1 files changed, 34 insertions, 0 deletions
diff --git a/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.14.71/2854-drm-amdkfd-Fix-signal-handling-performance-again.patch b/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.14.71/2854-drm-amdkfd-Fix-signal-handling-performance-again.patch
new file mode 100644
index 00000000..70612718
--- /dev/null
+++ b/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.14.71/2854-drm-amdkfd-Fix-signal-handling-performance-again.patch
@@ -0,0 +1,34 @@
+From dd273e3ccebf830d51d03b55b1b6f110e0ff9fb1 Mon Sep 17 00:00:00 2001
+From: Felix Kuehling <Felix.Kuehling@amd.com>
+Date: Tue, 14 Nov 2017 22:36:36 -0500
+Subject: [PATCH 2854/4131] drm/amdkfd: Fix signal handling performance again
+
+It turns out that idr_for_each_entry is really slow compared to just
+iterating over the slots. Based on measurements the difference is
+estimated to be about a factor 64. That means using idr_for_each_entry
+is only worth it with very few allocated events.
+
+Bug: SWDEV-137662
+
+Change-Id: I1206ad9bf5f8f4437bee49f97c8aab131a2ad201
+Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
+---
+ drivers/gpu/drm/amd/amdkfd/kfd_events.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+index 9bdea43..1c53601 100644
+--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
++++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+@@ -491,7 +491,7 @@ void kfd_signal_event_interrupt(unsigned int pasid, uint32_t partial_id,
+ 			pr_debug_ratelimited("Partial ID invalid: %u (%u valid bits)\n",
+ 					     partial_id, valid_id_bits);
+ 
+-		if (p->signal_event_count < KFD_SIGNAL_EVENT_LIMIT/2) {
++		if (p->signal_event_count < KFD_SIGNAL_EVENT_LIMIT/64) {
+ 			/* With relatively few events, it's faster to
+ 			 * iterate over the event IDR
+ 			 */
+-- 
+2.7.4
+