[PATCH AUTOSEL 5.1 007/375] IB/hfi1: Fix WQ_MEM_RECLAIM warning

Sasha Levin
2019-05-22T20:04:37Z

From: Mike Marciniszyn <mike.marciniszyn@intel.com>

[ Upstream commit 4c4b1996b5db688e2dcb8242b0a3bf7b1e845e42 ]

The work_item cancels that occur when a QP is destroyed can elicit the
following trace:

workqueue: WQ_MEM_RECLAIM ipoib_wq:ipoib_cm_tx_reap [ib_ipoib] is flushing !WQ_MEM_RECLAIM hfi0_0:_hfi1_do_send [hfi1]
WARNING: CPU: 7 PID: 1403 at kernel/workqueue.c:2486 check_flush_dependency+0xb1/0x100
Call Trace:
__flush_work.isra.29+0x8c/0x1a0
? __switch_to_asm+0x40/0x70
__cancel_work_timer+0x103/0x190
? schedule+0x32/0x80
iowait_cancel_work+0x15/0x30 [hfi1]
rvt_reset_qp+0x1f8/0x3e0 [rdmavt]
rvt_destroy_qp+0x65/0x1f0 [rdmavt]
? _cond_resched+0x15/0x30
ib_destroy_qp+0xe9/0x230 [ib_core]
ipoib_cm_tx_reap+0x21c/0x560 [ib_ipoib]
process_one_work+0x171/0x370
worker_thread+0x49/0x3f0
kthread+0xf8/0x130
? max_active_store+0x80/0x80
? kthread_bind+0x10/0x10
ret_from_fork+0x35/0x40

Since QP destruction frees memory, hfi1_wq should have the WQ_MEM_RECLAIM.

The hfi1_wq does not allocate memory with GFP_KERNEL or otherwise become
entangled with memory reclaim, so this flag is appropriate.

Fixes: 0a226edd203f ("staging/rdma/hfi1: Use parallel workqueue for SDMA engines")
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/hfi1/init.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index faaaac8fbc553..3af5eb10a5ffb 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -805,7 +805,8 @@ static int create_workqueues(struct hfi1_devdata *dd)
ppd->hfi1_wq =
alloc_workqueue(
"hfi%d_%d",
- WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
+ WQ_SYSFS | WQ_HIGHPRI | WQ_CPU_INTENSIVE |
+ WQ_MEM_RECLAIM,
HFI1_MAX_ACTIVE_WORKQUEUE_ENTRIES,
dd->unit, pidx);
if (!ppd->hfi1_wq)
--
2.20.1