From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 8 Jun 2007 15:06:02 +0900 From: KAMEZAWA Hiroyuki Subject: Re: memory unplug v4 intro [1/6] migration without mm->sem Message-Id: <20070608150602.78f07b34.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20070608143531.411c76df.kamezawa.hiroyu@jp.fujitsu.com> <20070608143844.569c2804.kamezawa.hiroyu@jp.fujitsu.com> <20070608145435.4fa7c9b6.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, mel@csn.ul.ie, y-goto@jp.fujitsu.com, hugh@veritas.com List-ID: On Thu, 7 Jun 2007 22:57:19 -0700 (PDT) Christoph Lameter wrote: > > Ah, maybe ok. But scattering codes around rmap in several files is ok ? > > No. Lets try to keep the changes to rmap minimal. > Okay, will do my best. > > > Could you avoid these checks by having page_referend_one fail > > > appropriately on the dummy vma? > > > > > Hmm, Is this better ? > > == > > static int page_referenced_one(struct page *page, > > struct vm_area_struct *vma, unsigned int *mapcount) > > { > > struct mm_struct *mm = vma->vm_mm; > > unsigned long address; > > pte_t *pte; > > spinlock_t *ptl; > > int referenced = 0; > > > > + if(is_dummy_vma(vma)) > > + return 0; > > The best solution would be if you could fill the dummy vma with such > values that will give you the intended result without having to modify > page_referenced_one. If you can make vma_address() fail then you have > what you want. F.e. setting vma->vm_end to zero should do it. (is it not > already zero?) > > Hmm, maybe your option will work. I'll try it in the next set. My concern is that almost all people will never imagine anon_vma can includes dummy_vma in some special case.. -Kame -Kame -- 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