From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx134.postini.com [74.125.245.134]) by kanga.kvack.org (Postfix) with SMTP id A7E1C6B0031 for ; Thu, 6 Jun 2013 13:17:35 -0400 (EDT) Received: by mail-ob0-f171.google.com with SMTP id dn14so5121624obc.30 for ; Thu, 06 Jun 2013 10:17:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <0000013f19d7a21d-0bc478a9-c65b-4d66-a774-266b17bcde2a-000000@email.amazonses.com> References: <1370445037-24144-1-git-send-email-aarcange@redhat.com> <1370445037-24144-2-git-send-email-aarcange@redhat.com> <51AFA185.9000909@gmail.com> <0000013f161c3f42-14ae4d9d-fd85-47dd-ba80-896e1e84a6fe-000000@email.amazonses.com> <51AFA786.1040608@gmail.com> <0000013f19d7a21d-0bc478a9-c65b-4d66-a774-266b17bcde2a-000000@email.amazonses.com> From: KOSAKI Motohiro Date: Thu, 6 Jun 2013 13:17:14 -0400 Message-ID: Subject: Re: [PATCH 1/7] mm: remove ZONE_RECLAIM_LOCKED Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrea Arcangeli , "linux-mm@kvack.org" , Mel Gorman , Rik van Riel , Hugh Dickins , Richard Davies , Shaohua Li , Rafael Aquini > How does nr_to_reclaim limit the concurrency of zone reclaim? No, it doesn't prevent concurrent reclaim itself. It only prevents cuncurrent reclaim much much pages rather than SWAP_CLUSTER_MAX. note, zone reclaim uses priority 4 by default. > What happens if multiple processes are allocating from the same zone and > they all go into direct reclaim and therefore hit zone reclaim? At zone reclaim was created, 16 (1<<4) concurrent reclaim may drop all page cache because zone reclaim uses priority 4 by default. However, now we have reckaim bail out logic. So, priority 4 doesn't directly mean each zone reclaim drop 1/16 caches. -- 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