在 2025/8/19 10:24, Philipp Reisner 写道:
Allow the comp_handler callback implementation to call ib_poll_cq().
A call to ib_poll_cq() calls rxe_poll_cq() with the rdma_rxe driver.
And rxe_poll_cq() locks cq->cq_lock. That leads to a spinlock deadlock.
The Mellanox and Intel drivers allow a comp_handler callback
implementation to call ib_poll_cq().
Avoid the deadlock by calling the comp_handler callback without
holding cq->cq_lock.
Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
---
The new patch should be sent in a new mail thread; it is not appropriate
to reply to the old thread.
Additionally:
The subject line does not include a version number.
The commit log of the new patch does not contain a changelog.
Other than these issues, I am fine with this commit.
Reviewed-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxx>
Zhu Yanjun
drivers/infiniband/sw/rxe/rxe_cq.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_cq.c b/drivers/infiniband/sw/rxe/rxe_cq.c
index fffd144d509e..95652001665d 100644
--- a/drivers/infiniband/sw/rxe/rxe_cq.c
+++ b/drivers/infiniband/sw/rxe/rxe_cq.c
@@ -88,6 +88,7 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited)
int full;
void *addr;
unsigned long flags;
+ bool invoke_handler = false;
spin_lock_irqsave(&cq->cq_lock, flags);
@@ -113,11 +114,14 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited)
if ((cq->notify & IB_CQ_NEXT_COMP) ||
(cq->notify & IB_CQ_SOLICITED && solicited)) {
cq->notify = 0;
- cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
+ invoke_handler = true;
}
spin_unlock_irqrestore(&cq->cq_lock, flags);
+ if (invoke_handler)
+ cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
+
return 0;
}
