diff mbox series

[net-next,4/6] net: page_pool: Add stat tracking empty ring

Message ID 1643237300-44904-5-git-send-email-jdamato@fastly.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net: page_pool: Add page_pool stat counters | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5991 this patch: 5991
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 882 this patch: 882
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 6142 this patch: 6142
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 44 lines checked
netdev/kdoc success Errors and warnings before: 2 this patch: 2
netdev/source_inline success Was 0 now: 0

Commit Message

Joe Damato Jan. 26, 2022, 10:48 p.m. UTC 
Add a stat tracking when the ptr ring is empty. A static inline wrapper
function is exposed to access this stat.

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 include/net/page_pool.h | 15 +++++++++++++++
 net/core/page_pool.c    |  4 +++-
 2 files changed, 18 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index b024197..92edf8e 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -84,6 +84,10 @@  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;
 };
 
@@ -212,6 +216,12 @@  static inline u64 page_pool_stats_get_slow_high_order(struct page_pool *pool)
 {
 	return pool->ps.alloc.slow_high_order;
 }
+
+static inline u64 page_pool_stats_get_empty(struct page_pool *pool)
+{
+	return pool->ps.alloc.empty;
+}
+
 #else
 static inline void page_pool_destroy(struct page_pool *pool)
 {
@@ -246,6 +256,11 @@  static inline u64 page_pool_stats_get_slow_high_order(struct page_pool *pool)
 {
 	return 0;
 }
+
+static inline u64 page_pool_stats_get_empty(struct page_pool *pool)
+{
+	return 0;
+}
 #endif
 
 void page_pool_put_page(struct page_pool *pool, struct page *page,
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 3a4b912..0de9d58 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -117,8 +117,10 @@  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)) {
+		pool->ps.alloc.empty++;
 		return NULL;
+	}
 
 	/* Softirq guarantee CPU and thus NUMA node is stable. This,
 	 * assumes CPU refilling driver RX-ring will also run RX-NAPI.