From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <448E3EA8.3020807@yahoo.com.au> Date: Tue, 13 Jun 2006 14:27:20 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH]: Adding a counter in vma to indicate the number of physical pages backing it References: <1149903235.31417.84.camel@galaxy.corp.google.com> <200606121958.41127.ak@suse.de> <1150141369.9576.43.camel@galaxy.corp.google.com> <200606130551.23825.ak@suse.de> In-Reply-To: <200606130551.23825.ak@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: rohitseth@google.com, Andrew Morton , Linux-mm@kvack.org, Linux-kernel@vger.kernel.org List-ID: Andi Kleen wrote: >On Monday 12 June 2006 21:42, Rohit Seth wrote: > >>I think having this >>information in each vma keeps the impact (of adding new counter) to very >>low. >> >>Second question is to advertize this value to user space. Please let me >>know what suites the most among /proc, /sys or system call (or if there >>is any other mechanism then let me know) for a per process per segment >>related information. >> > >I think we first need to identify the basic need. >Don't see why we even need per VMA information so far. > Exactly. There is no question that walking page tables will be slower than having a counter like your patch does; the question is why we need it. -- Send instant messages to your online friends http://au.messenger.yahoo.com -- 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