crush: add chooseleaf_stable tunable

Add a tunable to fix the bug that chooseleaf may cause unnecessary pg
migrations when some device fails.

Reflects ceph.git commit fdb3f664448e80d984470f32f04e2e6f03ab52ec.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
This commit is contained in:
Ilya Dryomov
2016-01-31 14:36:07 +01:00
parent 56a4f3091d
commit dc6ae6d8e7
2 changed files with 21 additions and 5 deletions

View File

@@ -59,7 +59,8 @@ enum {
CRUSH_RULE_SET_CHOOSELEAF_TRIES = 9, /* override chooseleaf_descend_once */
CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES = 10,
CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES = 11,
CRUSH_RULE_SET_CHOOSELEAF_VARY_R = 12
CRUSH_RULE_SET_CHOOSELEAF_VARY_R = 12,
CRUSH_RULE_SET_CHOOSELEAF_STABLE = 13
};
/*
@@ -205,6 +206,11 @@ struct crush_map {
* mappings line up a bit better with previous mappings. */
__u8 chooseleaf_vary_r;
/* if true, it makes chooseleaf firstn to return stable results (if
* no local retry) so that data migrations would be optimal when some
* device fails. */
__u8 chooseleaf_stable;
#ifndef __KERNEL__
/*
* version 0 (original) of straw_calc has various flaws. version 1