From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 04 Oct 2004 13:09:10 +0900 From: IWAMOTO Toshihiro Subject: Re: [RFC] memory defragmentation to satisfy high order allocations In-Reply-To: <20041002183349.GA7986@logos.cnet> References: <20041001190430.GA4372@logos.cnet> <1096667823.3684.1299.camel@localhost> <20041001234200.GA4635@logos.cnet> <20041002.183015.41630389.taka@valinux.co.jp> <20041002183349.GA7986@logos.cnet> MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Message-Id: <20041004040910.DCE4470A2D@sv1.valinux.co.jp> Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: Hirokazu Takahashi , haveblue@us.ibm.com, akpm@osdl.org, linux-mm@kvack.org, piggin@cyberone.com.au, arjanv@redhat.com, linux-kernel@vger.kernel.org List-ID: At Sat, 2 Oct 2004 15:33:49 -0300, Marcelo Tosatti wrote: > > On Sat, Oct 02, 2004 at 06:30:15PM +0900, Hirokazu Takahashi wrote: > 3) At migrate_page_common you assume additional page references > (page_migratable returning -EAGAIN) means the code should try to writeout > the page. > > Is that assumption always valid? > > In theory there is no need to writeout pages when migrating them to > other zones - they will be copied and the dirty information retained (either > in the PageDirty bit or radix tree tag). It's true only when page->private is NULL. Otherwise writeback is necessary to free buffer_head. > I just noticed you do that on further patches (migrate_page_buffer), but AFAICS > the writeout remains. Why arent you using migrate_page_buffer yet? > > I think the final aim should be to remove the need for "pageout()" > completly. Are you going to implement migrate_page_buffer for every file system? I don't think it's worthwhile. > Questions: are there any documents on the memory hotplug userspace tools? > Where can I find them? > > Are Iwamoto's test programs available? I've put them at the following URL, but I doubt they are useful for you; there are no documentation for them. http://people.valinux.co.jp/~iwamoto/mh/tests/ -- IWAMOTO Toshihiro -- 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: aart@kvack.org