Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751424AbaLBIks (ORCPT ); Tue, 2 Dec 2014 03:40:48 -0500 Received: from mail.windriver.com ([147.11.1.11]:63497 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750991AbaLBIkr (ORCPT ); Tue, 2 Dec 2014 03:40:47 -0500 Message-ID: <547D7B05.50406@windriver.com> Date: Tue, 2 Dec 2014 16:40:37 +0800 From: zhangxiao User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: NeilBrown CC: , , Subject: Re: The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible? References: <547D790E.3070803@windriver.com> <20141202193618.6d3adb22@notabene.brown> In-Reply-To: <20141202193618.6d3adb22@notabene.brown> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [128.224.163.132] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014年12月02日 16:36, NeilBrown wrote: > On Tue, 2 Dec 2014 16:32:14 +0800 zhangxiao wrote: > >> Hi NeilBrown, >> >> See drivers/md/dm-bufio.c as below: >> 50 /* >> 51 * Buffer hash >> 52 */ >> 53 #define DM_BUFIO_HASH_BITS 20 >> 54 #define DM_BUFIO_HASH(block) \ >> 55 ((((block) >> DM_BUFIO_HASH_BITS) ^ (block)) & \ >> 56 ((1 << DM_BUFIO_HASH_BITS) - 1)) >> "drivers/md/dm-bufio.c" 1854L, 45375C >> >> >> DM_BUFIO_HASH_BITS was defined as 20 and it maybe not fit for some >> use case with limited resources. Do we have any plan to make it more >> flexible? Like module parameter or something else? >> > > Thanks, but this question should be address to: > Thank you for your kindly remind. :-) Regards Xiao > DEVICE-MAPPER (LVM) > M: Alasdair Kergon > M: Mike Snitzer > M: dm-devel@redhat.com > L: dm-devel@redhat.com > W: http://sources.redhat.com/dm > Q: http://patchwork.kernel.org/project/dm-devel/list/ > T: git git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git > T: quilt http://people.redhat.com/agk/patches/linux/editing/ > S: Maintained > F: Documentation/device-mapper/ > F: drivers/md/dm* > F: drivers/md/persistent-data/ > F: include/linux/device-mapper.h > F: include/linux/dm-*.h > F: include/uapi/linux/dm-*.h > > NeilBrown > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/