freedreno: add bo cache

Workloads which create many transient buffers cause significant CPU
overhead in buffer allocation, zeroing, cache maint, and mmap setup.
By caching and re-using existing buffers, the CPU overhead drops
significantly.  See:

http://bloggingthemonkey.blogspot.com/2013/09/freedreno-update-moar-fps.html

A simple time based policy is used for purging the cache.  Once the
kernel supports it, we could use madvise style API to handle memory
pressure scenarios a bit better.

Signed-off-by: Rob Clark <robclark@freedesktop.org>

1 files changed, 56 insertions, 4 deletions

diff --git a/freedreno/freedreno_device.c b/freedreno/freedreno_device.c
index 1e3d9df2..6486983d 100644
--- a/freedreno/freedreno_device.c
+++ b/freedreno/freedreno_device.c
@@ -39,6 +39,44 @@ static void * dev_table;
 struct fd_device * kgsl_device_new(int fd);
 struct fd_device * msm_device_new(int fd);
 
+static void
+add_bucket(struct fd_device *dev, int size)
+{
+        unsigned int i = dev->num_buckets;
+
+        assert(i < ARRAY_SIZE(dev->cache_bucket));
+
+        list_inithead(&dev->cache_bucket[i].list);
+        dev->cache_bucket[i].size = size;
+        dev->num_buckets++;
+}
+
+static void
+init_cache_buckets(struct fd_device *dev)
+{
+        unsigned long size, cache_max_size = 64 * 1024 * 1024;
+
+        /* OK, so power of two buckets was too wasteful of memory.
+         * Give 3 other sizes between each power of two, to hopefully
+         * cover things accurately enough.  (The alternative is
+         * probably to just go for exact matching of sizes, and assume
+         * that for things like composited window resize the tiled
+         * width/height alignment and rounding of sizes to pages will
+         * get us useful cache hit rates anyway)
+         */
+        add_bucket(dev, 4096);
+        add_bucket(dev, 4096 * 2);
+        add_bucket(dev, 4096 * 3);
+
+        /* Initialize the linked lists for BO reuse cache. */
+        for (size = 4 * 4096; size <= cache_max_size; size *= 2) {
+                add_bucket(dev, size);
+                add_bucket(dev, size + size * 1 / 4);
+                add_bucket(dev, size + size * 2 / 4);
+                add_bucket(dev, size + size * 3 / 4);
+        }
+}
+
 static struct fd_device * fd_device_new_impl(int fd)
 {
         struct fd_device *dev;
@@ -69,6 +107,7 @@ static struct fd_device * fd_device_new_impl(int fd)
         dev->fd = fd;
         dev->handle_table = drmHashCreate();
         dev->name_table = drmHashCreate();
+        init_cache_buckets(dev);
 
         return dev;
 }
@@ -102,14 +141,27 @@ struct fd_device * fd_device_ref(struct fd_device *dev)
         return dev;
 }
 
+static void fd_device_del_impl(struct fd_device *dev)
+{
+        fd_cleanup_bo_cache(dev, 0);
+        drmHashDestroy(dev->handle_table);
+        drmHashDestroy(dev->name_table);
+        drmHashDelete(dev_table, dev->fd);
+        dev->funcs->destroy(dev);
+}
+
+void fd_device_del_locked(struct fd_device *dev)
+{
+        if (!atomic_dec_and_test(&dev->refcnt))
+                return;
+        fd_device_del_impl(dev);
+}
+
 void fd_device_del(struct fd_device *dev)
 {
         if (!atomic_dec_and_test(&dev->refcnt))
                 return;
         pthread_mutex_lock(&table_lock);
-        drmHashDestroy(dev->handle_table);
-        drmHashDestroy(dev->name_table);
-        drmHashDelete(dev_table, dev->fd);
+        fd_device_del_impl(dev);
         pthread_mutex_unlock(&table_lock);
-        dev->funcs->destroy(dev);
 }