From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx131.postini.com [74.125.245.131]) by kanga.kvack.org (Postfix) with SMTP id 66E0C6B0005 for ; Fri, 1 Mar 2013 19:10:59 -0500 (EST) Received: by mail-ia0-f176.google.com with SMTP id i18so3147849iac.35 for ; Fri, 01 Mar 2013 16:10:58 -0800 (PST) Message-ID: <5131438B.4090507@gmail.com> Date: Sat, 02 Mar 2013 08:10:51 +0800 From: Simon Jeons MIME-Version: 1.0 Subject: Re: [PATCH] add extra free kbytes tunable References: <511EB5CB.2060602@redhat.com> <20130219152936.f079c971.akpm@linux-foundation.org> <20130222175634.GA4824@cmpxchg.org> <51307354.5000401@gmail.com> <51307583.2020006@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins 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 03/02/2013 06:33 AM, Hugh Dickins wrote: > 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 Oh, I see. Thanks Hugh, thanks for your patient. :) In function __add_to_swap_cache if add to radix tree successfully will result in increase NR_FILE_PAGES, why? This is anonymous page instead of file backed page. -- 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