From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 793546B0069 for ; Fri, 14 Oct 2016 09:46:17 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id u84so110111354pfj.6 for ; Fri, 14 Oct 2016 06:46:17 -0700 (PDT) Received: from mail-pf0-x243.google.com (mail-pf0-x243.google.com. [2607:f8b0:400e:c00::243]) by mx.google.com with ESMTPS id zz3si15564166pac.76.2016.10.14.06.46.16 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 14 Oct 2016 06:46:16 -0700 (PDT) Received: by mail-pf0-x243.google.com with SMTP id r16so7305665pfg.3 for ; Fri, 14 Oct 2016 06:46:16 -0700 (PDT) From: Minchan Kim Date: Fri, 14 Oct 2016 22:46:04 +0900 Subject: Re: [PATCH v2] mm: exclude isolated non-lru pages from NR_ISOLATED_ANON or NR_ISOLATED_FILE. Message-ID: <20161014134604.GA2179@blaptop> References: <1476340749-13281-1-git-send-email-ming.ling@spreadtrum.com> <20161013080936.GG21678@dhcp22.suse.cz> <20161014083219.GA20260@spreadtrum.com> <20161014113044.GB6063@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161014113044.GB6063@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Ming Ling , akpm@linux-foundation.org, mgorman@techsingularity.net, vbabka@suse.cz, hannes@cmpxchg.org, baiyaowei@cmss.chinamobile.com, iamjoonsoo.kim@lge.com, minchan@kernel.org, rientjes@google.com, hughd@google.com, kirill.shutemov@linux.intel.com, riel@redhat.com, mgorman@suse.de, aquini@redhat.com, corbet@lwn.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org, orson.zhai@spreadtrum.com, geng.ren@spreadtrum.com, chunyan.zhang@spreadtrum.com, zhizhou.tian@spreadtrum.com, yuming.han@spreadtrum.com, xiajing@spreadst.com Hi, Michal, On Fri, Oct 14, 2016 at 01:30:44PM +0200, Michal Hocko wrote: < snip> > > void putback_movable_pages(struct list_head *l) > > { > > ...... > > /* > > * We isolated non-lru movable page so here we can use > > * __PageMovable because LRU page's mapping cannot have > > * PAGE_MAPPING_MOVABLE. > > */ > > if (unlikely(__PageMovable(page))) { > > VM_BUG_ON_PAGE(!PageIsolated(page), page); > > lock_page(page); > > if (PageMovable(page)) > > putback_movable_page(page); > > else > > __ClearPageIsolated(page); > > unlock_page(page); > > put_page(page); > > } else { > > putback_lru_page(page); > > } > > } > > I am not familiar with this code enough to comment but to me it all > sounds quite subtle. It was due to lacking of page flags on 32bit machine, sadly. Better idea is always welcome. > > > > Why don't you simply mimic what shrink_inactive_list does? Aka count the > > > number of isolated pages and then account them when appropriate? > > > > > I think i am correcting clearly wrong part. So, there is no need to > > describe it too detailed. It's a misunderstanding, and i will add > > more comments as you suggest. > > OK, so could you explain why you prefer to relyon __PageMovable rather > than do a trivial counting during the isolation? I don't get it. Could you elaborate it a bit more? > -- > 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