broadcom/vc4: Mark BOs as purgeable when they enter the BO cache
This patch makes use of the DRM_IOCTL_VC4_GEM_MADVISE ioctl to mark all
BOs placed in the mesa BO cache as purgeable so that the system can
reclaim this memory under memory pressure.
v2:
- Removed BOs from the cache when they've been purged by the kernel
- Check whether the madvise ioctl is supported or not before using it
v3: Don't walk the whole list when we find a busy BO (by anholt, acked by
Boris)
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
diff --git a/src/gallium/drivers/vc4/vc4_bufmgr.c b/src/gallium/drivers/vc4/vc4_bufmgr.c
index d06d55f..274c4c3 100644
--- a/src/gallium/drivers/vc4/vc4_bufmgr.c
+++ b/src/gallium/drivers/vc4/vc4_bufmgr.c
@@ -113,35 +113,105 @@
cache->bo_size -= bo->size;
}
+static void vc4_bo_purgeable(struct vc4_bo *bo)
+{
+ struct drm_vc4_gem_madvise arg = {
+ .handle = bo->handle,
+ .madv = VC4_MADV_DONTNEED,
+ };
+
+ if (bo->screen->has_madvise)
+ vc4_ioctl(bo->screen->fd, DRM_IOCTL_VC4_GEM_MADVISE, &arg);
+}
+
+static bool vc4_bo_unpurgeable(struct vc4_bo *bo)
+{
+ struct drm_vc4_gem_madvise arg = {
+ .handle = bo->handle,
+ .madv = VC4_MADV_WILLNEED,
+ };
+
+ if (!bo->screen->has_madvise)
+ return true;
+
+ if (vc4_ioctl(bo->screen->fd, DRM_IOCTL_VC4_GEM_MADVISE, &arg))
+ return false;
+
+ return arg.retained;
+}
+
+static void
+vc4_bo_free(struct vc4_bo *bo)
+{
+ struct vc4_screen *screen = bo->screen;
+
+ if (bo->map) {
+ if (using_vc4_simulator && bo->name &&
+ strcmp(bo->name, "winsys") == 0) {
+ free(bo->map);
+ } else {
+ munmap(bo->map, bo->size);
+ VG(VALGRIND_FREELIKE_BLOCK(bo->map, 0));
+ }
+ }
+
+ struct drm_gem_close c;
+ memset(&c, 0, sizeof(c));
+ c.handle = bo->handle;
+ int ret = vc4_ioctl(screen->fd, DRM_IOCTL_GEM_CLOSE, &c);
+ if (ret != 0)
+ fprintf(stderr, "close object %d: %s\n", bo->handle, strerror(errno));
+
+ screen->bo_count--;
+ screen->bo_size -= bo->size;
+
+ if (dump_stats) {
+ fprintf(stderr, "Freed %s%s%dkb:\n",
+ bo->name ? bo->name : "",
+ bo->name ? " " : "",
+ bo->size / 1024);
+ vc4_bo_dump_stats(screen);
+ }
+
+ free(bo);
+}
+
static struct vc4_bo *
vc4_bo_from_cache(struct vc4_screen *screen, uint32_t size, const char *name)
{
struct vc4_bo_cache *cache = &screen->bo_cache;
uint32_t page_index = size / 4096 - 1;
+ struct vc4_bo *iter, *tmp, *bo = NULL;
if (cache->size_list_size <= page_index)
return NULL;
- struct vc4_bo *bo = NULL;
mtx_lock(&cache->lock);
- if (!list_empty(&cache->size_list[page_index])) {
- bo = LIST_ENTRY(struct vc4_bo, cache->size_list[page_index].next,
- size_list);
-
- /* Check that the BO has gone idle. If not, then we want to
- * allocate something new instead, since we assume that the
- * user will proceed to CPU map it and fill it with stuff.
+ LIST_FOR_EACH_ENTRY_SAFE(iter, tmp, &cache->size_list[page_index],
+ size_list) {
+ /* Check that the BO has gone idle. If not, then none of the
+ * other BOs (pushed to the list after later rendering) are
+ * likely to be idle, either.
*/
- if (!vc4_bo_wait(bo, 0, NULL)) {
- mtx_unlock(&cache->lock);
- return NULL;
- }
+ if (!vc4_bo_wait(iter, 0, NULL))
+ break;
+ if (!vc4_bo_unpurgeable(iter)) {
+ /* The BO has been purged. Free it and try to find
+ * another one in the cache.
+ */
+ vc4_bo_remove_from_cache(cache, iter);
+ vc4_bo_free(iter);
+ continue;
+ }
+
+ bo = iter;
pipe_reference_init(&bo->reference, 1);
vc4_bo_remove_from_cache(cache, bo);
vc4_bo_label(screen, bo, "%s", name);
bo->name = name;
+ break;
}
mtx_unlock(&cache->lock);
return bo;
@@ -221,42 +291,6 @@
}
static void
-vc4_bo_free(struct vc4_bo *bo)
-{
- struct vc4_screen *screen = bo->screen;
-
- if (bo->map) {
- if (using_vc4_simulator && bo->name &&
- strcmp(bo->name, "winsys") == 0) {
- free(bo->map);
- } else {
- munmap(bo->map, bo->size);
- VG(VALGRIND_FREELIKE_BLOCK(bo->map, 0));
- }
- }
-
- struct drm_gem_close c;
- memset(&c, 0, sizeof(c));
- c.handle = bo->handle;
- int ret = vc4_ioctl(screen->fd, DRM_IOCTL_GEM_CLOSE, &c);
- if (ret != 0)
- fprintf(stderr, "close object %d: %s\n", bo->handle, strerror(errno));
-
- screen->bo_count--;
- screen->bo_size -= bo->size;
-
- if (dump_stats) {
- fprintf(stderr, "Freed %s%s%dkb:\n",
- bo->name ? bo->name : "",
- bo->name ? " " : "",
- bo->size / 1024);
- vc4_bo_dump_stats(screen);
- }
-
- free(bo);
-}
-
-static void
free_stale_bos(struct vc4_screen *screen, time_t time)
{
struct vc4_bo_cache *cache = &screen->bo_cache;
@@ -325,6 +359,7 @@
cache->size_list_size = page_index + 1;
}
+ vc4_bo_purgeable(bo);
bo->free_time = time;
list_addtail(&bo->size_list, &cache->size_list[page_index]);
list_addtail(&bo->time_list, &cache->time_list);
diff --git a/src/gallium/drivers/vc4/vc4_screen.c b/src/gallium/drivers/vc4/vc4_screen.c
index 8128ee6..7f44fed 100644
--- a/src/gallium/drivers/vc4/vc4_screen.c
+++ b/src/gallium/drivers/vc4/vc4_screen.c
@@ -692,6 +692,8 @@
vc4_has_feature(screen, DRM_VC4_PARAM_SUPPORTS_ETC1);
screen->has_threaded_fs =
vc4_has_feature(screen, DRM_VC4_PARAM_SUPPORTS_THREADED_FS);
+ screen->has_madvise =
+ vc4_has_feature(screen, DRM_VC4_PARAM_SUPPORTS_MADVISE);
if (!vc4_get_chip_info(screen))
goto fail;
diff --git a/src/gallium/drivers/vc4/vc4_screen.h b/src/gallium/drivers/vc4/vc4_screen.h
index 8510821..09d1c34 100644
--- a/src/gallium/drivers/vc4/vc4_screen.h
+++ b/src/gallium/drivers/vc4/vc4_screen.h
@@ -95,6 +95,7 @@
bool has_control_flow;
bool has_etc1;
bool has_threaded_fs;
+ bool has_madvise;
bool has_tiling_ioctl;
struct vc4_simulator_file *sim_file;