From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 30 Jun 2006 16:38:49 -0700 From: Andrew Morton Subject: Re: ZVC/zone_reclaim: Leave 1% of unmapped pagecache pages for file I/O Message-Id: <20060630163849.6365b7a9.akpm@osdl.org> In-Reply-To: References: <200606301219.19473.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: ak@suse.de, schamp@sgi.com, linux-mm@kvack.org List-ID: Christoph Lameter wrote: > > +min_unmapped: > + > +A percentage of the file backed pages in each zone. Zone reclaim will only > +occur if more than this percentage of pages are file backed and unmapped. > +This is to insure that a minimal amount of local pages is still available > +for file I/O even if the node is overallocated. > + > +The default is 1 percent. > + Probably this should have a big "NUMA only" slapped on it so people don't wonder why they don't have such a file. Also, it's nice if the naming of these control files can communicate the units to the operator. In the case of /proc/sys/vm we use _ratio to indicate that it's a proportional control in the 0% - 100% range. So /proc/sys/vm/min_unmapped_ratio would be clearer, and more consistent. -- 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