diff mbox series

[net-next,v3,07/10] page_pool: Add stat tracking empty ring

Message ID 1643764336-63864-8-git-send-email-jdamato@fastly.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series 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: 5979 this patch: 5979
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 879 this patch: 879
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: 6130 this patch: 6130
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Joe Damato Feb. 2, 2022, 1:12 a.m. UTC 
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(-)
diff mbox series

Patch

diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index f59b8a9..ed2bc73 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -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;
 };
 
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 24306d6..9d20b12 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -131,8 +131,10 @@  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)) {
+		page_pool_stat_alloc_inc(empty);
 		return NULL;
+	}
 
 	/* Softirq guarantee CPU and thus NUMA node is stable. This,
 	 * assumes CPU refilling driver RX-ring will also run RX-NAPI.