On 2019/11/26 20:24, Yan, Zheng wrote:
On Tue, Nov 26, 2019 at 7:25 PM Xiubo Li <xiubli@xxxxxxxxxx> wrote:
On 2019/11/26 19:03, Yan, Zheng wrote:
On 11/26/19 6:01 PM, Xiubo Li wrote:
On 2019/11/26 17:49, Yan, Zheng wrote:
On Tue, Nov 26, 2019 at 4:57 PM <xiubli@xxxxxxxxxx> wrote:
From: Xiubo Li <xiubli@xxxxxxxxxx>
The nr in ceph_reclaim_caps_nr() is very possibly larger than 1,
so we may miss it and the reclaim work couldn't triggered as expected.
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
fs/ceph/mds_client.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 08b70b5ee05e..547ffe16f91c 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2020,7 +2020,7 @@ void ceph_reclaim_caps_nr(struct
ceph_mds_client *mdsc, int nr)
if (!nr)
return;
val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
- if (!(val % CEPH_CAPS_PER_RELEASE)) {
+ if (val / CEPH_CAPS_PER_RELEASE) {
atomic_set(&mdsc->cap_reclaim_pending, 0);
ceph_queue_cap_reclaim_work(mdsc);
}
this will call ceph_queue_cap_reclaim_work too frequently
No it won't, the '/' here equals to '>=' and then the
"mdsc->cap_reclaim_pending" will be reset and it will increase from 0
again.
It will make sure that only when "mdsc->cap_reclaim_pending >=
CEPH_CAPS_PER_RELEASE" will call the work queue.
Work does not get executed immediately. call
ceph_queue_cap_reclaim_work() when val == CEPH_CAPS_PER_RELEASE is
enough. There is no point to call it too frequently
Yeah, it true and I am okay with this. Just going through the session
release related code, and saw the "nr" parameter will be "ctx->used" in
ceph_reclaim_caps_nr(mdsc, ctx->used), and in case there has many
sessions with tremendous amount of caps. In corner case that we may
always miss the condition that the "val == CEPH_CAPS_PER_RELEASE" here.
good catch. But the test should be something like
"if ((val % CEPH_CAPS_PER_RELEASE) < nr)"
Sure, this looks a bit more graceful.
Will fix it.
Thanks Yan
BRs
IMO, it wants to fire the work queue once "val >=
CEPH_CAPS_PER_RELEASE", but it is not working like this, the val may
just skip it without doing any thing.
Thanks
--
2.21.0
