Part of the attraction of using a recursive batch is that it is
hard on the system (executing the "function" call is apparently
quite expensive). However, the GPU may hog the entire system for
a few minutes, preventing even NMI. Quite why this is so is unclear,
but presumably it relates to the PM_INTRMSK workaround on gen6/gen7.
If we give the system a break by having the GPU execute a few nops
between function calls, that appears enough to keep SNB out of
trouble.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tomi Sarvela <tomi.p.sarvela@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
lib/igt_dummyload.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/lib/igt_dummyload.c b/lib/igt_dummyload.c
index 00c6a030..c6e57cff 100644
--- a/lib/igt_dummyload.c
+++ b/lib/igt_dummyload.c
@@ -103,7 +103,7 @@ static void emit_recursive_batch(igt_spin_t *spin,
/* dummy write to dependency */
obj[SCRATCH].handle = dep;
fill_reloc(&relocs[obj[BATCH].relocation_count++],
- dep, 256,
+ dep, 1020,
I915_GEM_DOMAIN_RENDER,
I915_GEM_DOMAIN_RENDER);
execbuf.buffer_count++;
@@ -112,9 +112,23 @@ static void emit_recursive_batch(igt_spin_t *spin,
spin->batch = batch;
spin->handle = obj[BATCH].handle;
+ /* Pad with a few nops so that we do not completely hog the system.
+ *
+ * Part of the attraction of using a recursive batch is that it is
+ * hard on the system (executing the "function" call is apparently
+ * quite expensive). However, the GPU may hog the entire system for
+ * a few minutes, preventing even NMI. Quite why this is so is unclear,
+ * but presumably it relates to the PM_INTRMSK workaround on gen6/gen7.
+ * If we give the system a break by having the GPU execute a few nops
+ * between function calls, that appears enough to keep SNB out of
+ * trouble. See https://
+ */
+ batch += 1000;
+
/* recurse */
fill_reloc(&relocs[obj[BATCH].relocation_count],
- obj[BATCH].handle, 1, I915_GEM_DOMAIN_COMMAND, 0);
+ obj[BATCH].handle, (batch - spin->batch) + 1,
+ I915_GEM_DOMAIN_COMMAND, 0);
if (gen >= 8) {
*batch++ = MI_BATCH_BUFFER_START | 1 << 8 | 1;
*batch++ = 0;
--
2.14.1
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
