From: Jesper Dangaard Brouer <brouer@redhat•com>
To: Jesper Dangaard Brouer <brouer@redhat•com>,
"David S. Miller" <davem@davemloft•net>,
netdev@vger•kernel.org
Cc: Ben Greear <greearb@candelatech•com>, Robert Olsson <robert@herjulf•se>
Subject: [net-next PATCH] pktgen: add flag NO_TIMESTAMP to disable timestamping
Date: Thu, 28 Aug 2014 18:14:47 +0200 [thread overview]
Message-ID: <20140828161447.6652.59388.stgit@dragon> (raw)
Then testing the TX limits of the stack, then it is useful to
be-able to disable the do_gettimeofday() timetamping on every packet.
This implements a pktgen flag NO_TIMESTAMP which will disable this
call to do_gettimeofday().
The performance change on (my system E5-2695) with skb_clone=0, goes
from TX 2,423,751 pps to 2,567,165 pps with flag NO_TIMESTAMP. Thus,
the cost of do_gettimeofday() or saving is approx 23 nanosec.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat•com>
---
net/core/pktgen.c | 19 ++++++++++++++++---
1 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 83e2b4b..d9acc16 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -202,6 +202,7 @@
#define F_QUEUE_MAP_CPU (1<<14) /* queue map mirrors smp_processor_id() */
#define F_NODE (1<<15) /* Node memory alloc*/
#define F_UDPCSUM (1<<16) /* Include UDP checksum */
+#define F_NO_TIMESTAMP (1<<17) /* Don't timestamp packets (default TS) */
/* Thread control flag bits */
#define T_STOP (1<<0) /* Stop run */
@@ -638,6 +639,9 @@ static int pktgen_if_show(struct seq_file *seq, void *v)
if (pkt_dev->flags & F_UDPCSUM)
seq_puts(seq, "UDPCSUM ");
+ if (pkt_dev->flags & F_NO_TIMESTAMP)
+ seq_puts(seq, "NO_TIMESTAMP ");
+
if (pkt_dev->flags & F_MPLS_RND)
seq_puts(seq, "MPLS_RND ");
@@ -1243,6 +1247,9 @@ static ssize_t pktgen_if_write(struct file *file,
else if (strcmp(f, "!UDPCSUM") == 0)
pkt_dev->flags &= ~F_UDPCSUM;
+ else if (strcmp(f, "NO_TIMESTAMP") == 0)
+ pkt_dev->flags |= F_NO_TIMESTAMP;
+
else {
sprintf(pg_result,
"Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
@@ -1251,6 +1258,7 @@ static ssize_t pktgen_if_write(struct file *file,
"MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, "
"MPLS_RND, VID_RND, SVID_RND, FLOW_SEQ, "
"QUEUE_MAP_RND, QUEUE_MAP_CPU, UDPCSUM, "
+ "NO_TIMESTAMP, "
#ifdef CONFIG_XFRM
"IPSEC, "
#endif
@@ -2685,9 +2693,14 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb,
pgh->pgh_magic = htonl(PKTGEN_MAGIC);
pgh->seq_num = htonl(pkt_dev->seq_num);
- do_gettimeofday(×tamp);
- pgh->tv_sec = htonl(timestamp.tv_sec);
- pgh->tv_usec = htonl(timestamp.tv_usec);
+ if (pkt_dev->flags & F_NO_TIMESTAMP) {
+ pgh->tv_sec = 0;
+ pgh->tv_usec = 0;
+ } else {
+ do_gettimeofday(×tamp);
+ pgh->tv_sec = htonl(timestamp.tv_sec);
+ pgh->tv_usec = htonl(timestamp.tv_usec);
+ }
}
static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
next reply other threads:[~2014-08-28 16:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 16:14 Jesper Dangaard Brouer [this message]
2014-08-29 16:17 ` [net-next PATCH] pktgen: add flag NO_TIMESTAMP to disable timestamping Eric Dumazet
2014-08-29 19:02 ` Jesper Dangaard Brouer
2014-09-02 1:07 ` David Miller
2015-04-01 16:48 ` Ben Greear
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