netdev - [PATCH net] pktgen: Fix the inaccurate bps calculation

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Message-ID: <OSZP286MB14047FAFB44F13D76137DFFA95829@OSZP286MB1404.JPNP286.PROD.OUTLOOK.COM>
Date:   Fri,  8 Jul 2022 23:14:01 +0800
From:   gfree.wind@...look.com
To:     davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
        pabeni@...hat.com, netdev@...r.kernel.org
Cc:     gfree.wind@...look.com, Gao Feng <gfree.wind@...il.com>
Subject: [PATCH net] pktgen: Fix the inaccurate bps calculation

From: Gao Feng <gfree.wind@...il.com>

The prior codes use 1000000 as divisor to convert to the Mbps. But it isn't
accurate, because the NIC uses 1024*1024 from bps to Mbps. The result of
the codes is 1.05 times as the real value, even it may cause the result is
more than the nic's physical rate.

Signed-off-by: Gao Feng <gfree.wind@...il.com>
---
 net/core/pktgen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 84b62cd7bc57..e5cd3da63035 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -3305,7 +3305,7 @@ static void show_results(struct pktgen_dev *pkt_dev, int nr_frags)
 	}
 
 	mbps = bps;
-	do_div(mbps, 1000000);
+	do_div(mbps, 1024 * 1024);
 	p += sprintf(p, "  %llupps %lluMb/sec (%llubps) errors: %llu",
 		     (unsigned long long)pps,
 		     (unsigned long long)mbps,
-- 
2.20.1