From ee941e18a3c05a7589b690669611c3f0895a2d5a Mon Sep 17 00:00:00 2001
From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Date: Sun, 3 Aug 2014 20:00:40 +0900 Subject: [PATCH 2/5] gpu/drm/ttm: Choose a pool to shrink correctly in ttm_dma_pool_shrink_scan().
We can use "unsigned int" instead of "atomic_t" by updating start_pool variable under _manager->lock. This patch will make it possible to avoid skipping when choosing a pool to shrink in round-robin style, after next patch changes mutex_lock(_manager->lock) to !mutex_trylock(_manager->lork).
Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: stable stable@kernel.org [3.3+] --- drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index b751fff..d8e59f7 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -1004,9 +1004,9 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); static unsigned long ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { - static atomic_t start_pool = ATOMIC_INIT(0); + static unsigned start_pool; unsigned idx = 0; - unsigned pool_offset = atomic_add_return(1, &start_pool); + unsigned pool_offset; unsigned shrink_pages = sc->nr_to_scan; struct device_pools *p; unsigned long freed = 0; @@ -1017,7 +1017,7 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) mutex_lock(&_manager->lock); if (!_manager->npools) goto out; - pool_offset = pool_offset % _manager->npools; + pool_offset = ++start_pool % _manager->npools; list_for_each_entry(p, &_manager->pools, pools) { unsigned nr_free;