Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752484Ab3CAWeX (ORCPT ); Fri, 1 Mar 2013 17:34:23 -0500 Received: from mail-da0-f43.google.com ([209.85.210.43]:50685 "EHLO mail-da0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121Ab3CAWeW (ORCPT ); Fri, 1 Mar 2013 17:34:22 -0500 Date: Fri, 1 Mar 2013 14:33:38 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Simon Jeons cc: Johannes Weiner , dormando , Andrew Morton , Rik van Riel , Seiji Aguchi , Satoru Moriya , Randy Dunlap , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "lwoodman@redhat.com" , Mel Gorman Subject: Re: [PATCH] add extra free kbytes tunable In-Reply-To: <51307583.2020006@gmail.com> Message-ID: References: <511EB5CB.2060602@redhat.com> <20130219152936.f079c971.akpm@linux-foundation.org> <20130222175634.GA4824@cmpxchg.org> <51307354.5000401@gmail.com> <51307583.2020006@gmail.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1030 Lines: 24 On Fri, 1 Mar 2013, Simon Jeons wrote: > On 03/01/2013 05:22 PM, Simon Jeons wrote: > > On 02/23/2013 01:56 AM, Johannes Weiner wrote: > > > Mapped file pages have to get scanned twice before they are reclaimed > > > because we don't have enough usage information after the first scan. > > > > It seems that just VM_EXEC mapped file pages are protected. > > Issue in page reclaim subsystem: > > static inline int page_is_file_cache(struct page *page) > > { > > return !PageSwapBacked(page); > > } > > AFAIK, PG_swapbacked is set if anonymous page added to swap cache, and be > > cleaned if removed from swap cache. So anonymous pages which are reclaimed > > and add to swap cache won't have this flag, then they will be treated as > > s/are/aren't PG_swapbacked != PG_swapcache -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/