From 21a22a61c02a1d1807ff03df8eb8fa16ebdd1b74 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 29 May 2015 18:06:32 -0700 Subject: [PATCH] vc4: Make sure we allocate idle BOs from the cache. We were returning the most recently freed BO, without checking if it was idle yet. This meant that we generally stalled immediately on the previous frame when generating a new one. Instead, allocate new BOs when the *oldest* BO is still busy, so that the cache scales with how much is needed to keep some frames outstanding, as originally intended. Note that if you don't have some throttling happening, this means that you can accidentally run the system out of memory. The kernel is now applying some throttling on all execs, to hopefully avoid this. --- src/gallium/drivers/vc4/vc4_bufmgr.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/src/gallium/drivers/vc4/vc4_bufmgr.c b/src/gallium/drivers/vc4/vc4_bufmgr.c index 8f9d9c3ff77..8d976707791 100644 --- a/src/gallium/drivers/vc4/vc4_bufmgr.c +++ b/src/gallium/drivers/vc4/vc4_bufmgr.c @@ -49,8 +49,18 @@ vc4_bo_from_cache(struct vc4_screen *screen, uint32_t size, const char *name) struct vc4_bo *bo = NULL; pipe_mutex_lock(cache->lock); if (!is_empty_list(&cache->size_list[page_index])) { - struct simple_node *node = last_elem(&cache->size_list[page_index]); + struct simple_node *node = first_elem(&cache->size_list[page_index]); bo = container_of(node, struct vc4_bo, 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. + */ + if (!vc4_bo_wait(bo, 0)) { + pipe_mutex_unlock(cache->lock); + return NULL; + } + pipe_reference_init(&bo->reference, 1); remove_from_list(&bo->time_list); remove_from_list(&bo->size_list); -- 2.11.0