From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 12 Jun 2006 09:43:17 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH]: Adding a counter in vma to indicate the number of physical pages backing it In-Reply-To: <1149903235.31417.84.camel@galaxy.corp.google.com> Message-ID: References: <1149903235.31417.84.camel@galaxy.corp.google.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Rohit Seth Cc: Andrew Morton , Linux-mm@kvack.org, Linux-kernel@vger.kernel.org List-ID: On Fri, 9 Jun 2006, Rohit Seth wrote: > There is currently /proc//smaps that prints the detailed > information about the usage of physical pages but that is a very > expensive operation as it traverses all the PTs (for some one who is > just interested in getting that data for each vma). Adding a new counter to a vma may cause a bouncing cacheline etc. I would think that such a counter is far more expensive than occasional scans through the page table because someone is curious about the number of page in use. /proc//numa_maps also uses these scans to determine dirty pages etc. -- 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