From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 22 Feb 2008 12:31:00 +0900 (JST) Message-Id: <20080222.123100.54101482.taka@valinux.co.jp> Subject: [RFC] Block I/O Cgroup From: Hirokazu Takahashi In-Reply-To: <20080221184450.c30f24d6.kamezawa.hiroyu@jp.fujitsu.com> References: <20080221182156.63e5fc25.kamezawa.hiroyu@jp.fujitsu.com> <47BD4438.4030203@linux.vnet.ibm.com> <20080221184450.c30f24d6.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: kamezawa.hiroyu@jp.fujitsu.com Cc: balbir@linux.vnet.ibm.com, hugh@veritas.com, linux-mm@kvack.org, yamamoto@valinux.co.jp, riel@redhat.com List-ID: Hi, It'll be great if you make the feature --- page to mem_cgroup mapping mechanism --- generic, which will make it easy to implement a Block I/O controller. With this feature, you can easily determine the origin cgroup from the page which is going to start I/O. mem_cgroup block_io_cgroup ^ ^ | | | | | | | +------->page<----+ V ^ io_context | ^ | | bio ----------+ Every page should be associated with the proper block_io_cgroup when the need arises. The simplest way is to make it at the same point as mem_cgroups does. It's also possible to do this when the pages get dirtied. > > > But yes. I'm afraid of lock contention very much. I'll find another lock-less way > > > if necessary. One idea is map each area like sparsemem_vmemmap for 64bit systems. > > > Now, I'm convinced that it will be complicated ;) > > > > > > > The radix tree base is lockless (it uses RCU), so we might have a partial > > solution to the locking problem. But it's unchartered territory, so no one knows. > > > > > I'd like to start from easy way and see performance. > > > > > > > Sure, please keep me in the loop as well. > > > Okay, I'll do my best. > > Thanks, > -Kame Thank you, Hirokazu Takahashi. -- 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