@@ -146,6 +146,9 @@ struct page_pool_stats {
u64 fast; /* fast path allocations */
u64 slow; /* slow-path order 0 allocations */
u64 slow_high_order; /* slow-path high order allocations */
+ u64 empty; /* failed refills due to empty ptr ring, forcing
+ * slow path allocation
+ */
} alloc;
};
#endif
@@ -136,8 +136,10 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
int pref_nid; /* preferred NUMA node */
/* Quicker fallback, avoid locks when ring is empty */
- if (__ptr_ring_empty(r))
+ if (__ptr_ring_empty(r)) {
+ this_cpu_inc_alloc_stat(pool, empty);
return NULL;
+ }
/* Softirq guarantee CPU and thus NUMA node is stable. This,
* assumes CPU refilling driver RX-ring will also run RX-NAPI.
Add a stat tracking when the ptr ring is empty. When this occurs, the cache could not be refilled and a slow path allocation was forced. Signed-off-by: Joe Damato <jdamato@fastly.com> --- include/net/page_pool.h | 3 +++ net/core/page_pool.c | 4 +++- 2 files changed, 6 insertions(+), 1 deletion(-)