diff options
| author |   Mike Marciniszyn <mike.marciniszyn@intel.com> | 2019-06-14 12:32:26 -0400 |
|---|---|---|
| committer |   Doug Ledford <dledford@redhat.com> | 2019-06-17 21:15:40 -0400 |
| commit | cf131a81967583ae737df6383a0893b9fee75b4e (patch) | |
| tree | 8ebb349f62700de5878a2919070031878de90f50 /drivers/infiniband/hw/hfi1 | |
| parent | IB/hfi1: Correct tid qp rcd to match verbs context (diff) | |
| download | linux-dev-cf131a81967583ae737df6383a0893b9fee75b4e.tar.xz linux-dev-cf131a81967583ae737df6383a0893b9fee75b4e.zip | |
IB/hfi1: Avoid hardlockup with flushlist_lock
Heavy contention of the sde flushlist_lock can cause hard lockups at
extreme scale when the flushing logic is under stress.
Mitigate by replacing the item at a time copy to the local list with
an O(1) list_splice_init() and using the high priority work queue to
do the flushes.
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Cc: <stable@vger.kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/hw/hfi1')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/sdma.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index b0110728f541..70828de7436b 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -410,10 +410,7 @@ static void sdma_flush(struct sdma_engine *sde) sdma_flush_descq(sde); spin_lock_irqsave(&sde->flushlist_lock, flags); /* copy flush list */ - list_for_each_entry_safe(txp, txp_next, &sde->flushlist, list) { - list_del_init(&txp->list); - list_add_tail(&txp->list, &flushlist); - } + list_splice_init(&sde->flushlist, &flushlist); spin_unlock_irqrestore(&sde->flushlist_lock, flags); /* flush from flush list */ list_for_each_entry_safe(txp, txp_next, &flushlist, list) @@ -2413,7 +2410,7 @@ unlock_noconn: list_add_tail(&tx->list, &sde->flushlist); spin_unlock(&sde->flushlist_lock); iowait_inc_wait_count(wait, tx->num_desc); - schedule_work(&sde->flush_worker); + queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker); ret = -ECOMM; goto unlock; nodesc: @@ -2511,7 +2508,7 @@ unlock_noconn: iowait_inc_wait_count(wait, tx->num_desc); } spin_unlock(&sde->flushlist_lock); - schedule_work(&sde->flush_worker); + queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker); ret = -ECOMM; goto update_tail; nodesc: |