diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2026-05-06 11:26:50 -0400 |
|---|---|---|
| committer | Chuck Lever <cel@kernel.org> | 2026-06-09 16:32:59 -0400 |
| commit | 9545262f7e58d67de413d5a47ea2a3f2e59ba9f6 (patch) | |
| tree | 11b8f80ee664ce4d9bd9c222bd36c0558bc8a1e1 /include | |
| parent | 2804a16b9e51f803a32ac2e9a014f5851a7cc3f4 (diff) | |
svcrdma: Release write chunk resources without re-queuing
Each RDMA Send completion triggers a cascade of work items on the
svcrdma_wq unbound workqueue:
ib_cq_poll_work (on ib_comp_wq, per-CPU)
-> svc_rdma_send_ctxt_put -> queue_work [work item 1]
-> svc_rdma_write_info_free -> queue_work [work item 2]
Every transition through queue_work contends on the unbound
pool's spinlock. Profiling an 8KB NFSv3 read/write workload
over RDMA shows about 4% of total CPU cycles spent on this
lock, with the cascading re-queue of write_info release
contributing roughly 1%.
The initial queue_work in svc_rdma_send_ctxt_put is needed to
move release work off the CQ completion context (which runs on
a per-CPU bound workqueue). However, once executing on
svcrdma_wq, there is no need to re-queue for each write_info
structure. svc_rdma_reply_chunk_release already calls
svc_rdma_cc_release inline from the same svcrdma_wq context,
and svc_rdma_recv_ctxt_put does the same from nfsd thread
context.
Release write chunk resources inline in
svc_rdma_write_info_free, removing the intermediate
svc_rdma_write_info_free_async work item and the wi_work
field from struct svc_rdma_write_info.
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Tested-by: Jonathan Flynn <jonathan.flynn@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sunrpc/svc_rdma.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index df6e08aaad57..14eb9d52742e 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -230,7 +230,6 @@ struct svc_rdma_write_info { unsigned int wi_next_off; struct svc_rdma_chunk_ctxt wi_cc; - struct work_struct wi_work; }; struct svc_rdma_send_ctxt { |