From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 21 Oct 2004 20:09:35 +0100 (BST) From: Hugh Dickins Subject: Re: [PATCH] Migration cache In-Reply-To: <20041021103005.GA18917@logos.cnet> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: Hirokazu Takahashi , haveblue@us.ibm.com, iwamoto@valinux.co.jp, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org List-ID: On Thu, 21 Oct 2004, Marcelo Tosatti wrote: > On Thu, Oct 21, 2004 at 02:10:44AM +0900, Hirokazu Takahashi wrote: > > > > I guess it would be better to reserve one swap type for the migration > > cache instead of reserving the bit to reduce the impact of the maximum > > number of swap types. I thought the same ... > By reserving one swap type we would also use a bit. Using a swap type is > the same thing as using a bit in the swap pagetableentry. (the swap type > has 5 bits reserved for swap devices, 2^5 = 32 swap devices). ... and don't understand your response. Reserving a swap type leaves 31 swap devices for normal use, okay; but reserving a bit leaves only 16 swap devices for normal use. Hugh -- 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