From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751611AbdB0QcR (ORCPT ); Mon, 27 Feb 2017 11:32:17 -0500 Received: from mx2.suse.de ([195.135.220.15]:53061 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbdB0QcQ (ORCPT ); Mon, 27 Feb 2017 11:32:16 -0500 Date: Mon, 27 Feb 2017 17:32:12 +0100 From: Michal Hocko To: Shaohua Li Cc: Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kernel-team@fb.com, hughd@google.com, hannes@cmpxchg.org, riel@redhat.com, mgorman@techsingularity.net, akpm@linux-foundation.org Subject: Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Message-ID: <20170227163212.GN26504@dhcp22.suse.cz> References: <14b8eb1d3f6bf6cc492833f183ac8c304e560484.1487965799.git.shli@fb.com> <20170227063315.GC23612@bbox> <20170227161907.GC62304@shli-mbp.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170227161907.GC62304@shli-mbp.local> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 27-02-17 08:19:08, Shaohua Li wrote: > On Mon, Feb 27, 2017 at 03:33:15PM +0900, Minchan Kim wrote: [...] > > > --- a/include/linux/rmap.h > > > +++ b/include/linux/rmap.h > > > @@ -298,6 +298,6 @@ static inline int page_mkclean(struct page *page) > > > #define SWAP_AGAIN 1 > > > #define SWAP_FAIL 2 > > > #define SWAP_MLOCK 3 > > > -#define SWAP_LZFREE 4 > > > +#define SWAP_DIRTY 4 > > > > I still don't convinced why we should introduce SWAP_DIRTY in try_to_unmap. > > https://marc.info/?l=linux-mm&m=148797879123238&w=2 > > > > We have been SetPageMlocked in there but why cannot we SetPageSwapBacked > > in there? It's not a thing to change LRU type but it's just indication > > we found the page's status changed in late. > > This one I don't have strong preference. Personally I agree with Johannes, > handling failure in vmscan sounds better. But since the failure handling is > just one statement, this probably doesn't make too much difference. If Johannes > and you made an agreement, I'll follow. FWIW I like your current SWAP_DIRTY and the later handling at the vmscan level more. -- Michal Hocko SUSE Labs