In case the CQ is packed with completions, we can't just
hog the CPU forever. Poll until a sufficient budget (currently
hard-coded to 64k completions) and if budget is exhausted, bailout
and give a chance to other threads.
Signed-off-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
drivers/infiniband/ulp/isert/ib_isert.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 603d6b8..46ba758 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2044,13 +2044,19 @@ isert_handle_wc(struct ib_wc *wc)
static void
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;
- while (ib_poll_cq(comp->cq, 1, &wc) == 1)
+ while (ib_poll_cq(comp->cq, 1, &wc) == 1) {
isert_handle_wc(&wc);
+ if (++completed >= isert_poll_budget)
+ break;
+ }
+
ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP);
}
--
1.7.1
--
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