Commit afb84b62 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by David S. Miller
Browse files

pktgen: add flag NO_TIMESTAMP to disable timestamping 



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: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 05f8461b

net/core/pktgen.c

+16 −3
Original line number Diff line number Diff line
@@ -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
@@ -2685,10 +2693,15 @@ 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);



	if (pkt_dev->flags & F_NO_TIMESTAMP) {

		pgh->tv_sec = 0;

		pgh->tv_usec = 0;

	} else {

		do_gettimeofday(&timestamp);

		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,

					struct pktgen_dev *pkt_dev,

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