[Intel-gfx] [PATCH v2] drm/i915/gem: reschedule relocations to avoid timeouts

[S A Muqthyar Ahmed]

Platforms with greater system memory will need to relocate more entries.
It may lead to soft hangs.

Adding cond_resched() for rescheduling process to avoid timeouts.

Suggested-by: Chris Wilson <chris.p.wil...@intel.com>
Signed-off-by: S A Muqthyar Ahmed <syed.abdul.muqthyar.ah...@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c 
b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index b7b2c14fd9e15e..25ab4b9e20049e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1551,6 +1551,11 @@ static int eb_relocate_vma(struct i915_execbuffer *eb, 
struct eb_vma *ev)
                        }
                } while (r++, --count);
                urelocs += ARRAY_SIZE(stack);
+
+               if (need_resched()) {
+                       reloc_cache_reset(&eb->reloc_cache, eb);
+                       cond_resched();
+               }
        } while (remain);
 out:
        reloc_cache_reset(&eb->reloc_cache, eb);
@@ -1564,18 +1569,19 @@ eb_relocate_vma_slow(struct i915_execbuffer *eb, struct 
eb_vma *ev)
        struct drm_i915_gem_relocation_entry *relocs =
                u64_to_ptr(typeof(*relocs), entry->relocs_ptr);
        unsigned int i;
-       int err;
+       int err = 0;
 
-       for (i = 0; i < entry->relocation_count; i++) {
+       for (i = 0; !err && i < entry->relocation_count; i++) {
                u64 offset = eb_relocate_entry(eb, ev, &relocs[i]);
 
-               if ((s64)offset < 0) {
+               if ((s64)offset < 0)
                        err = (int)offset;
-                       goto err;
+
+               if (need_resched()) {
+                       reloc_cache_reset(&eb->reloc_cache, eb);
+                       cond_resched();
                }
        }
-       err = 0;
-err:
        reloc_cache_reset(&eb->reloc_cache, eb);
        return err;
 }
-- 
2.25.1