In order to reduce the contention on CQ locking (present
in some LLDDs) we poll in batches of 16 work completion items.
Signed-off-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
drivers/infiniband/ulp/isert/ib_isert.c | 12 +++++++-----
drivers/infiniband/ulp/isert/ib_isert.h | 2 ++
2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 2284148..276054b 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2047,13 +2047,15 @@ isert_cq_work(struct work_struct *work)
enum { isert_poll_budget = 65536 };
struct isert_comp *comp = container_of(work, struct isert_comp,
work);
- int completed = 0;
- struct ib_wc wc;
+ struct ib_wc *const wcs = comp->wcs;
+ int i, n, completed = 0;
- while (ib_poll_cq(comp->cq, 1, &wc) == 1) {
- isert_handle_wc(&wc);
+ while ((n = ib_poll_cq(comp->cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
+ for (i = 0; i < n; i++)
+ isert_handle_wc(&wcs[i]);
- if (++completed >= isert_poll_budget)
+ completed += n;
+ if (completed >= isert_poll_budget)
break;
}
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index fc1d323..2a0721f 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -165,6 +165,7 @@ struct isert_conn {
*
* @device: pointer to device handle
* @cq: completion queue
+ * @wcs: work completion array
* @active_qps: Number of active QPs attached
* to completion context
* @work: completion work handle
@@ -172,6 +173,7 @@ struct isert_conn {
struct isert_comp {
struct isert_device *device;
struct ib_cq *cq;
+ struct ib_wc wcs[16];
int active_qps;
struct work_struct work;
};
--
1.7.1
--
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