From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 18 Oct 2005 09:50:45 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH 0/2] Page migration via Swap V2: Overview In-Reply-To: <43549815.9090001@jp.fujitsu.com> Message-ID: References: <20051018004932.3191.30603.sendpatchset@schroedinger.engr.sgi.com> <43549815.9090001@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, lhms-devel@lists.sourceforge.net, jschopp@austin.ibm.com, Andrew Morton List-ID: On Tue, 18 Oct 2005, KAMEZAWA Hiroyuki wrote: > Because sys_mbind() acquires mm->mmap_sem, once page is unmapped, > all accesses to the page are blocked. > > So, even if the range contains hot pages, there will not be > hard-to-be-swapped-out pages. right ? There may be locked pages and maybe pages that are continually busy. > sys_mbind() can aquire mm->mmap_sem for migrating *a process's page*, > but memory-hotplug cannot aquire the lock for migrating a chunk of pages. I did mbind first because it is the less invasive. The primary reason to acquire mmap_sem is to be able to walk the vma areas. > I think we'll need radix_tree_replace for migating arbitrary chunk of pages, > anyway. Likely. Ultimately I would like to see the direct migration work. -- 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