netdev - [PATCH net-next] ynl: samples: fix recycling rate calculation

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Message-ID: <20240307221122.2094511-1-kuba@kernel.org>
Date: Thu,  7 Mar 2024 14:11:22 -0800
From: Jakub Kicinski <kuba@...nel.org>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org,
	edumazet@...gle.com,
	pabeni@...hat.com,
	Jakub Kicinski <kuba@...nel.org>,
	hawk@...nel.org
Subject: [PATCH net-next] ynl: samples: fix recycling rate calculation

Running the page-pool sample on production machines under moderate
networking load shows recycling rate higher than 100%:

$ page-pool
    eth0[2]	page pools: 14 (zombies: 0)
		refs: 89088 bytes: 364904448 (refs: 0 bytes: 0)
		recycling: 100.3% (alloc: 1392:2290247724 recycle: 469289484:1828235386)

Note that outstanding refs (89088) == slow alloc * cache size (1392 * 64)
which means this machine is recycling page pool pages perfectly, not
a single page has been released.

The extra 0.3% is because sample ignores allocations from the ptr_ring.
Treat those the same as alloc_fast, the ring vs cache alloc is
already captured accurately enough by recycling stats.

With the fix:

$ page-pool
    eth0[2]	page pools: 14 (zombies: 0)
		refs: 89088 bytes: 364904448 (refs: 0 bytes: 0)
		recycling: 100.0% (alloc: 1392:2331141604 recycle: 473625579:1857460661)

Signed-off-by: Jakub Kicinski <kuba@...nel.org>
---
CC: hawk@...nel.org
---
 tools/net/ynl/samples/page-pool.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/net/ynl/samples/page-pool.c b/tools/net/ynl/samples/page-pool.c
index 098b5190d0e5..332f281ee5cb 100644
--- a/tools/net/ynl/samples/page-pool.c
+++ b/tools/net/ynl/samples/page-pool.c
@@ -95,6 +95,8 @@ int main(int argc, char **argv)
 
 		if (pp->_present.alloc_fast)
 			s->alloc_fast += pp->alloc_fast;
+		if (pp->_present.alloc_refill)
+			s->alloc_fast += pp->alloc_refill;
 		if (pp->_present.alloc_slow)
 			s->alloc_slow += pp->alloc_slow;
 		if (pp->_present.recycle_ring)
-- 
2.44.0