With the addition of erasure coding support in the future, scratch variable-length array in crush_do_rule_ary() is going to grow to at least 200 bytes on average, on top of another 128 bytes consumed by rawosd/osd arrays in the call chain. Replace it with a buffer inside struct osdmap and a mutex. This shouldn't result in any contention, because all osd requests were already serialized by request_mutex at that point; the only unlocked caller was ceph_ioctl_get_dataloc().
Signed-off-by: Ilya Dryomov <[email protected]> --- include/linux/ceph/osdmap.h | 3 +++ net/ceph/osdmap.c | 25 ++++++++++++++++--------- 2 files changed, 19 insertions(+), 9 deletions(-) diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h index 49ff69f0746b..8c8b3cefc28b 100644 --- a/include/linux/ceph/osdmap.h +++ b/include/linux/ceph/osdmap.h @@ -84,6 +84,9 @@ struct ceph_osdmap { /* the CRUSH map specifies the mapping of placement groups to * the list of osds that store+replicate them. */ struct crush_map *crush; + + struct mutex crush_scratch_mutex; + int crush_scratch_ary[CEPH_PG_MAX_SIZE * 3]; }; static inline void ceph_oid_set_name(struct ceph_object_id *oid, diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index aade4a5c1c07..9d1aaa24def6 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -698,7 +698,9 @@ struct ceph_osdmap *osdmap_decode(void **p, void *end) map = kzalloc(sizeof(*map), GFP_NOFS); if (map == NULL) return ERR_PTR(-ENOMEM); + map->pg_temp = RB_ROOT; + mutex_init(&map->crush_scratch_mutex); ceph_decode_16_safe(p, end, version, bad); if (version > 6) { @@ -1142,14 +1144,20 @@ int ceph_oloc_oid_to_pg(struct ceph_osdmap *osdmap, } EXPORT_SYMBOL(ceph_oloc_oid_to_pg); -static int crush_do_rule_ary(const struct crush_map *map, int ruleno, int x, - int *result, int result_max, - const __u32 *weight, int weight_max) +static int do_crush(struct ceph_osdmap *map, int ruleno, int x, + int *result, int result_max, + const __u32 *weight, int weight_max) { - int scratch[result_max * 3]; + int r; + + BUG_ON(result_max > CEPH_PG_MAX_SIZE); + + mutex_lock(&map->crush_scratch_mutex); + r = crush_do_rule(map->crush, ruleno, x, result, result_max, + weight, weight_max, map->crush_scratch_ary); + mutex_unlock(&map->crush_scratch_mutex); - return crush_do_rule(map, ruleno, x, result, result_max, - weight, weight_max, scratch); + return r; } /* @@ -1205,9 +1213,8 @@ static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid, pool->pgp_num_mask) + (unsigned)pgid.pool; } - r = crush_do_rule_ary(osdmap->crush, ruleno, pps, - osds, min_t(int, pool->size, *num), - osdmap->osd_weight, osdmap->max_osd); + r = do_crush(osdmap, ruleno, pps, osds, min_t(int, pool->size, *num), + osdmap->osd_weight, osdmap->max_osd); if (r < 0) { pr_err("error %d from crush rule: pool %lld ruleset %d type %d" " size %d\n", r, pgid.pool, pool->crush_ruleset, -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
