From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 918F66B0005 for ; Fri, 1 Mar 2013 17:34:22 -0500 (EST) Received: by mail-pa0-f42.google.com with SMTP id kq12so2083937pab.15 for ; Fri, 01 Mar 2013 14:34:21 -0800 (PST) Date: Fri, 1 Mar 2013 14:33:38 -0800 (PST) From: Hugh Dickins 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> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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