From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx106.postini.com [74.125.245.106]) by kanga.kvack.org (Postfix) with SMTP id 7686D6B00F9 for ; Mon, 27 May 2013 04:24:15 -0400 (EDT) Date: Mon, 27 May 2013 17:24:13 +0900 From: Minchan Kim Subject: Re: [PATCH v5 6/7] mm: Support address range reclaim Message-ID: <20130527082413.GC5157@blaptop> References: <1368084089-24576-1-git-send-email-minchan@kernel.org> <1368084089-24576-7-git-send-email-minchan@kernel.org> <20130521173332.637942da.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130521173332.637942da.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rik van Riel , Michael Kerrisk , Dave Hansen , Namhyung Kim , Minkyung Kim On Tue, May 21, 2013 at 05:33:32PM -0700, Andrew Morton wrote: > On Thu, 9 May 2013 16:21:28 +0900 Minchan Kim wrote: > > > This patch adds address range reclaim of a process. > > The requirement is following as, > > > > Like webkit1, it uses a address space for handling multi tabs. > > IOW, it uses *one* process model so all tabs shares address space > > of the process. In such scenario, per-process reclaim is rather > > coarse-grained so this patch supports more fine-grained reclaim > > for being able to reclaim target address range of the process. > > For reclaim target range, you should use following format. > > > > echo [addr] [size-byte] > /proc/pid/reclaim > > > > The addr should be page-aligned. > > > > So now reclaim konb's interface is following as. > > > > echo file > /proc/pid/reclaim > > reclaim file-backed pages only > > > > echo anon > /proc/pid/reclaim > > reclaim anonymous pages only > > > > echo all > /proc/pid/reclaim > > reclaim all pages > > > > echo 0x100000 8K > /proc/pid/reclaim > > reclaim pages in (0x100000 - 0x102000) > > This might be going a bit far. The application itself can be modified > to use fadvise/madvise/whatever to release unused pages and that's a > better interface. I agree. The webkit should be smarter and it's going on afaik but let's think another usecase that makes snapshot image scenario I mentioned in previous reply. Admin should discard NOT-IMPORTANT pages without modifying application's code. In addition, maybe we need madvise(MADV_SWAPOUT_NOT_DONTNEED) for anonymous pages if we don't have such feature. > > Athough it's a bit of a pipe-dream, I do think we should encourage > userspace to go this path, rather than providing ways for hacky admin > tools to go poking around in /proc/pid/maps and whacking apps > externally. > > -- > 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 -- 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/ . Don't email: email@kvack.org