From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id CB9BD8D0039 for ; Thu, 24 Feb 2011 19:51:53 -0500 (EST) Subject: Re: too big min_free_kbytes From: Shaohua Li In-Reply-To: <20110224140413.GA5633@random.random> References: <20110126163655.GU18984@csn.ul.ie> <20110126174236.GV18984@csn.ul.ie> <20110127134057.GA32039@csn.ul.ie> <20110127152755.GB30919@random.random> <20110203025808.GJ5843@random.random> <20110214022524.GA18198@sli10-conroe.sh.intel.com> <20110222142559.GD15652@csn.ul.ie> <1298438954.19589.7.camel@sli10-conroe> <20110223144509.GG31195@random.random> <1298534927.19589.41.camel@sli10-conroe> <20110224140413.GA5633@random.random> Content-Type: text/plain; charset="UTF-8" Date: Fri, 25 Feb 2011 08:51:49 +0800 Message-ID: <1298595109.19589.46.camel@sli10-conroe> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Mel Gorman , Andrew Morton , linux-mm , "Chen, Tim C" , Rik van Riel , "Shi, Alex" , Andi Kleen On Thu, 2011-02-24 at 22:04 +0800, Andrea Arcangeli wrote: > On Thu, Feb 24, 2011 at 04:08:47PM +0800, Shaohua Li wrote: > > with madvise, the min_free_kbytes is still high (same as the 'always' > > case). The result is still we have about 50M memory is reserved. you can > > try at your machine with boot option 'mem=2G' and check the zoneinfo > > output. > > yes I know. The objective of that test was exactly to know if the > problem is higher memory footprint because of THP or only the > anti-frag/min_free_kbytes which would still be present with the > "madvise" setting (anti-frag is only shutdown by the "never" > setting). If you still have the out of memory with madvise, then you > can keep THP enabled "always" and then "echo 16384 > > /proc/sys/vm/min_free_kbytes", it should work fine then even with THP > always mode then, no need to disable THP (simply you won't have a good > guarantee that anti-frag is functional so the hugepage usage will be > reduced over time compared to the default min_free_kbytes that enables > anti-frag fully). I can disable THP or set the min_free_kbytes manually in our test, but just wonder if it's possible we can avoid the memory waste even with THP enabled, because this will make more people enable it by default. If you don't consider this is a problem, we can disable THP. -- 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