[PATCH 4/5] ttm/pool: make pool shrinker NUMA aware

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

This enable NUMA awareness for the shrinker on the
ttm pools.

Cc: Christian Koenig <christian.koenig at amd.com>
Cc: Dave Chinner <david at fromorbit.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/ttm/ttm_pool.c | 35 +++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index ad06f2f8fd2d..902dd682afc0 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -405,12 +405,11 @@ static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
 	return NULL;
 }
 
-/* Free pages using the global shrinker list */
-static unsigned int ttm_pool_shrink(void)
+/* Free pages using the per-node shrinker list */
+static unsigned int ttm_pool_shrink(int nid, unsigned long num_to_free)
 {
 	struct ttm_pool_type *pt;
 	unsigned int num_pages;
-	struct page *p;
 
 	down_read(&pool_shrink_rwsem);
 	spin_lock(&shrinker_lock);
@@ -418,13 +417,8 @@ static unsigned int ttm_pool_shrink(void)
 	list_move_tail(&pt->shrinker_list, &shrinker_list);
 	spin_unlock(&shrinker_lock);
 
-	p = ttm_pool_type_take(pt, ttm_pool_nid(pt->pool));
-	if (p) {
-		ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
-		num_pages = 1 << pt->order;
-	} else {
-		num_pages = 0;
-	}
+	num_pages = list_lru_walk_node(&pt->pages, nid, pool_free_page, pt, &num_to_free);
+	num_pages *= 1 << pt->order;
 	up_read(&pool_shrink_rwsem);
 
 	return num_pages;
@@ -773,6 +767,7 @@ static int __ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 		pt = ttm_pool_select_type(pool, page_caching, order);
 		if (pt && allow_pools)
 			p = ttm_pool_type_take(pt, ttm_pool_nid(pool));
+
 		/*
 		 * If that fails or previously failed, allocate from system.
 		 * Note that this also disallows additional pool allocations using
@@ -921,8 +916,10 @@ void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
 {
 	ttm_pool_free_range(pool, tt, tt->caching, 0, tt->num_pages);
 
-	while (atomic_long_read(&allocated_pages) > page_pool_size)
-		ttm_pool_shrink();
+	while (atomic_long_read(&allocated_pages) > page_pool_size) {
+		unsigned long diff = page_pool_size - atomic_long_read(&allocated_pages);
+		ttm_pool_shrink(ttm_pool_nid(pool), diff);
+	}
 }
 EXPORT_SYMBOL(ttm_pool_free);
 
@@ -1179,7 +1176,7 @@ static unsigned long ttm_pool_shrinker_scan(struct shrinker *shrink,
 	unsigned long num_freed = 0;
 
 	do
-		num_freed += ttm_pool_shrink();
+		num_freed += ttm_pool_shrink(sc->nid, sc->nr_to_scan);
 	while (num_freed < sc->nr_to_scan &&
 	       atomic_long_read(&allocated_pages));
 
@@ -1319,11 +1316,15 @@ static int ttm_pool_debugfs_shrink_show(struct seq_file *m, void *data)
 		.nr_to_scan = TTM_SHRINKER_BATCH,
 	};
 	unsigned long count;
+	int nid;
 
 	fs_reclaim_acquire(GFP_KERNEL);
-	count = ttm_pool_shrinker_count(mm_shrinker, &sc);
-	seq_printf(m, "%lu/%lu\n", count,
-		   ttm_pool_shrinker_scan(mm_shrinker, &sc));
+	for_each_node(nid) {
+		sc.nid = nid;
+		count = ttm_pool_shrinker_count(mm_shrinker, &sc);
+		seq_printf(m, "%d: %lu/%lu\n", nid, count,
+			   ttm_pool_shrinker_scan(mm_shrinker, &sc));
+	}
 	fs_reclaim_release(GFP_KERNEL);
 
 	return 0;
@@ -1371,7 +1372,7 @@ int ttm_pool_mgr_init(unsigned long num_pages)
 #endif
 #endif
 
-	mm_shrinker = shrinker_alloc(0, "drm-ttm_pool");
+	mm_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE, "drm-ttm_pool");
 	if (!mm_shrinker)
 		return -ENOMEM;
 
-- 
2.49.0