drm/i915: Shrink the request kmem_cache on allocation error (f0111b04) · Commits · 戴 / test

If we fail to allocate a new request, make sure we recover the pages that are in the process of being freed by inserting an RCU barrier. v2: Comment before the shrink and barrier in the error path. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180119144657.22606-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_request.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -696,6 +696,17 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
		if (ret)
		goto err_unreserve;

		/*
		* We've forced the client to stall and catch up with whatever
		* backlog there might have been. As we are assuming that we
		* caused the mempressure, now is an opportune time to
		* recover as much memory from the request pool as is possible.
		* Having already penalized the client to stall, we spend
		* a little extra time to re-optimise page allocation.
		*/
		kmem_cache_shrink(dev_priv->requests);
		rcu_barrier(); /* Recover the TYPESAFE_BY_RCU pages */

		req = kmem_cache_alloc(dev_priv->requests, GFP_KERNEL);
		if (!req) {
		ret = -ENOMEM;

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