From 74e21ac2ccdc5e8f310d536ffe66d22571ece5c5 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 20 Jan 2014 10:17:37 +0000 Subject: [PATCH] drm/i915: Repeat evictions whilst pageflip completions are outstanding Since an old pageflip will keep its scanout buffer object pinned until it has executed its unpin task on the common workqueue, we can clog up our GGTT with stale pinned objects. As we cannot flush those workqueues without dropping our locks, we have to resort to falling back to userspace and telling them to repeat the operation in order to have a chance to run our workqueues and free up the required memory. If we fail, then we are forced to report ENOSPC back to userspace causing the operation to fail and best-case scenario is that it introduces temporary corruption. Signed-off-by: Chris Wilson Reviewed-by: Jon Bloomfield Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_evict.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c index 8f3adc7..2ca280f 100644 --- a/drivers/gpu/drm/i915/i915_gem_evict.c +++ b/drivers/gpu/drm/i915/i915_gem_evict.c @@ -27,8 +27,10 @@ */ #include -#include "i915_drv.h" #include + +#include "i915_drv.h" +#include "intel_drv.h" #include "i915_trace.h" static bool @@ -53,6 +55,7 @@ i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm, struct list_head eviction_list, unwind_list; struct i915_vma *vma; int ret = 0; + int pass = 0; trace_i915_gem_evict(dev, min_size, alignment, mappable); @@ -119,14 +122,24 @@ none: /* Can we unpin some objects such as idle hw contents, * or pending flips? */ - ret = nonblocking ? -ENOSPC : i915_gpu_idle(dev); - if (ret) - return ret; + if (nonblocking) + return -ENOSPC; /* Only idle the GPU and repeat the search once */ - i915_gem_retire_requests(dev); - nonblocking = true; - goto search_again; + if (pass++ == 0) { + ret = i915_gpu_idle(dev); + if (ret) + return ret; + + i915_gem_retire_requests(dev); + goto search_again; + } + + /* If we still have pending pageflip completions, drop + * back to userspace to give our workqueues time to + * acquire our locks and unpin the old scanouts. + */ + return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC; found: /* drm_mm doesn't allow any other other operations while -- 2.7.4