[PATCH] qlge: Replace create_singlethread_workqueue with alloc_ordered_workqueue

[PATCH] qlge: Replace create_singlethread_workqueue with alloc_ordered_workqueue

[Amitoj Kaur Chawla]

Replace deprecated create_singlethread_workqueue with
alloc_ordered_workqueue.

Use alloc_ordered_workqueue for work like getting tx/rx frame sizes,
resetting MPI processor,setting asic recovery bit as only one work
item should be in queue/executing at any given time.

WQ_MEM_RECLAIM flag has been set to ensure execution context
regardless of memory pressure since qdev->workqueue might be used in
memory reclaim path.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
---
 drivers/net/ethernet/qlogic/qlge/qlge_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_main.c b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
index 9979764..089a9cb 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge_main.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
@@ -4676,7 +4676,7 @@ static int ql_init_device(struct pci_dev *pdev, struct net_device *ndev,
 	/*
 	 * Set up the operating parameters.
 	 */
-	qdev->workqueue = create_singlethread_workqueue(ndev->name);
+	qdev->workqueue = alloc_ordered_workqueue(ndev->name, WQ_MEM_RECLAIM);
 	INIT_DELAYED_WORK(&qdev->asic_reset_work, ql_asic_reset_work);
 	INIT_DELAYED_WORK(&qdev->mpi_reset_work, ql_mpi_reset_work);
 	INIT_DELAYED_WORK(&qdev->mpi_work, ql_mpi_work);
-- 
1.9.1

Re: [Outreachy kernel] [PATCH] qlge: Replace create_singlethread_workqueue with alloc_ordered_workqueue

[Tejun Heo]

Hello,

On Tue, Mar 15, 2016 at 08:08:52PM +0530, Amitoj Kaur Chawla wrote:
> Replace deprecated create_singlethread_workqueue with
> alloc_ordered_workqueue.
> 
> Use alloc_ordered_workqueue for work like getting tx/rx frame sizes,
> resetting MPI processor,setting asic recovery bit as only one work
> item should be in queue/executing at any given time.

It'd be nice to explain why that is the case.  It's okay to be
speculative and ask the maintainers - e.g. say "Because of XXX and
YYY, the ordering seems necessary" and then in the section below "---"
ask the maintainer whether the assumption is correct.

> WQ_MEM_RECLAIM flag has been set to ensure execution context
> regardless of memory pressure since qdev->workqueue might be used in
> memory reclaim path.

Hmmm... why?  Network devices don't usually sit in the memory reclaim
path although there are nfs and storage-over-net cases.  I don't think
we have a clear rule here.  I'll ask around, but for now, I think it'd
be better to default to not set it.

Thanks.

-- 
tejun