alloc_workqueue replaces deprecated create_workqueue().
kfd_process_wq is used for delay destruction. A work item embedded in kfd_process gets queued to kfd_process_wq and when it executes it destroys and frees the containing kfd_process and thus itself. This requires a dedicated workqueue because a work item once queued, may get freed at any point of time and any external entity cannot flush the work item. So, in order to wait for such a work item, it needs to be put on a dedicated workqueue. kfd_module_exit() calls kfd_process_destroy_wq which ensures that all pending work items are finished before the module is removed. flush_workqueue is unnecessary since destroy_workqueue() itself calls drain_workqueue() which flushes repeatedly till the workqueue becomes empty. Hence flush_workqueue has been removed. Signed-off-by: Bhaktipriya Shridhar <[hidden email]> --- drivers/gpu/drm/amd/amdkfd/kfd_process.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c index ac00579..b21d3fc8 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c @@ -63,13 +63,12 @@ static struct kfd_process *create_process(const struct task_struct *thread); void kfd_process_create_wq(void) { if (!kfd_process_wq) - kfd_process_wq = create_workqueue("kfd_process_wq"); + kfd_process_wq = alloc_workqueue("kfd_process_wq",0,0); } void kfd_process_destroy_wq(void) { if (kfd_process_wq) { - flush_workqueue(kfd_process_wq); destroy_workqueue(kfd_process_wq); kfd_process_wq = NULL; } -- 2.1.4 |
On Fri, May 27, 2016 at 12:15:17AM +0530, Bhaktipriya Shridhar wrote:
> alloc_workqueue replaces deprecated create_workqueue(). > > kfd_process_wq is used for delay destruction. A work item embedded in > kfd_process gets queued to kfd_process_wq and when it executes it > destroys and frees the containing kfd_process and thus itself. > > This requires a dedicated workqueue because a work item once queued, may > get freed at any point of time and any external entity cannot > flush the work item. So, in order to wait for such a work item, > it needs to be put on a dedicated workqueue. > > kfd_module_exit() calls kfd_process_destroy_wq which ensures that all > pending work items are finished before the module is removed. > > flush_workqueue is unnecessary since destroy_workqueue() itself calls > drain_workqueue() which flushes repeatedly till the workqueue becomes empty. > > Hence flush_workqueue has been removed. create_workqueue(NAME) maps to alloc_workqueue(NAME, WQ_MEM_RECLAIM, 1), so the change is effectively dropping WQ_MEM_RECLAIM and changing concurrency value from 1 to WQ_DFL_ACTIVE. It'd be nice to explain why these changes are safe and I think they're. It just needs explanations. > Signed-off-by: Bhaktipriya Shridhar <[hidden email]> Other than that, Acked-by: Tejun Heo <[hidden email]> Thanks. -- tejun |
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