From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhangxiao Subject: The DM_BUFIO_HASH_BITS is defined as 20, any plan to make it flexible? Date: Tue, 2 Dec 2014 16:43:50 +0800 Message-ID: <547D7BC6.6070708@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: agk@redhat.com, snitzer@redhat.com, linux-kernel@vger.kernel.org, NeilBrown , linux-raid@vger.kernel.org, dm-devel@redhat.com List-Id: linux-raid.ids Hi Experts, 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 Xiao