On Wed, Dec 03 2014 at 9:19am -0500, Joe Thornber <thornber@xxxxxxxxxx> wrote: > On Tue, Dec 02, 2014 at 09:00:17AM -0500, Mike Snitzer wrote: > > On Tue, Dec 02 2014 at 3:43am -0500, > > zhangxiao <xiao.zhang@xxxxxxxxxxxxx> wrote: > > > > > 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? > > > > No immediate plans. > > That hash table has been replaced with a red/black tree. > > https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-for-3.19&id=4e420c452b11edf9d510c8180ac66f529e5b6206 Ah yes, you'd think I'd have remembered that change. Thanks for keeping me honest Joe! -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
