[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240229193935.14197-4-shannon.nelson@amd.com>
Date: Thu, 29 Feb 2024 11:39:26 -0800
From: Shannon Nelson <shannon.nelson@....com>
To: <netdev@...r.kernel.org>, <davem@...emloft.net>, <kuba@...nel.org>,
<edumazet@...gle.com>, <pabeni@...hat.com>
CC: <brett.creeley@....com>, <drivers@...sando.io>, Shannon Nelson
<shannon.nelson@....com>
Subject: [PATCH net-next 03/12] ionic: Shorten a Tx hotpath
From: Brett Creeley <brett.creeley@....com>
Perf was showing some hot spots in ionic_tx_descs_needed()
for TSO traffic. Rework the function to return sooner where
possible.
Signed-off-by: Brett Creeley <brett.creeley@....com>
Signed-off-by: Shannon Nelson <shannon.nelson@....com>
---
drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index dcaa8a4d6ad5..2837f2cc0151 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -1669,7 +1669,7 @@ static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
{
- struct ionic_tx_stats *stats = q_to_tx_stats(q);
+ int nr_frags = skb_shinfo(skb)->nr_frags;
bool too_many_frags = false;
skb_frag_t *frag;
int desc_bufs;
@@ -1685,17 +1685,20 @@ static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
/* Each desc is mss long max, so a descriptor for each gso_seg */
if (skb_is_gso(skb)) {
ndescs = skb_shinfo(skb)->gso_segs;
+ if (!nr_frags)
+ return ndescs;
} else {
ndescs = 1;
- if (skb_shinfo(skb)->nr_frags > q->max_sg_elems) {
+ if (!nr_frags)
+ return ndescs;
+
+ if (unlikely(nr_frags > q->max_sg_elems)) {
too_many_frags = true;
goto linearize;
}
- }
- /* If non-TSO, or no frags to check, we're done */
- if (!skb_is_gso(skb) || !skb_shinfo(skb)->nr_frags)
return ndescs;
+ }
/* We need to scan the skb to be sure that none of the MTU sized
* packets in the TSO will require more sgs per descriptor than we
@@ -1743,6 +1746,8 @@ static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
linearize:
if (too_many_frags) {
+ struct ionic_tx_stats *stats = q_to_tx_stats(q);
+
err = skb_linearize(skb);
if (err)
return err;
--
2.17.1
Powered by blists - more mailing lists