[Intel-gfx] [PATCH] drm/i915: Limit the backpressure for i915_request allocation

[Chris Wilson]

If we try and fail to allocate a i915_request, we apply some
backpressure on the clients to throttle the memory allocations coming
from i915.ko. Currently, we wait until completely idle, but this is far
too heavy and leads to some situations where the only escape is to
declare a client hung and reset the GPU. The intent is to only ratelimit
the allocation requests, so we need only wait for a jiffie before using
the normal direct reclaim.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106680
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_request.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 09ed48833b54..588bc5a4d18b 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -736,7 +736,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 		ret = i915_gem_wait_for_idle(i915,
 					     I915_WAIT_LOCKED |
 					     I915_WAIT_INTERRUPTIBLE,
-					     MAX_SCHEDULE_TIMEOUT);
+					     1);
 		if (ret)
 			goto err_unreserve;
 
-- 
2.19.0