From 1a292fa53d06e53000296ba76c6984a43e1e828c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 6 Jan 2017 15:22:39 +0000 Subject: [PATCH] drm/i915: Purge loose pages if we run out of DMA remap space If the DMA remap fails, one cause can be that we have too many objects pinned in a small remapping table, such as swiotlb. (DMA remapping does not trigger the shrinker by itself on its normal failure paths.) So try purging all other objects (using i915_gem_shrink_all(), sparing our own pages as we have yet to assign them to the obj->pages) and try again. If there are no pages to reclaim (and consequently no pages to unmap), the shrinker will report 0 and we fail with -ENOSPC as before. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20170106152240.5793-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_gtt.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 00520f2..f698006 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -2361,10 +2361,24 @@ void i915_gem_suspend_gtt_mappings(struct drm_i915_private *dev_priv) int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj, struct sg_table *pages) { - if (dma_map_sg(&obj->base.dev->pdev->dev, - pages->sgl, pages->nents, - PCI_DMA_BIDIRECTIONAL)) - return 0; + do { + if (dma_map_sg(&obj->base.dev->pdev->dev, + pages->sgl, pages->nents, + PCI_DMA_BIDIRECTIONAL)) + return 0; + + /* If the DMA remap fails, one cause can be that we have + * too many objects pinned in a small remapping table, + * such as swiotlb. Incrementally purge all other objects and + * try again - if there are no more pages to remove from + * the DMA remapper, i915_gem_shrink will return 0. + */ + GEM_BUG_ON(obj->mm.pages == pages); + } while (i915_gem_shrink(to_i915(obj->base.dev), + obj->base.size >> PAGE_SHIFT, + I915_SHRINK_BOUND | + I915_SHRINK_UNBOUND | + I915_SHRINK_ACTIVE)); return -ENOSPC; } -- 2.7.4