summaryrefslogtreecommitdiffstats
path: root/fs/ceph/caps.c
diff options
context:
space:
mode:
authorChengguang Xu <cgxu519@icloud.com>2018-02-24 18:35:29 +0800
committerIlya Dryomov <idryomov@gmail.com>2018-04-02 10:12:46 +0200
commite327ce068518e38c0182739e879b9dce477c8d85 (patch)
treea727fff9856f7a0a6497c1425372056498cd4fc5 /fs/ceph/caps.c
parentb884014a91a49ed0e7198d276b28887cc48363bd (diff)
downloadlinux-e327ce068518e38c0182739e879b9dce477c8d85.tar.bz2
ceph: optimizing cap allocation
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@icloud.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/caps.c')
-rw-r--r--fs/ceph/caps.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 1d02648788e3..421cdce71fb0 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -285,7 +285,23 @@ struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,
mdsc->caps_use_count++;
mdsc->caps_total_count++;
spin_unlock(&mdsc->caps_list_lock);
+ } else {
+ 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);
}
+
return cap;
}