From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 3/4] writeback: nr_dirtied and nr_cleaned in /proc/vmstat Date: Sun, 5 Sep 2010 22:17:15 +0800 Message-ID: <20100905141715.GA9024@localhost> References: <1282963227-31867-1-git-send-email-mrubin@google.com> <1282963227-31867-4-git-send-email-mrubin@google.com> <20100828235029.GA7071@localhost> <20100831074825.GA19358@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Michael Rubin , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "jack@suse.cz" , "riel@redhat.com" , "david@fromorbit.com" , "kosaki.motohiro@jp.fujitsu.com" , "npiggin@kernel.dk" , "hch@lst.de" , "axboe@kernel.dk" To: Andrew Morton Return-path: Content-Disposition: inline In-Reply-To: <20100831074825.GA19358@localhost> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Tue, Aug 31, 2010 at 03:48:25PM +0800, Wu Fengguang wrote: > > > The output format is quite different from /proc/vmstat. > > > Do we really need to "Node X", ":" and "times" decorations? > > > > Node X is based on the meminfo file but I agree it's redundant information. > > Thanks. In the same directory you can find a different style example > /sys/devices/system/node/node0/numastat :) If ever the file was named > vmstat! In the other hand, shall we put the numbers there? I'm confused.. With wider use of NUMA, I'm expecting more interests to put /proc/vmstat items into /sys/devices/system/node/node0/. What shall we do then? There are several possible options: - just put the /proc/vmstat items into nodeX/numastat - create nodeX/vmstat and make numastat a symlink to vmstat - create nodeX/vmstat and remove numastat in future Any suggestions? > > > And the "_PAGES" in NR_FILE_PAGES_DIRTIED looks redundant to > > > the "_page" in node_page_state(). It's a bit long to be a pleasant > > > name. NR_FILE_DIRTIED/NR_CLEANED looks nicer. > > > > Yeah. Will fix. > > Thanks. This is kind of nitpick, however here is another name by > Jan Kara: BDI_WRITTEN. BDI_WRITTEN may not be a lot better than > BDI_CLEANED, but here is a patch based on Jan's code. I'm cooking > more patches that make use of this per-bdi counter to estimate the > bdi's write bandwidth, and to further decide the optimal (large) > writeback chunk size as well as to do IO-less balance_dirty_pages(). > > Basically BDI_WRITTEN and NR_CLEANED are accounting for the same > thing in different dimensions. So it would be good if we can use > the same naming scheme to avoid confusing users: either to use > BDI_WRITTEN and NR_WRITTEN, or use BDI_CLEANED and NR_CLEANED. > What's your opinion? I tend to prefer *_WRITTEN now. - *_WRITTEN reminds the users about IO, *_CLEANED is less so obvious. - *_CLEANED seems to be paired with NR_DIRTIED, this could be misleading to the users. The fact is, dirty pages may either be written to disk, or dropped (by truncate). Thanks, Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org