drm/i915: Restrict wait to client's timeline on i915_request alloc failure

Commit Message

Chris Wilson Sept. 12, 2018, 3:02 p.m. UTC

Let's try not to overly penalize the unlucky client by making them wait
for others to complete their work, and only apply the ratelimit if they
themselves have outstanding work. Still, we apply global reclaim to the
client (we need to scavenge some memory for it) so it doesn't got away
completely scot free.

Signed-off-by: Chris Wilson <[e-mail]>
Cc: Tvrtko Ursulin <[e-mail]>
Cc: Joonas Lahtinen <[e-mail]>
---
 drivers/gpu/drm/i915/i915_request.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 588bc5a4d18b..72bcb4ca0c45 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -733,12 +733,16 @@  i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 			      GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
 	if (unlikely(!rq)) {
 		/* Ratelimit ourselves to prevent oom from malicious clients */
-		ret = i915_gem_wait_for_idle(i915,
-					     I915_WAIT_LOCKED |
-					     I915_WAIT_INTERRUPTIBLE,
-					     1);
-		if (ret)
+		rq = i915_gem_active_raw(&ce->ring->timeline->last_request,
+					 &i915->drm.struct_mutex);
+		if (rq && i915_request_wait(rq,
+					    I915_WAIT_LOCKED |
+					    I915_WAIT_INTERRUPTIBLE,
+					    1) == -EINTR) {
+			ret = -EINTR;
 			goto err_unreserve;
+		}
+		i915_retire_requests(i915);
 
 		/*
 		 * We've forced the client to stall and catch up with whatever