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 <ilya.dryomov@xxxxxxxxxxx>
---
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
--
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