[PATCH 2/2] drm/ttm: use gpu mm stats to track gpu memory allocations.

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

This uses the newly introduced per-node gpu tracking stats,
to track GPU memory allocated via TTM and reclaimable memory in
the TTM page pools.

These stats will be useful later for system information and
later when mem cgroups are integrated.

Cc: Christian Koenig <christian.koenig at amd.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: linux-mm at kvack.org
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/ttm/ttm_pool.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index c2ea865be657..ccc3b9a13e9e 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -130,6 +130,16 @@ static struct list_head shrinker_list;
 static struct shrinker *mm_shrinker;
 static DECLARE_RWSEM(pool_shrink_rwsem);
 
+/* helper to get a current valid node id from a pool */
+static int ttm_pool_nid(struct ttm_pool *pool) {
+	int nid = NUMA_NO_NODE;
+	if (pool)
+		nid = pool->nid;
+	if (nid == NUMA_NO_NODE)
+		nid = numa_node_id();
+	return nid;
+}
+
 /* Allocate pages of size 1 << order with the given gfp_flags */
 static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
 					unsigned int order)
@@ -149,8 +159,10 @@ static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
 
 	if (!pool->use_dma_alloc) {
 		p = alloc_pages_node(pool->nid, gfp_flags, order);
-		if (p)
+		if (p) {
 			p->private = order;
+			mod_node_page_state(NODE_DATA(ttm_pool_nid(pool)), NR_GPU_ACTIVE, (1 << order));
+		}
 		return p;
 	}
 
@@ -201,6 +213,7 @@ static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
 
 	if (!pool || !pool->use_dma_alloc) {
 		__free_pages(p, order);
+		mod_node_page_state(NODE_DATA(ttm_pool_nid(pool)), NR_GPU_ACTIVE, -(1 << order));
 		return;
 	}
 
@@ -275,6 +288,7 @@ static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
 static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
 {
 	unsigned int i, num_pages = 1 << pt->order;
+	int nid = ttm_pool_nid(pt->pool);
 
 	for (i = 0; i < num_pages; ++i) {
 		if (PageHighMem(p))
@@ -287,17 +301,23 @@ static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
 	list_add(&p->lru, &pt->pages);
 	spin_unlock(&pt->lock);
 	atomic_long_add(1 << pt->order, &allocated_pages);
+
+	mod_node_page_state(NODE_DATA(nid), NR_GPU_ACTIVE, -(1 << pt->order));
+	mod_node_page_state(NODE_DATA(nid), NR_GPU_RECLAIM, (1 << pt->order));
 }
 
 /* Take pages from a specific pool_type, return NULL when nothing available */
 static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
 {
 	struct page *p;
+	int nid = ttm_pool_nid(pt->pool);
 
 	spin_lock(&pt->lock);
 	p = list_first_entry_or_null(&pt->pages, typeof(*p), lru);
 	if (p) {
 		atomic_long_sub(1 << pt->order, &allocated_pages);
+		mod_node_page_state(NODE_DATA(nid), NR_GPU_ACTIVE, (1 << pt->order));
+		mod_node_page_state(NODE_DATA(nid), NR_GPU_RECLAIM, -(1 << pt->order));
 		list_del(&p->lru);
 	}
 	spin_unlock(&pt->lock);
-- 
2.49.0