From 1637ef413b9a5d1c14eb370f7029a5558f3bb3d3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 20 Apr 2010 17:10:35 +0100 Subject: [PATCH] drm/i915: Wait for the GPU whilst shrinking, if truly desperate. By idling the GPU and discarding everything we can when under extreme memory pressure, the number of OOM-killer events is dramatically reduced. For instance, this makes it possible to run firefox-planet-gnome.trace again on my swapless 512MiB i915. Signed-off-by: Chris Wilson Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/i915_gem.c | 45 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 47c46ed..3471dec 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -5066,6 +5066,20 @@ void i915_gem_release(struct drm_device * dev, struct drm_file *file_priv) } static int +i915_gpu_is_active(struct drm_device *dev) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + int lists_empty; + + spin_lock(&dev_priv->mm.active_list_lock); + lists_empty = list_empty(&dev_priv->mm.flushing_list) && + list_empty(&dev_priv->mm.active_list); + spin_unlock(&dev_priv->mm.active_list_lock); + + return !lists_empty; +} + +static int i915_gem_shrink(int nr_to_scan, gfp_t gfp_mask) { drm_i915_private_t *dev_priv, *next_dev; @@ -5094,6 +5108,7 @@ i915_gem_shrink(int nr_to_scan, gfp_t gfp_mask) spin_lock(&shrink_list_lock); +rescan: /* first scan for clean buffers */ list_for_each_entry_safe(dev_priv, next_dev, &shrink_list, mm.shrink_list) { @@ -5151,6 +5166,36 @@ i915_gem_shrink(int nr_to_scan, gfp_t gfp_mask) would_deadlock = 0; } + if (nr_to_scan) { + int active = 0; + + /* + * We are desperate for pages, so as a last resort, wait + * for the GPU to finish and discard whatever we can. + * This has a dramatic impact to reduce the number of + * OOM-killer events whilst running the GPU aggressively. + */ + list_for_each_entry(dev_priv, &shrink_list, mm.shrink_list) { + struct drm_device *dev = dev_priv->dev; + + if (!mutex_trylock(&dev->struct_mutex)) + continue; + + spin_unlock(&shrink_list_lock); + + if (i915_gpu_is_active(dev)) { + i915_gpu_idle(dev); + active++; + } + + spin_lock(&shrink_list_lock); + mutex_unlock(&dev->struct_mutex); + } + + if (active) + goto rescan; + } + spin_unlock(&shrink_list_lock); if (would_deadlock) -- 2.7.4