From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id DF1CE6B0169 for ; Mon, 22 Aug 2011 03:52:51 -0400 (EDT) Date: Mon, 22 Aug 2011 08:52:46 +0100 From: Chris Webb Subject: Re: Host where KSM appears to save a negative amount of memory Message-ID: <20110822075246.GA2021@arachsys.com> References: <20110821085614.GA3957@arachsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: kvm@vger.kernel.org, linux-mm@kvack.org Hugh Dickins writes: > KSM chooses to show the numbers pages_shared and pages_sharing as > exclusive counts: pages_sharing indicates the saving being made. So it > would be perfectly reasonable to add those two numbers together to get > the "total" number of pages sharing, the number you expected it to show; > but it doesn't make sense to subtract shared from sharing. Hi. Many thanks for your helpful and detailed explanation. I've fixed our monitoring to correctly use just pages_sharing to measure the savings. I think I just assumed the meanings of pages_shared and pages_sharing from their names. This means that ksm has been saving even more memory than we thought on our hosts in the past! Best wishes, Chris. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org