From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 869526B038B for ; Thu, 16 Mar 2017 11:01:56 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id l37so8890649wrc.7 for ; Thu, 16 Mar 2017 08:01:56 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id d2si6992003wrc.143.2017.03.16.08.01.55 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 16 Mar 2017 08:01:55 -0700 (PDT) Date: Thu, 16 Mar 2017 16:01:53 +0100 From: Michal Hocko Subject: Re: MAP_POPULATE vs. MADV_HUGEPAGES Message-ID: <20170316150153.GK30501@dhcp22.suse.cz> References: <20170316123449.GE30508@dhcp22.suse.cz> <4e1011d9-aef3-5cd7-1424-b81aa79128cb@scylladb.com> <20170316144832.GJ30501@dhcp22.suse.cz> <53e8bb71-5bf2-2690-f605-aa4d5d50eb90@scylladb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53e8bb71-5bf2-2690-f605-aa4d5d50eb90@scylladb.com> Sender: owner-linux-mm@kvack.org List-ID: To: Avi Kivity Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu 16-03-17 16:56:34, Avi Kivity wrote: > On 03/16/2017 04:48 PM, Michal Hocko wrote: > >On Thu 16-03-17 15:26:54, Avi Kivity wrote: [...] > >>>What is the THP defrag mode > >>>(/sys/kernel/mm/transparent_hugepage/defrag)? > >>The default (always). > >the default has changed since then because the THP faul latencies were > >just too large. Currently we only allow madvised VMAs to go stall and > >even then we try hard to back off sooner rather than later. See > >444eb2a449ef ("mm: thp: set THP defrag by default to madvise and add a > >stall-free defrag option") merged in 4.4 > > I see, thanks. So the 4.4 behavior is better mostly due to not trying so > hard. Please note there were many other patches in the compaction code as well. -- Michal Hocko SUSE Labs -- 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