[PATCH 1/3] drm/amdkfd: Replace cpu_relax() with schedule() in DQM

Oded Gabbay oded.gabbay at amd.com
Thu Jan 15 02:46:25 PST 2015


In order not to occupy the current core and thus prevent the core from
servicing IOMMU PPR requests, this patch replaces the call in DQM to
cpu_relax() with a call to schedule().

Signed-off-by: Oded Gabbay <oded.gabbay at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 102aaba..08cf5b3 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -26,6 +26,7 @@
 #include <linux/types.h>
 #include <linux/printk.h>
 #include <linux/bitops.h>
+#include <linux/sched.h>
 #include "kfd_priv.h"
 #include "kfd_device_queue_manager.h"
 #include "kfd_mqd_manager.h"
@@ -827,7 +828,7 @@ static int fence_wait_timeout(unsigned int *fence_addr,
 			pr_err("kfd: qcm fence wait loop timeout expired\n");
 			return -ETIME;
 		}
-		cpu_relax();
+		schedule();
 	}
 
 	return 0;
-- 
2.1.0



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