From afb84b6261841f8ab387e267e748236fa805bea0 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 28 Aug 2014 18:14:47 +0200 Subject: [PATCH] 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: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- net/core/pktgen.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 5b36a9428c59..21cb4839bc97 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, -- 2.30.2