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authorAndrew Boyer <andrew.boyer@dell.com>2016-11-23 18:39:22 +0100
committerDoug Ledford <dledford@redhat.com>2016-12-12 22:31:45 +0100
commitaccacb8f51c299965939ac56926d1c718e2691a1 (patch)
tree86e7ef63e3dfb70f5702c33a48ef721b7deb1e2a /drivers/infiniband
parentIB/rxe: Add support for zero-byte operations (diff)
downloadlinux-accacb8f51c299965939ac56926d1c718e2691a1.tar.xz
linux-accacb8f51c299965939ac56926d1c718e2691a1.zip
IB/rxe: Add support for IB_CQ_REPORT_MISSED_EVENTS
Peek at the CQ after arming it so that we can return a hint. This avoids missed completions due to a race between posting CQEs and arming the CQ. For example, CM teardown waits on MAD requests to complete with ib_cq_poll_work(). Without this fix, the last completion might be left on the CQ, hanging the kthread doing the teardown. The console backtraces look like this: [ 4199.911284] Call Trace: [ 4199.911401] [<ffffffff9657fe95>] schedule+0x35/0x80 [ 4199.911556] [<ffffffff965830df>] schedule_timeout+0x22f/0x2c0 [ 4199.911727] [<ffffffff9657f7a8>] ? __schedule+0x368/0xa20 [ 4199.911891] [<ffffffff96580903>] wait_for_completion+0xb3/0x130 [ 4199.912067] [<ffffffff960a17e0>] ? wake_up_q+0x70/0x70 [ 4199.912243] [<ffffffffc074a06d>] cm_destroy_id+0x13d/0x450 [ib_cm] [ 4199.912422] [<ffffffff961615d5>] ? printk+0x57/0x73 [ 4199.912578] [<ffffffffc074a390>] ib_destroy_cm_id+0x10/0x20 [ib_cm] [ 4199.912759] [<ffffffffc076098c>] rdma_destroy_id+0xac/0x340 [rdma_cm] [ 4199.912941] [<ffffffffc076f2cc>] 0xffffffffc076f2cc Signed-off-by: Andrew Boyer <andrew.boyer@dell.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/sw/rxe/rxe_verbs.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 19841c863daf..de39b0a081de 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -1007,11 +1007,19 @@ static int rxe_peek_cq(struct ib_cq *ibcq, int wc_cnt)
static int rxe_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
{
struct rxe_cq *cq = to_rcq(ibcq);
+ unsigned long irq_flags;
+ int ret = 0;
+ spin_lock_irqsave(&cq->cq_lock, irq_flags);
if (cq->notify != IB_CQ_NEXT_COMP)
cq->notify = flags & IB_CQ_SOLICITED_MASK;
- return 0;
+ if ((flags & IB_CQ_REPORT_MISSED_EVENTS) && !queue_empty(cq->queue))
+ ret = 1;
+
+ spin_unlock_irqrestore(&cq->cq_lock, irq_flags);
+
+ return ret;
}
static struct ib_mr *rxe_get_dma_mr(struct ib_pd *ibpd, int access)