shrink_slab() allows us to report back the number of objects we successfully scanned (out of the target shrinkctl->nr_to_scan). As report the number of pages owned by each GEM object as a separate item to the shrinker, we cannot precisely control the number of shrinker objects we scan on each pass; and indeed may free more than requested. If we fail to tell the shrinker about the number of objects we process, it will continue to hold a grudge against us as any objects left unscanned are added to the next reclaim -- and so we will keep on "unfairly" shrinking our own slab in comparison to other slabs. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Shaohua Li <shli@xxxxxx> Cc: linux-mm@xxxxxxxxx --- drivers/gpu/drm/i915/i915_debugfs.c | 4 ++-- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem.c | 4 ++-- drivers/gpu/drm/i915/i915_gem_gtt.c | 2 +- drivers/gpu/drm/i915/i915_gem_shrinker.c | 24 ++++++++++++++++++------ 5 files changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 6bad53f89738..ed979cc6fb5d 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4338,10 +4338,10 @@ i915_drop_caches_set(void *data, u64 val) lockdep_set_current_reclaim_state(GFP_KERNEL); if (val & DROP_BOUND) - i915_gem_shrink(dev_priv, LONG_MAX, I915_SHRINK_BOUND); + i915_gem_shrink(dev_priv, LONG_MAX, NULL, I915_SHRINK_BOUND); if (val & DROP_UNBOUND) - i915_gem_shrink(dev_priv, LONG_MAX, I915_SHRINK_UNBOUND); + i915_gem_shrink(dev_priv, LONG_MAX, NULL, I915_SHRINK_UNBOUND); if (val & DROP_SHRINK_ALL) i915_gem_shrink_all(dev_priv); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index b78605a9f1b5..c3299eaac1af 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3752,6 +3752,7 @@ i915_gem_object_create_internal(struct drm_i915_private *dev_priv, /* i915_gem_shrinker.c */ unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv, unsigned long target, + unsigned long *nr_scanned, unsigned flags); #define I915_SHRINK_PURGEABLE 0x1 #define I915_SHRINK_UNBOUND 0x2 diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a2714898ff01..c06091718bb4 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2339,7 +2339,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) goto err_sg; } - i915_gem_shrink(dev_priv, 2 * page_count, *s++); + i915_gem_shrink(dev_priv, 2 * page_count, NULL, *s++); cond_resched(); /* We've tried hard to allocate the memory by reaping @@ -5037,7 +5037,7 @@ int i915_gem_freeze_late(struct drm_i915_private *dev_priv) * the objects as well, see i915_gem_freeze() */ - i915_gem_shrink(dev_priv, -1UL, I915_SHRINK_UNBOUND); + i915_gem_shrink(dev_priv, -1UL, NULL, I915_SHRINK_UNBOUND); i915_gem_drain_freed_objects(dev_priv); spin_lock(&dev_priv->mm.obj_lock); diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index b6d5f1c6ef5e..8394fc2a21eb 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -2062,7 +2062,7 @@ int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj, */ GEM_BUG_ON(obj->mm.pages == pages); } while (i915_gem_shrink(to_i915(obj->base.dev), - obj->base.size >> PAGE_SHIFT, + obj->base.size >> PAGE_SHIFT, NULL, I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_ACTIVE)); diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c index ee4df98f009d..c178a1c9ae47 100644 --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c @@ -198,6 +198,7 @@ static void __start_writeback(struct drm_i915_gem_object *obj) * i915_gem_shrink - Shrink buffer object caches * @dev_priv: i915 device * @target: amount of memory to make available, in pages + * @nr_scanned: optional output for number of pages scanned (incremental) * @flags: control flags for selecting cache types * * This function is the main interface to the shrinker. It will try to release @@ -220,7 +221,9 @@ static void __start_writeback(struct drm_i915_gem_object *obj) */ unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv, - unsigned long target, unsigned flags) + unsigned long target, + unsigned long *nr_scanned, + unsigned flags) { const struct { struct list_head *list; @@ -231,6 +234,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, { NULL, 0 }, }, *phase; unsigned long count = 0; + unsigned long scanned = 0; bool unlock; if (!shrinker_lock(dev_priv, &unlock)) @@ -318,6 +322,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, } mutex_unlock(&obj->mm.lock); } + scanned += obj->base.size >> PAGE_SHIFT; spin_lock(&dev_priv->mm.obj_lock); } @@ -332,6 +337,8 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, shrinker_unlock(dev_priv, unlock); + if (nr_scanned) + *nr_scanned += scanned; return count; } @@ -354,7 +361,7 @@ unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv) unsigned long freed; intel_runtime_pm_get(dev_priv); - freed = i915_gem_shrink(dev_priv, -1UL, + freed = i915_gem_shrink(dev_priv, -1UL, NULL, I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_ACTIVE); @@ -411,23 +418,28 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) unsigned long freed; bool unlock; + sc->nr_scanned = 0; + if (!shrinker_lock(dev_priv, &unlock)) return SHRINK_STOP; freed = i915_gem_shrink(dev_priv, sc->nr_to_scan, + &sc->nr_scanned, I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_PURGEABLE); if (freed < sc->nr_to_scan) freed += i915_gem_shrink(dev_priv, - sc->nr_to_scan - freed, + sc->nr_to_scan - sc->nr_scanned, + &sc->nr_scanned, I915_SHRINK_BOUND | I915_SHRINK_UNBOUND); if (freed < sc->nr_to_scan && current_is_kswapd()) { intel_runtime_pm_get(dev_priv); freed += i915_gem_shrink(dev_priv, - sc->nr_to_scan - freed, + sc->nr_to_scan - sc->nr_scanned, + &sc->nr_scanned, I915_SHRINK_ACTIVE | I915_SHRINK_BOUND | I915_SHRINK_UNBOUND); @@ -436,7 +448,7 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) shrinker_unlock(dev_priv, unlock); - return freed; + return sc->nr_scanned ? freed : SHRINK_STOP; } static bool @@ -525,7 +537,7 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr goto out; intel_runtime_pm_get(dev_priv); - freed_pages += i915_gem_shrink(dev_priv, -1UL, + freed_pages += i915_gem_shrink(dev_priv, -1UL, NULL, I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_ACTIVE | -- 2.14.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx