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authorZhu Yanjun <yanjunz@mellanox.com>2020-02-12 09:26:33 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-19 19:53:06 +0100
commit2c753af06f23c935e071ba123e380e46537320e0 (patch)
treeb6926d686f0e652cf2f04c99f9f07e7f59f61ea3
parent8662e612ae4c6d9e8065e375152c5e8e2975f936 (diff)
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RDMA/rxe: Fix soft lockup problem due to using tasklets in softirq
commit 8ac0e6641c7ca14833a2a8c6f13d8e0a435e535c upstream. When run stress tests with RXE, the following Call Traces often occur watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [swapper/2:0] ... Call Trace: <IRQ> create_object+0x3f/0x3b0 kmem_cache_alloc_node_trace+0x129/0x2d0 __kmalloc_reserve.isra.52+0x2e/0x80 __alloc_skb+0x83/0x270 rxe_init_packet+0x99/0x150 [rdma_rxe] rxe_requester+0x34e/0x11a0 [rdma_rxe] rxe_do_task+0x85/0xf0 [rdma_rxe] tasklet_action_common.isra.21+0xeb/0x100 __do_softirq+0xd0/0x298 irq_exit+0xc5/0xd0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20 </IRQ> ... The root cause is that tasklet is actually a softirq. In a tasklet handler, another softirq handler is triggered. Usually these softirq handlers run on the same cpu core. So this will cause "soft lockup Bug". Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20200212072635.682689-8-leon@kernel.org Signed-off-by: Zhu Yanjun <yanjunz@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/infiniband/sw/rxe/rxe_comp.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c
index 116cafc9afcf..4bc88708b355 100644
--- a/drivers/infiniband/sw/rxe/rxe_comp.c
+++ b/drivers/infiniband/sw/rxe/rxe_comp.c
@@ -329,7 +329,7 @@ static inline enum comp_state check_ack(struct rxe_qp *qp,
qp->comp.psn = pkt->psn;
if (qp->req.wait_psn) {
qp->req.wait_psn = 0;
- rxe_run_task(&qp->req.task, 1);
+ rxe_run_task(&qp->req.task, 0);
}
}
return COMPST_ERROR_RETRY;
@@ -463,7 +463,7 @@ static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
*/
if (qp->req.wait_fence) {
qp->req.wait_fence = 0;
- rxe_run_task(&qp->req.task, 1);
+ rxe_run_task(&qp->req.task, 0);
}
}
@@ -479,7 +479,7 @@ static inline enum comp_state complete_ack(struct rxe_qp *qp,
if (qp->req.need_rd_atomic) {
qp->comp.timeout_retry = 0;
qp->req.need_rd_atomic = 0;
- rxe_run_task(&qp->req.task, 1);
+ rxe_run_task(&qp->req.task, 0);
}
}
@@ -725,7 +725,7 @@ int rxe_completer(void *arg)
RXE_CNT_COMP_RETRY);
qp->req.need_retry = 1;
qp->comp.started_retry = 1;
- rxe_run_task(&qp->req.task, 1);
+ rxe_run_task(&qp->req.task, 0);
}
if (pkt) {