From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755977AbcECKH5 (ORCPT ); Tue, 3 May 2016 06:07:57 -0400 Received: from mail-lf0-f44.google.com ([209.85.215.44]:34951 "EHLO mail-lf0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755867AbcECKHx (ORCPT ); Tue, 3 May 2016 06:07:53 -0400 Date: Tue, 3 May 2016 13:07:48 +0300 From: "Kirill A. Shutemov" To: Michal Hocko Cc: Dave Hansen , Vlastimil Babka , "Odzioba, Lukasz" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "Shutemov, Kirill" , "Anaczkowski, Lukasz" Subject: Re: mm: pages are not freed from lru_add_pvecs after process termination Message-ID: <20160503100748.GA31787@node.shutemov.name> References: <5720F2A8.6070406@intel.com> <572766A7.9090406@suse.cz> <20160502150109.GB24419@node.shutemov.name> <572776EF.2070804@intel.com> <20160502160250.GD24419@node.shutemov.name> <20160503073757.GA28046@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160503073757.GA28046@dhcp22.suse.cz> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 03, 2016 at 09:37:57AM +0200, Michal Hocko wrote: > On Mon 02-05-16 19:02:50, Kirill A. Shutemov wrote: > > On Mon, May 02, 2016 at 08:49:03AM -0700, Dave Hansen wrote: > > > On 05/02/2016 08:01 AM, Kirill A. Shutemov wrote: > > > > On Mon, May 02, 2016 at 04:39:35PM +0200, Vlastimil Babka wrote: > > > >> On 04/27/2016 07:11 PM, Dave Hansen wrote: > > > >>> 6. Perhaps don't use the LRU pagevecs for large pages. It limits the > > > >>> severity of the problem. > > > >> > > > >> I think that makes sense. Being large already amortizes the cost per base > > > >> page much more than pagevecs do (512 vs ~22 pages?). > > > > > > > > We try to do this already, don't we? Any spefic case where we have THPs on > > > > pagevecs? > > > > > > Lukas was hitting this on a RHEL 7 era kernel. In his kernel at least, > > > I'm pretty sure THP's were ending up on pagevecs. Are you saying you > > > don't think we're doing that any more? > > > > As Vlastimil pointed, we do. It need to be fixed, I think. > > It seems that offloading the draining to the vmstat context doesn't look > terribly bad. Don't we rather want to go that way? Maybe. My knowledge about lru cache is limited. -- Kirill A. Shutemov