [PATCH] doc: add description to dirtytime_expire_seconds Date: Thu, 31 May 2018 07:56:53 +0800 Message-Id: <1527724613-17768-1-git-send-email-yang.shi@linux.alibaba.com> Sender: owner-linux-mm@kvack.org List-ID: To: tytso@mit.edu, corbet@lwn.net, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org commit 1efff914afac8a965ad63817ecf8861a927c2ace ("fs: add dirtytime_expire_seconds sysctl") introduced dirtytime_expire_seconds knob, but there is not description about it in Documentation/sysctl/vm.txt. Add the description for it. Cc: Theodore Ts'o Signed-off-by: Yang Shi --- I didn't dig into the old review discussion about why the description was not added at the first place. I'm supposed every knob under /proc/sys should have a brief description. Documentation/sysctl/vm.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 17256f2..f4f4f9c 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -27,6 +27,7 @@ Currently, these files are in /proc/sys/vm: - dirty_bytes - dirty_expire_centisecs - dirty_ratio +- dirtytime_expire_seconds - dirty_writeback_centisecs - drop_caches - extfrag_threshold @@ -178,6 +179,16 @@ The total available memory is not equal to total system memory. ============================================================== +dirtytime_expire_seconds + +When a lazytime inode is constantly having its pages dirtied, it with an +updated timestamp will never get chance to be written out. This tunable +is used to define when dirty inode is old enough to be eligible for +writeback by the kernel flusher threads. And, it is also used as the +interval to wakeup dirtytime_writeback thread. It is expressed in seconds. + +============================================================== + dirty_writeback_centisecs The kernel flusher threads will periodically wake up and write `old' data -- 1.8.3.1