From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 46D3B6B0071 for ; Tue, 23 Nov 2010 00:30:05 -0500 (EST) Received: by iwn10 with SMTP id 10so909380iwn.14 for ; Mon, 22 Nov 2010 21:30:03 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20101122210132.be9962c7.akpm@linux-foundation.org> References: <20101122141449.9de58a2c.akpm@linux-foundation.org> <20101122210132.be9962c7.akpm@linux-foundation.org> Date: Tue, 23 Nov 2010 14:23:33 +0900 Message-ID: Subject: Re: [RFC 1/2] deactive invalidated pages From: Minchan Kim Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: linux-mm , LKML , Peter Zijlstra , Rik van Riel , KOSAKI Motohiro , Johannes Weiner , Nick Piggin List-ID: On Tue, Nov 23, 2010 at 2:01 PM, Andrew Morton wrote: > On Tue, 23 Nov 2010 13:52:05 +0900 Minchan Kim wr= ote: > >> >> +/* >> >> + * Function used to forecefully demote a page to the head of the ina= ctive >> >> + * list. >> >> + */ >> > >> > This comment is wrong? __The page gets moved to the _tail_ of the >> > inactive list? >> >> No. I add it in _head_ of the inactive list intentionally. >> Why I don't add it to _tail_ is that I don't want to be aggressive. >> The page might be real working set. So I want to give a chance to >> activate it again. > > Well.. =A0why? =A0The user just tried to toss the page away altogether. = =A0If > the kernel wasn't able to do that immediately, the best it can do is to > toss the page away asap? > >> If it's not working set, it can be reclaimed easily and it can prevent >> active page demotion since inactive list size would be big enough for >> not calling shrink_active_list. > > What is "working set"? =A0Mapped and unmapped pagecache, or are you > referring solely to mapped pagecache? I mean it's mapped by other processes. > > If it's mapped pagecache then the user was being a bit silly (or didn't > know that some other process had mapped the file). =A0In which case we > need to decide what to do - leave the page alone, deactivate it, or > half-deactivate it as this patch does. What I want is the half-deactivate. Okay. We will use the result of invalidate_inode_page. If fail happens by page_mapped, we can do half-deactivate. But if fail happens by dirty(ex, writeback), we can add it to tail. Does it make sense? --=20 Kind regards, Minchan Kim -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org