On Tue, Sep 09, 2025 at 04:48:19PM +0200, Philipp Reisner wrote: > On Mon, Sep 8, 2025 at 4:25 PM Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > > On Fri, Aug 22, 2025 at 10:19:41AM +0200, Philipp Reisner wrote: > > > 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. > > > > Can you please be more specific about the deadlock? > > Please write call stack to describe it. > > > Instead of a call stack, I write it from top to bottom: > > The line numbers in the .c files are valid for Linux-6.16: > > 1 rxe_cq_post() [rxe_cq.c:85] > 2 spin_lock_irqsave() [rxe_cq.c:93] > 3 cq->ibcq.comp_handler() [rxe_cq.c:116] > 4 some_comp_handler() > 5 ib_poll_cq() > 6 cq->device->ops.poll_cq() [ib_verbs.h:4037] > 7 rxe_poll_cq() [rxe_verbs.c:1165] > 8 spin_lock_irqsave() [rxe_verbs.c:1172] > > In line 8 of this call graph, it deadlocks because the spinlock > was already acquired in line 2 of the call graph. Is this even legal in verbs? I'm not sure you can do pull cq from a interrupt driven comp handler.. Is something already doing this intree? Jason
