From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id D67567CA0 for ; Thu, 24 Mar 2016 16:59:02 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id 9704E304051 for ; Thu, 24 Mar 2016 14:59:02 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id 83wyptkHoLaI6gXM for ; Thu, 24 Mar 2016 14:59:00 -0700 (PDT) Date: Fri, 25 Mar 2016 08:58:58 +1100 From: Dave Chinner Subject: Re: Failing XFS memory allocation Message-ID: <20160324215858.GE11812@dastard> References: <56F26CCE.6010502@kyup.com> <20160323124312.GB43073@bfoster.bfoster> <56F29279.70600@kyup.com> <20160323131059.GC43073@bfoster.bfoster> <20160323230002.GY30721@dastard> <56F3B157.2060505@kyup.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <56F3B157.2060505@kyup.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Nikolay Borisov Cc: Brian Foster , xfs@oss.sgi.com On Thu, Mar 24, 2016 at 11:20:23AM +0200, Nikolay Borisov wrote: > On 03/24/2016 01:00 AM, Dave Chinner wrote: > > As it is, yes, the memory allocation problem is with the in-core > > extent tree, and we've known about it for some time. The issue is > > that as memory gets fragmented, the top level indirection array > > grows too large to be allocated as a contiguous chunk. When this > > happens really depends on memory load, uptime and the way the extent > > tree is being modified. > > And what about the following completely crazy idea of switching order > > 3 allocations to using vmalloc? I know this would incur heavy > performance hit, but other than that would it cause correctness issues? > Of course I'm not saying this should be implemented in upstream rather > whether it's worth it having a go for experimenting with this idea. It's not an option as many supported platforms which have extremely limited vmalloc space. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs