From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 25 Feb 2008 17:28:20 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH] radix-tree based page_cgroup. [6/7] radix-tree based page cgroup Message-Id: <20080225172820.1d21df2f.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080225.170229.54211092.taka@valinux.co.jp> References: <20080225155211.f21fb44d.kamezawa.hiroyu@jp.fujitsu.com> <20080225.160540.80745258.taka@valinux.co.jp> <20080225162544.c1b680cc.kamezawa.hiroyu@jp.fujitsu.com> <20080225.170229.54211092.taka@valinux.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hirokazu Takahashi Cc: balbir@linux.vnet.ibm.com, hugh@veritas.com, yamamoto@valinux.co.jp, ak@suse.de, nickpiggin@yahoo.com.au, linux-mm@kvack.org List-ID: On Mon, 25 Feb 2008 17:02:29 +0900 (JST) Hirokazu Takahashi wrote: > > - 28bytes * (2^7) = 3584 bytes. wastes 608 bytes per 512k of user memory. > > - 28bytes * (2^8) = 7168 bytes. wastes 1024 bytes per 1M of user memory. > > > > loss is 0.1%. or any room user for page_cgroup's extra 4 bytes ? > > > > Thanks, > > -Kame > > I feel kernel memory is an expensive resource especially on 32 bit linux > machines. I think this is one of the reasones why a lot of people don't > want to increase the size of page structure. > Maybe the smallest loss case is 2^4. 28bytes * 2^4 * 9 = 4032byes. (use private kmem_cache_alloc() here.) I'll add this config and test it. Thanks, -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