510 lines
14 KiB
Diff
510 lines
14 KiB
Diff
From: Eric Anholt <eric@anholt.net>
|
|
Date: Fri, 9 Oct 2015 20:25:07 -0700
|
|
Subject: [01/16] drm/vc4: Add a BO cache.
|
|
Origin: http://cgit.freedesktop.org/~airlied/linux/commit?id=c826a6e1064419f78855463cf29ce9e8b9d25bf4
|
|
|
|
We need to allocate new BOs in the kernel as part of each frame, but
|
|
the CMA allocator is way too slow for that. As an optimization, keep
|
|
track of recently-freed BOs and reuse them, with a 1 second timeout to
|
|
fully free them back to the system.
|
|
|
|
This improves 3D performance by about 15%.
|
|
|
|
Signed-off-by: Eric Anholt <eric@anholt.net>
|
|
---
|
|
drivers/gpu/drm/vc4/vc4_bo.c | 336 +++++++++++++++++++++++++++++++++++++-
|
|
drivers/gpu/drm/vc4/vc4_debugfs.c | 1 +
|
|
drivers/gpu/drm/vc4/vc4_drv.c | 6 +-
|
|
drivers/gpu/drm/vc4/vc4_drv.h | 49 +++++-
|
|
4 files changed, 384 insertions(+), 8 deletions(-)
|
|
|
|
diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
|
|
index ab9f510..18faa5b 100644
|
|
--- a/drivers/gpu/drm/vc4/vc4_bo.c
|
|
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
|
|
@@ -12,19 +12,229 @@
|
|
* access to system memory with no MMU in between. To support it, we
|
|
* use the GEM CMA helper functions to allocate contiguous ranges of
|
|
* physical memory for our BOs.
|
|
+ *
|
|
+ * Since the CMA allocator is very slow, we keep a cache of recently
|
|
+ * freed BOs around so that the kernel's allocation of objects for 3D
|
|
+ * rendering can return quickly.
|
|
*/
|
|
|
|
#include "vc4_drv.h"
|
|
|
|
-struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t size)
|
|
+static void vc4_bo_stats_dump(struct vc4_dev *vc4)
|
|
+{
|
|
+ DRM_INFO("num bos allocated: %d\n",
|
|
+ vc4->bo_stats.num_allocated);
|
|
+ DRM_INFO("size bos allocated: %dkb\n",
|
|
+ vc4->bo_stats.size_allocated / 1024);
|
|
+ DRM_INFO("num bos used: %d\n",
|
|
+ vc4->bo_stats.num_allocated - vc4->bo_stats.num_cached);
|
|
+ DRM_INFO("size bos used: %dkb\n",
|
|
+ (vc4->bo_stats.size_allocated -
|
|
+ vc4->bo_stats.size_cached) / 1024);
|
|
+ DRM_INFO("num bos cached: %d\n",
|
|
+ vc4->bo_stats.num_cached);
|
|
+ DRM_INFO("size bos cached: %dkb\n",
|
|
+ vc4->bo_stats.size_cached / 1024);
|
|
+}
|
|
+
|
|
+#ifdef CONFIG_DEBUG_FS
|
|
+int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
|
|
+{
|
|
+ struct drm_info_node *node = (struct drm_info_node *)m->private;
|
|
+ struct drm_device *dev = node->minor->dev;
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ struct vc4_bo_stats stats;
|
|
+
|
|
+ /* Take a snapshot of the current stats with the lock held. */
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ stats = vc4->bo_stats;
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+
|
|
+ seq_printf(m, "num bos allocated: %d\n",
|
|
+ stats.num_allocated);
|
|
+ seq_printf(m, "size bos allocated: %dkb\n",
|
|
+ stats.size_allocated / 1024);
|
|
+ seq_printf(m, "num bos used: %d\n",
|
|
+ stats.num_allocated - stats.num_cached);
|
|
+ seq_printf(m, "size bos used: %dkb\n",
|
|
+ (stats.size_allocated - stats.size_cached) / 1024);
|
|
+ seq_printf(m, "num bos cached: %d\n",
|
|
+ stats.num_cached);
|
|
+ seq_printf(m, "size bos cached: %dkb\n",
|
|
+ stats.size_cached / 1024);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+#endif
|
|
+
|
|
+static uint32_t bo_page_index(size_t size)
|
|
+{
|
|
+ return (size / PAGE_SIZE) - 1;
|
|
+}
|
|
+
|
|
+/* Must be called with bo_lock held. */
|
|
+static void vc4_bo_destroy(struct vc4_bo *bo)
|
|
{
|
|
+ struct drm_gem_object *obj = &bo->base.base;
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
|
|
+
|
|
+ vc4->bo_stats.num_allocated--;
|
|
+ vc4->bo_stats.size_allocated -= obj->size;
|
|
+ drm_gem_cma_free_object(obj);
|
|
+}
|
|
+
|
|
+/* Must be called with bo_lock held. */
|
|
+static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
|
|
+{
|
|
+ struct drm_gem_object *obj = &bo->base.base;
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
|
|
+
|
|
+ vc4->bo_stats.num_cached--;
|
|
+ vc4->bo_stats.size_cached -= obj->size;
|
|
+
|
|
+ list_del(&bo->unref_head);
|
|
+ list_del(&bo->size_head);
|
|
+}
|
|
+
|
|
+static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
|
|
+ size_t size)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ uint32_t page_index = bo_page_index(size);
|
|
+
|
|
+ if (vc4->bo_cache.size_list_size <= page_index) {
|
|
+ uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
|
|
+ page_index + 1);
|
|
+ struct list_head *new_list;
|
|
+ uint32_t i;
|
|
+
|
|
+ new_list = kmalloc_array(new_size, sizeof(struct list_head),
|
|
+ GFP_KERNEL);
|
|
+ if (!new_list)
|
|
+ return NULL;
|
|
+
|
|
+ /* Rebase the old cached BO lists to their new list
|
|
+ * head locations.
|
|
+ */
|
|
+ for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
|
|
+ struct list_head *old_list =
|
|
+ &vc4->bo_cache.size_list[i];
|
|
+
|
|
+ if (list_empty(old_list))
|
|
+ INIT_LIST_HEAD(&new_list[i]);
|
|
+ else
|
|
+ list_replace(old_list, &new_list[i]);
|
|
+ }
|
|
+ /* And initialize the brand new BO list heads. */
|
|
+ for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
|
|
+ INIT_LIST_HEAD(&new_list[i]);
|
|
+
|
|
+ kfree(vc4->bo_cache.size_list);
|
|
+ vc4->bo_cache.size_list = new_list;
|
|
+ vc4->bo_cache.size_list_size = new_size;
|
|
+ }
|
|
+
|
|
+ return &vc4->bo_cache.size_list[page_index];
|
|
+}
|
|
+
|
|
+void vc4_bo_cache_purge(struct drm_device *dev)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ while (!list_empty(&vc4->bo_cache.time_list)) {
|
|
+ struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
|
|
+ struct vc4_bo, unref_head);
|
|
+ vc4_bo_remove_from_cache(bo);
|
|
+ vc4_bo_destroy(bo);
|
|
+ }
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+}
|
|
+
|
|
+static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
|
|
+ uint32_t size)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ uint32_t page_index = bo_page_index(size);
|
|
+ struct vc4_bo *bo = NULL;
|
|
+
|
|
+ size = roundup(size, PAGE_SIZE);
|
|
+
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ if (page_index >= vc4->bo_cache.size_list_size)
|
|
+ goto out;
|
|
+
|
|
+ if (list_empty(&vc4->bo_cache.size_list[page_index]))
|
|
+ goto out;
|
|
+
|
|
+ bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
|
|
+ struct vc4_bo, size_head);
|
|
+ vc4_bo_remove_from_cache(bo);
|
|
+ kref_init(&bo->base.base.refcount);
|
|
+
|
|
+out:
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+ return bo;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * vc4_gem_create_object - Implementation of driver->gem_create_object.
|
|
+ *
|
|
+ * This lets the CMA helpers allocate object structs for us, and keep
|
|
+ * our BO stats correct.
|
|
+ */
|
|
+struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ struct vc4_bo *bo;
|
|
+
|
|
+ bo = kzalloc(sizeof(*bo), GFP_KERNEL);
|
|
+ if (!bo)
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ vc4->bo_stats.num_allocated++;
|
|
+ vc4->bo_stats.size_allocated += size;
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+
|
|
+ return &bo->base.base;
|
|
+}
|
|
+
|
|
+struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
|
|
+ bool from_cache)
|
|
+{
|
|
+ size_t size = roundup(unaligned_size, PAGE_SIZE);
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
struct drm_gem_cma_object *cma_obj;
|
|
|
|
- cma_obj = drm_gem_cma_create(dev, size);
|
|
- if (IS_ERR(cma_obj))
|
|
+ if (size == 0)
|
|
return NULL;
|
|
- else
|
|
- return to_vc4_bo(&cma_obj->base);
|
|
+
|
|
+ /* First, try to get a vc4_bo from the kernel BO cache. */
|
|
+ if (from_cache) {
|
|
+ struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);
|
|
+
|
|
+ if (bo)
|
|
+ return bo;
|
|
+ }
|
|
+
|
|
+ cma_obj = drm_gem_cma_create(dev, size);
|
|
+ if (IS_ERR(cma_obj)) {
|
|
+ /*
|
|
+ * If we've run out of CMA memory, kill the cache of
|
|
+ * CMA allocations we've got laying around and try again.
|
|
+ */
|
|
+ vc4_bo_cache_purge(dev);
|
|
+
|
|
+ cma_obj = drm_gem_cma_create(dev, size);
|
|
+ if (IS_ERR(cma_obj)) {
|
|
+ DRM_ERROR("Failed to allocate from CMA:\n");
|
|
+ vc4_bo_stats_dump(vc4);
|
|
+ return NULL;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ return to_vc4_bo(&cma_obj->base);
|
|
}
|
|
|
|
int vc4_dumb_create(struct drm_file *file_priv,
|
|
@@ -41,7 +251,7 @@ int vc4_dumb_create(struct drm_file *file_priv,
|
|
if (args->size < args->pitch * args->height)
|
|
args->size = args->pitch * args->height;
|
|
|
|
- bo = vc4_bo_create(dev, roundup(args->size, PAGE_SIZE));
|
|
+ bo = vc4_bo_create(dev, args->size, false);
|
|
if (!bo)
|
|
return -ENOMEM;
|
|
|
|
@@ -50,3 +260,117 @@ int vc4_dumb_create(struct drm_file *file_priv,
|
|
|
|
return ret;
|
|
}
|
|
+
|
|
+/* Must be called with bo_lock held. */
|
|
+static void vc4_bo_cache_free_old(struct drm_device *dev)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
|
|
+
|
|
+ while (!list_empty(&vc4->bo_cache.time_list)) {
|
|
+ struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
|
|
+ struct vc4_bo, unref_head);
|
|
+ if (time_before(expire_time, bo->free_time)) {
|
|
+ mod_timer(&vc4->bo_cache.time_timer,
|
|
+ round_jiffies_up(jiffies +
|
|
+ msecs_to_jiffies(1000)));
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ vc4_bo_remove_from_cache(bo);
|
|
+ vc4_bo_destroy(bo);
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Called on the last userspace/kernel unreference of the BO. Returns
|
|
+ * it to the BO cache if possible, otherwise frees it.
|
|
+ *
|
|
+ * Note that this is called with the struct_mutex held.
|
|
+ */
|
|
+void vc4_free_object(struct drm_gem_object *gem_bo)
|
|
+{
|
|
+ struct drm_device *dev = gem_bo->dev;
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+ struct vc4_bo *bo = to_vc4_bo(gem_bo);
|
|
+ struct list_head *cache_list;
|
|
+
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ /* If the object references someone else's memory, we can't cache it.
|
|
+ */
|
|
+ if (gem_bo->import_attach) {
|
|
+ vc4_bo_destroy(bo);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ /* Don't cache if it was publicly named. */
|
|
+ if (gem_bo->name) {
|
|
+ vc4_bo_destroy(bo);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
|
|
+ if (!cache_list) {
|
|
+ vc4_bo_destroy(bo);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ bo->free_time = jiffies;
|
|
+ list_add(&bo->size_head, cache_list);
|
|
+ list_add(&bo->unref_head, &vc4->bo_cache.time_list);
|
|
+
|
|
+ vc4->bo_stats.num_cached++;
|
|
+ vc4->bo_stats.size_cached += gem_bo->size;
|
|
+
|
|
+ vc4_bo_cache_free_old(dev);
|
|
+
|
|
+out:
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+}
|
|
+
|
|
+static void vc4_bo_cache_time_work(struct work_struct *work)
|
|
+{
|
|
+ struct vc4_dev *vc4 =
|
|
+ container_of(work, struct vc4_dev, bo_cache.time_work);
|
|
+ struct drm_device *dev = vc4->dev;
|
|
+
|
|
+ mutex_lock(&vc4->bo_lock);
|
|
+ vc4_bo_cache_free_old(dev);
|
|
+ mutex_unlock(&vc4->bo_lock);
|
|
+}
|
|
+
|
|
+static void vc4_bo_cache_time_timer(unsigned long data)
|
|
+{
|
|
+ struct drm_device *dev = (struct drm_device *)data;
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+
|
|
+ schedule_work(&vc4->bo_cache.time_work);
|
|
+}
|
|
+
|
|
+void vc4_bo_cache_init(struct drm_device *dev)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+
|
|
+ mutex_init(&vc4->bo_lock);
|
|
+
|
|
+ INIT_LIST_HEAD(&vc4->bo_cache.time_list);
|
|
+
|
|
+ INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
|
|
+ setup_timer(&vc4->bo_cache.time_timer,
|
|
+ vc4_bo_cache_time_timer,
|
|
+ (unsigned long)dev);
|
|
+}
|
|
+
|
|
+void vc4_bo_cache_destroy(struct drm_device *dev)
|
|
+{
|
|
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
|
|
+
|
|
+ del_timer(&vc4->bo_cache.time_timer);
|
|
+ cancel_work_sync(&vc4->bo_cache.time_work);
|
|
+
|
|
+ vc4_bo_cache_purge(dev);
|
|
+
|
|
+ if (vc4->bo_stats.num_allocated) {
|
|
+ DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
|
|
+ vc4_bo_stats_dump(vc4);
|
|
+ }
|
|
+}
|
|
diff --git a/drivers/gpu/drm/vc4/vc4_debugfs.c b/drivers/gpu/drm/vc4/vc4_debugfs.c
|
|
index 4297b0a5..6bcf96e 100644
|
|
--- a/drivers/gpu/drm/vc4/vc4_debugfs.c
|
|
+++ b/drivers/gpu/drm/vc4/vc4_debugfs.c
|
|
@@ -16,6 +16,7 @@
|
|
#include "vc4_regs.h"
|
|
|
|
static const struct drm_info_list vc4_debugfs_list[] = {
|
|
+ {"bo_stats", vc4_bo_stats_debugfs, 0},
|
|
{"hdmi_regs", vc4_hdmi_debugfs_regs, 0},
|
|
{"hvs_regs", vc4_hvs_debugfs_regs, 0},
|
|
{"crtc0_regs", vc4_crtc_debugfs_regs, 0, (void *)(uintptr_t)0},
|
|
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
|
|
index 6e73060..da041fa 100644
|
|
--- a/drivers/gpu/drm/vc4/vc4_drv.c
|
|
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
|
|
@@ -92,7 +92,8 @@ static struct drm_driver vc4_drm_driver = {
|
|
.debugfs_cleanup = vc4_debugfs_cleanup,
|
|
#endif
|
|
|
|
- .gem_free_object = drm_gem_cma_free_object,
|
|
+ .gem_create_object = vc4_create_object,
|
|
+ .gem_free_object = vc4_free_object,
|
|
.gem_vm_ops = &drm_gem_cma_vm_ops,
|
|
|
|
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
|
|
@@ -170,6 +171,8 @@ static int vc4_drm_bind(struct device *dev)
|
|
|
|
drm_dev_set_unique(drm, dev_name(dev));
|
|
|
|
+ vc4_bo_cache_init(drm);
|
|
+
|
|
drm_mode_config_init(drm);
|
|
if (ret)
|
|
goto unref;
|
|
@@ -202,6 +205,7 @@ unbind_all:
|
|
component_unbind_all(dev, drm);
|
|
unref:
|
|
drm_dev_unref(drm);
|
|
+ vc4_bo_cache_destroy(drm);
|
|
return ret;
|
|
}
|
|
|
|
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
|
|
index fd8319f..39a1ff5 100644
|
|
--- a/drivers/gpu/drm/vc4/vc4_drv.h
|
|
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
|
|
@@ -17,6 +17,37 @@ struct vc4_dev {
|
|
struct vc4_crtc *crtc[3];
|
|
|
|
struct drm_fbdev_cma *fbdev;
|
|
+
|
|
+ /* The kernel-space BO cache. Tracks buffers that have been
|
|
+ * unreferenced by all other users (refcounts of 0!) but not
|
|
+ * yet freed, so we can do cheap allocations.
|
|
+ */
|
|
+ struct vc4_bo_cache {
|
|
+ /* Array of list heads for entries in the BO cache,
|
|
+ * based on number of pages, so we can do O(1) lookups
|
|
+ * in the cache when allocating.
|
|
+ */
|
|
+ struct list_head *size_list;
|
|
+ uint32_t size_list_size;
|
|
+
|
|
+ /* List of all BOs in the cache, ordered by age, so we
|
|
+ * can do O(1) lookups when trying to free old
|
|
+ * buffers.
|
|
+ */
|
|
+ struct list_head time_list;
|
|
+ struct work_struct time_work;
|
|
+ struct timer_list time_timer;
|
|
+ } bo_cache;
|
|
+
|
|
+ struct vc4_bo_stats {
|
|
+ u32 num_allocated;
|
|
+ u32 size_allocated;
|
|
+ u32 num_cached;
|
|
+ u32 size_cached;
|
|
+ } bo_stats;
|
|
+
|
|
+ /* Protects bo_cache and the BO stats. */
|
|
+ struct mutex bo_lock;
|
|
};
|
|
|
|
static inline struct vc4_dev *
|
|
@@ -27,6 +58,17 @@ to_vc4_dev(struct drm_device *dev)
|
|
|
|
struct vc4_bo {
|
|
struct drm_gem_cma_object base;
|
|
+
|
|
+ /* List entry for the BO's position in either
|
|
+ * vc4_exec_info->unref_list or vc4_dev->bo_cache.time_list
|
|
+ */
|
|
+ struct list_head unref_head;
|
|
+
|
|
+ /* Time in jiffies when the BO was put in vc4->bo_cache. */
|
|
+ unsigned long free_time;
|
|
+
|
|
+ /* List entry for the BO's position in vc4_dev->bo_cache.size_list */
|
|
+ struct list_head size_head;
|
|
};
|
|
|
|
static inline struct vc4_bo *
|
|
@@ -104,13 +146,18 @@ to_vc4_encoder(struct drm_encoder *encoder)
|
|
#define wait_for(COND, MS) _wait_for(COND, MS, 1)
|
|
|
|
/* vc4_bo.c */
|
|
+struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size);
|
|
void vc4_free_object(struct drm_gem_object *gem_obj);
|
|
-struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t size);
|
|
+struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t size,
|
|
+ bool from_cache);
|
|
int vc4_dumb_create(struct drm_file *file_priv,
|
|
struct drm_device *dev,
|
|
struct drm_mode_create_dumb *args);
|
|
struct dma_buf *vc4_prime_export(struct drm_device *dev,
|
|
struct drm_gem_object *obj, int flags);
|
|
+void vc4_bo_cache_init(struct drm_device *dev);
|
|
+void vc4_bo_cache_destroy(struct drm_device *dev);
|
|
+int vc4_bo_stats_debugfs(struct seq_file *m, void *arg);
|
|
|
|
/* vc4_crtc.c */
|
|
extern struct platform_driver vc4_crtc_driver;
|