Re: [PATCH] drm/ttm: make the pool shrinker lock a mutex

On Tue, Jan 12, 2021 at 06:49:18PM +0800, Christian König wrote:

Ping? Ray can I get an acked-by? It's an important bug fix.

Thanks, Christian.

Am 11.01.21 um 14:57 schrieb Christian König:

...

set_pages_wb() might sleep and so we can't do this in an atomic context.

Signed-off-by: Christian König christian.koenig@amd.com Reported-by: Mikhail Gavrilov mikhail.v.gavrilov@gmail.com Fixes: d099fc8f540a ("drm/ttm: new TT backend allocation pool v3")

Sorry, missed this mail yesterday.

Patch looks good for me.

Reviewed-by: Huang Rui ray.huang@amd.com

...

---

drivers/gpu/drm/ttm/ttm_pool.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c index a00b7ab9c14c..6a6eeba423d1 100644 --- a/drivers/gpu/drm/ttm/ttm_pool.c +++ b/drivers/gpu/drm/ttm/ttm_pool.c @@ -66,7 +66,7 @@ static struct ttm_pool_type global_uncached[MAX_ORDER]; static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER]; static struct ttm_pool_type global_dma32_uncached[MAX_ORDER];

-static spinlock_t shrinker_lock; +static struct mutex shrinker_lock; static struct list_head shrinker_list; static struct shrinker mm_shrinker;

@@ -249,9 +249,9 @@ static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool, spin_lock_init(&pt->lock); INIT_LIST_HEAD(&pt->pages);

• spin_lock(&shrinker_lock);

• mutex_lock(&shrinker_lock); list_add_tail(&pt->shrinker_list, &shrinker_list);

• spin_unlock(&shrinker_lock);

• mutex_unlock(&shrinker_lock); }

  /* Remove a pool_type from the global shrinker list and free all pages */

@@ -259,9 +259,9 @@ static void ttm_pool_type_fini(struct ttm_pool_type *pt) { struct page *p, *tmp;

• spin_lock(&shrinker_lock);

• mutex_lock(&shrinker_lock); list_del(&pt->shrinker_list);

• spin_unlock(&shrinker_lock);

• mutex_unlock(&shrinker_lock);

  list_for_each_entry_safe(p, tmp, &pt->pages, lru) ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);

@@ -302,7 +302,7 @@ static unsigned int ttm_pool_shrink(void) unsigned int num_freed; struct page *p;

• spin_lock(&shrinker_lock);

• mutex_lock(&shrinker_lock); pt = list_first_entry(&shrinker_list, typeof(*pt), shrinker_list);

  p = ttm_pool_type_take(pt);

@@ -314,7 +314,7 @@ static unsigned int ttm_pool_shrink(void) }

list_move_tail(&pt->shrinker_list, &shrinker_list);

• spin_unlock(&shrinker_lock);

• mutex_unlock(&shrinker_lock);

  return num_freed; }

@@ -564,7 +564,7 @@ int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m) { unsigned int i;

• spin_lock(&shrinker_lock);

• mutex_lock(&shrinker_lock);

  seq_puts(m, "\t "); for (i = 0; i < MAX_ORDER; ++i)

@@ -600,7 +600,7 @@ int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m) seq_printf(m, "\ntotal\t: %8lu of %8lu\n", atomic_long_read(&allocated_pages), page_pool_size);

• spin_unlock(&shrinker_lock);

• mutex_unlock(&shrinker_lock);

  return 0; }

@@ -644,7 +644,7 @@ int ttm_pool_mgr_init(unsigned long num_pages) if (!page_pool_size) page_pool_size = num_pages;

• spin_lock_init(&shrinker_lock);

• mutex_init(&shrinker_lock); INIT_LIST_HEAD(&shrinker_list);

  for (i = 0; i < MAX_ORDER; ++i) {