From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx163.postini.com [74.125.245.163]) by kanga.kvack.org (Postfix) with SMTP id 047AC6B0044 for ; Tue, 18 Dec 2012 10:46:06 -0500 (EST) From: Satoru Moriya Subject: RE: [patch 3/7] mm: vmscan: clarify how swappiness, highest priority, memcg interact Date: Mon, 17 Dec 2012 19:37:55 +0000 Message-ID: <8631DC5930FA9E468F04F3FD3A5D007214AD80D6@USINDEM103.corp.hds.com> References: <1355767957-4913-1-git-send-email-hannes@cmpxchg.org> <1355767957-4913-4-git-send-email-hannes@cmpxchg.org> In-Reply-To: <1355767957-4913-4-git-send-email-hannes@cmpxchg.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Andrew Morton Cc: Rik van Riel , Michal Hocko , Mel Gorman , Hugh Dickins , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" On 12/17/2012 01:12 PM, Johannes Weiner wrote: > A swappiness of 0 has a slightly different meaning for global reclaim=20 > (may swap if file cache really low) and memory cgroup reclaim (never=20 > swap, ever). >=20 > In addition, global reclaim at highest priority will scan all LRU=20 > lists equal to their size and ignore other balancing heuristics. > UNLESS swappiness forbids swapping, then the lists are balanced based=20 > on recent reclaim effectiveness. UNLESS file cache is running low,=20 > then anonymous pages are force-scanned. >=20 > This (total mess of a) behaviour is implicit and not obvious from the=20 > way the code is organized. At least make it apparent in the code flow=20 > and document the conditions. It will be it easier to come up with=20 > sane semantics later. >=20 > Signed-off-by: Johannes Weiner Reviewed-by: Satoru Moriya -- 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