When setting high volume of caps_min_count or having many
unreserved caps, unused caps may always keep in the ->caps_list
even can't get new cap from kmem_cache_alloc because lack of
maximum limitation of caps_avail_count. Hence reuse caps in
->caps_list if available, it's maybe better than setting max
limitation of caps_avail_count and releasing unused caps when
reaching the limit.
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxx>
---
Only compile tested.
fs/ceph/caps.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6582c45..b598a24 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -280,6 +280,23 @@ struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,
/* temporary, until we do something about cap import/export */
if (!ctx) {
cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
+ if (!cap) {
+ spin_lock(&mdsc->caps_list_lock);
+ if (mdsc->caps_avail_count) {
+ BUG_ON(list_empty(&mdsc->caps_list));
+
+ mdsc->caps_avail_count--;
+ mdsc->caps_use_count++;
+ cap = list_first_entry(&mdsc->caps_list,
+ struct ceph_cap, caps_item);
+ list_del(&cap->caps_item);
+
+ BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+ mdsc->caps_reserve_count + mdsc->caps_avail_count);
+ }
+ spin_unlock(&mdsc->caps_list_lock);
+ }
+
if (cap) {
spin_lock(&mdsc->caps_list_lock);
mdsc->caps_use_count++;
--
1.8.3.1
--
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