From: Oded Gabbay <oded.gabbay@amd.com>
To: dri-devel@lists.freedesktop.org
Subject: [PATCH 10/12] amdkfd: use schedule() in sync_with_hw
Date: Fri, 21 Nov 2014 10:51:58 +0200 [thread overview]
Message-ID: <1416559920-7779-1-git-send-email-oded.gabbay@amd.com> (raw)
In-Reply-To: <1416559111-5900-1-git-send-email-oded.gabbay@amd.com>
amdkfd uses cpu_relax() in its sync_with_hw() function. Because cpu_relax() is
defined as 'REP; NOP' on x86_64, it will block the CPU from servicing
IOMMU PPR requests.
This may cause a deadlock, because sync_with_hw() won't be completed
until the PPR request has been served.
Therefore, we need to use schedule() instead of cpu_relax() as it is the
minimum requirement to allow other threads to execute.
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c b/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
index 5055fc9..9abac48 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
@@ -25,6 +25,7 @@
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/printk.h>
+#include <linux/sched.h>
#include "kfd_kernel_queue.h"
#include "kfd_priv.h"
#include "kfd_device_queue_manager.h"
@@ -274,7 +275,7 @@ static int sync_with_hw(struct kernel_queue *kq, unsigned long timeout_ms)
*kq->wptr_kernel, *kq->rptr_kernel);
return -ETIME;
}
- cpu_relax();
+ schedule();
}
return 0;
--
2.1.0
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next prev parent reply other threads:[~2014-11-21 8:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-21 8:38 [PATCH 00/12] amdkfd fixes (sparse and some more) Oded Gabbay
2014-11-21 8:43 ` [PATCH 01/12] amdkfd: Fix sparse warnings in kfd_chardev.c Oded Gabbay
2014-11-21 8:43 ` [PATCH 02/12] amdkfd: Fix sparse warnings in kfd_topology.c Oded Gabbay
2014-11-21 8:47 ` [PATCH 03/12] amdkfd: test_kq() can be static Oded Gabbay
2014-11-21 8:47 ` [PATCH 04/12] amdkfd: pqm_get_kernel_queue() " Oded Gabbay
2014-11-21 8:47 ` [PATCH 05/12] amdkfd: Fix sparse warnings in kfd_flat_memory.c Oded Gabbay
2014-11-21 8:47 ` [PATCH 06/12] amdkfd: is_occupied() can be static Oded Gabbay
2014-11-21 8:47 ` [PATCH 07/12] amdkfd: fence_wait_timeout() " Oded Gabbay
2014-11-21 8:47 ` [PATCH 08/12] amdkfd: add __iomem attribute to doorbell_ptr Oded Gabbay
2014-11-21 8:49 ` [PATCH 09/12] amdkfd: Fix memory leak on process deregistration Oded Gabbay
2014-11-21 8:51 ` Oded Gabbay [this message]
2014-11-21 8:51 ` [PATCH 11/12] amdkfd: Instead of using get function, use container_of Oded Gabbay
2014-11-21 8:52 ` [PATCH 12/12] amdkfd: Clear ctx cb before suspend Oded Gabbay
2014-11-21 15:06 ` [PATCH 00/12] amdkfd fixes (sparse and some more) Alex Deucher
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