Add statistics to the page pool, providing visibility into its operation.
Callers can provide a location where the stats are stored, otherwise
the page pool will allocate a statistic area.
Signed-off-by: Jonathan Lemon <jonathan.le...@gmail.com>
---
include/net/page_pool.h | 21 +++++++++++++---
net/core/page_pool.c | 55 +++++++++++++++++++++++++++++++++++------
2 files changed, 65 insertions(+), 11 deletions(-)
diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index fc340db42f9a..4f383522b141 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -34,8 +34,11 @@
#include <linux/ptr_ring.h>
#include <linux/dma-direction.h>
-#define PP_FLAG_DMA_MAP 1 /* Should page_pool do the DMA map/unmap */
-#define PP_FLAG_ALL PP_FLAG_DMA_MAP
+#define PP_FLAG_DMA_MAP BIT(0) /* page_pool does the DMA
map/unmap */
+#define PP_FLAG_ALL (PP_FLAG_DMA_MAP)
+
+/* internal flags, not expoed to user */
+#define PP_FLAG_INTERNAL_STATS BIT(8)
/*
* Fast allocation side cache array/stack
@@ -57,6 +60,17 @@
#define PP_ALLOC_POOL_DEFAULT 1024
#define PP_ALLOC_POOL_LIMIT 32768
+struct page_pool_stats {
+ u64 cache_hit;
+ u64 cache_full;
+ u64 cache_empty;
+ u64 ring_produce;
+ u64 ring_consume;
+ u64 ring_return;
+ u64 flush;
+ u64 node_change;
+};
+
struct page_pool_params {
unsigned int flags;
unsigned int order;
@@ -65,6 +79,7 @@ struct page_pool_params {
int nid; /* Numa node id to allocate from pages from */
enum dma_data_direction dma_dir; /* DMA mapping direction */
struct device *dev; /* device, for DMA pre-mapping purposes */
+ struct page_pool_stats *stats; /* pool stats stored externally */
};
struct page_pool {
@@ -230,8 +245,8 @@ static inline bool page_pool_put(struct page_pool *pool)
static inline void page_pool_update_nid(struct page_pool *pool, int new_nid)
{
if (unlikely(pool->p.nid != new_nid)) {
- /* TODO: Add statistics/trace */
pool->p.nid = new_nid;
+ pool->p.stats->node_change++;
}
}
#endif /* _NET_PAGE_POOL_H */
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index f8fedecddb6f..ea6202813584 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -20,9 +20,10 @@
static int page_pool_init(struct page_pool *pool)
{
+ int size;
/* Validate only known flags were used */
- if (pool->p.flags & ~(PP_FLAG_ALL))
+ if (pool->p.flags & ~PP_FLAG_ALL)
return -EINVAL;
if (!pool->p.pool_size)
@@ -40,8 +41,16 @@ static int page_pool_init(struct page_pool *pool)
(pool->p.dma_dir != DMA_BIDIRECTIONAL))
return -EINVAL;
+ if (!pool->p.stats) {
+ size = sizeof(struct page_pool_stats);
+ pool->p.stats = kzalloc_node(size, GFP_KERNEL, pool->p.nid);
+ if (!pool->p.stats)
+ return -ENOMEM;
+ pool->p.flags |= PP_FLAG_INTERNAL_STATS;
+ }
+
if (ptr_ring_init(&pool->ring, pool->p.pool_size, GFP_KERNEL) < 0)
- return -ENOMEM;
+ goto fail;
atomic_set(&pool->pages_state_release_cnt, 0);
@@ -52,6 +61,12 @@ static int page_pool_init(struct page_pool *pool)
get_device(pool->p.dev);
return 0;
+
+fail:
+ if (pool->p.flags & PP_FLAG_INTERNAL_STATS)
+ kfree(pool->p.stats);
+
+ return -ENOMEM;
}
struct page_pool *page_pool_create(const struct page_pool_params *params)
@@ -98,9 +113,11 @@ static struct page *__page_pool_get_cached(struct page_pool
*pool)
if (likely(in_serving_softirq())) {
if (likely(pool->alloc_count)) {
/* Fast-path */
+ pool->p.stats->cache_hit++;
page = pool->alloc_cache[--pool->alloc_count];
return page;
}
+ pool->p.stats->cache_empty++;
refill = true;
}
@@ -113,10 +130,13 @@ static struct page *__page_pool_get_cached(struct
page_pool *pool)
*/
spin_lock(&r->consumer_lock);
page = __ptr_ring_consume(r);
- if (refill)
+ if (refill) {
pool->alloc_count = __ptr_ring_consume_batched(r,
pool->alloc_cache,
PP_ALLOC_CACHE_REFILL);
+ pool->p.stats->ring_consume += pool->alloc_count;
+ }
+ pool->p.stats->ring_consume += !!page;
spin_unlock(&r->consumer_lock);
return page;
}
@@ -266,15 +286,23 @@ static void __page_pool_return_page(struct page_pool
*pool, struct page *page)
static bool __page_pool_recycle_into_ring(struct page_pool *pool,
struct page *page)
{
+ struct ptr_ring *r = &pool->ring;
int ret;
- /* BH protection not needed if current is serving softirq */
if (in_serving_softirq())
- ret = ptr_ring_produce(&pool->ring, page);
+ spin_lock(&r->producer_lock);
else
- ret = ptr_ring_produce_bh(&pool->ring, page);
+ spin_lock_bh(&r->producer_lock);
- return (ret == 0) ? true : false;
+ ret = __ptr_ring_produce(r, page);
+ pool->p.stats->ring_produce++;
+
+ if (in_serving_softirq())
+ spin_unlock(&r->producer_lock);
+ else
+ spin_unlock_bh(&r->producer_lock);
+
+ return ret == 0;
}
/* Only allow direct recycling in special circumstances, into the
@@ -285,8 +313,10 @@ static bool __page_pool_recycle_into_ring(struct page_pool
*pool,
static bool __page_pool_recycle_into_cache(struct page *page,
struct page_pool *pool)
{
- if (unlikely(pool->alloc_count == pool->p.cache_size))
+ if (unlikely(pool->alloc_count == pool->p.cache_size)) {
+ pool->p.stats->cache_full++;
return false;
+ }
/* Caller MUST have verified/know (page_ref_count(page) == 1) */
pool->alloc_cache[pool->alloc_count++] = page;
@@ -343,6 +373,7 @@ EXPORT_SYMBOL(__page_pool_put_page);
static void __page_pool_empty_ring(struct page_pool *pool)
{
struct page *page;
+ int count = 0;
/* Empty recycle ring */
while ((page = ptr_ring_consume_bh(&pool->ring))) {
@@ -351,8 +382,11 @@ static void __page_pool_empty_ring(struct page_pool *pool)
pr_crit("%s() page_pool refcnt %d violation\n",
__func__, page_ref_count(page));
+ count++;
__page_pool_return_page(pool, page);
}
+
+ pool->p.stats->ring_return += count;
}
static void __warn_in_flight(struct page_pool *pool)
@@ -381,6 +415,9 @@ void __page_pool_free(struct page_pool *pool)
if (!__page_pool_safe_to_destroy(pool))
__warn_in_flight(pool);
+ if (pool->p.flags & PP_FLAG_INTERNAL_STATS)
+ kfree(pool->p.stats);
+
ptr_ring_cleanup(&pool->ring, NULL);
if (pool->p.flags & PP_FLAG_DMA_MAP)
@@ -394,6 +431,8 @@ static void page_pool_flush(struct page_pool *pool)
{
struct page *page;
+ pool->p.stats->flush++;
+
/* Empty alloc cache, assume caller made sure this is
* no-longer in use, and page_pool_alloc_pages() cannot be
* called concurrently.
--
2.17.1
