Hi Christophe, OK, thanks a lot. Regards, Yang --- On 2017/6/21 18:22, Christophe Varoqui wrote: > This version is now merged. > Thanks. > > Incremental enhancements can go from there if needed. > > On Wed, Jun 21, 2017 at 11:40 AM, Yang Feng <philip.yang@xxxxxxxxxx <mailto:philip.yang@xxxxxxxxxx>> wrote: > > libmultipath/prioritizers: Prioritizer for device mapper multipath, > where the corresponding priority values of specific paths are provided > by a latency algorithm on the logarithmic scale. And the latency algorithm > is dependent on the following arguments(io_num and base_num). > The principle of the algorithm is illustrated as follows: > 1. By sending a certain number "io_num" of read IOs to the current > path continuously, the IOs' average latency can be calculated. > 2. Max average latency value is 100s, and min value is 1us. According > to the average latency of each path and the "base_number" of logarithmic > scale, the priority "rc" of each path can be provided. > > For example: If base_num=10, the paths will be grouped in priority groups > with path latency <=1us, (1us, 10us], (10us, 100us], (100us, 1ms], (1ms, 10ms], > (10ms, 100ms], (100ms, 1s], (1s, 10s], (10s, 100s], >100s. As follows: > > <=1us (1us, 10us] (10us, 100us] >100s > |------------------|------------------|------------------|...|------------------| > | priority rank 9 | priority rank 8 | priority rank 7 |...| priority rank 0 | > |------------------|------------------|------------------|...|------------------| > Priority Rank Partitioning > > Signed-off-by: Yang Feng <philip.yang@xxxxxxxxxx <mailto:philip.yang@xxxxxxxxxx>> > Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx <mailto:bmarzins@xxxxxxxxxx>> > Reviewed-by: Martin Wilck <mwilck@xxxxxxxx <mailto:mwilck@xxxxxxxx>> > Reviewed-by: Xose Vazquez Perez <xose.vazquez@xxxxxxxxx <mailto:xose.vazquez@xxxxxxxxx>> > Reviewed-by: Hannes Reinecke <hare@xxxxxxx <mailto:hare@xxxxxxx>> > --- > libmultipath/prio.h | 1 + > libmultipath/prioritizers/Makefile | 4 + > libmultipath/prioritizers/path_latency.c | 257 +++++++++++++++++++++++++++++++ > multipath/multipath.conf.5 | 20 +++ > 4 files changed, 282 insertions(+) > create mode 100644 libmultipath/prioritizers/path_latency.c > --- -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
