[dpdk-dev,1/2] net/tap: remove redundant syscall on Tx
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Commit Message
Polling the Tx queue file descriptor before writing to it is not mandatory
since it is configured as non-blocking.
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Pascal Mazon <pascal.mazon@6wind.com>
---
drivers/net/tap/rte_eth_tap.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
Comments
> On Mar 14, 2017, at 8:51 PM, Adrien Mazarguil <adrien.mazarguil@6wind.com> wrote:
>
> Polling the Tx queue file descriptor before writing to it is not mandatory
> since it is configured as non-blocking.
>
> Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> Acked-by: Pascal Mazon <pascal.mazon@6wind.com>
Acked-by: Keith Wiles <keith.wiles@intel.com>
> ---
> drivers/net/tap/rte_eth_tap.c | 26 ++++++++------------------
> 1 file changed, 8 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index efc4426..c757a7c 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -43,7 +43,6 @@
> #include <sys/ioctl.h>
> #include <sys/mman.h>
> #include <unistd.h>
> -#include <poll.h>
> #include <arpa/inet.h>
> #include <linux/if.h>
> #include <linux/if_tun.h>
> @@ -242,7 +241,6 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> {
> struct rte_mbuf *mbuf;
> struct tx_queue *txq = queue;
> - struct pollfd pfd;
> uint16_t num_tx = 0;
> unsigned long num_tx_bytes = 0;
> int i, n;
> @@ -250,26 +248,18 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> if (unlikely(nb_pkts == 0))
> return 0;
>
> - pfd.events = POLLOUT;
> - pfd.fd = txq->fd;
> for (i = 0; i < nb_pkts; i++) {
> - n = poll(&pfd, 1, 0);
> -
> + /* copy the tx frame data */
> + mbuf = bufs[num_tx];
> + n = write(txq->fd,
> + rte_pktmbuf_mtod(mbuf, void *),
> + rte_pktmbuf_pkt_len(mbuf));
> if (n <= 0)
> break;
>
> - if (pfd.revents & POLLOUT) {
> - /* copy the tx frame data */
> - mbuf = bufs[num_tx];
> - n = write(pfd.fd, rte_pktmbuf_mtod(mbuf, void*),
> - rte_pktmbuf_pkt_len(mbuf));
> - if (n <= 0)
> - break;
> -
> - num_tx++;
> - num_tx_bytes += mbuf->pkt_len;
> - rte_pktmbuf_free(mbuf);
> - }
> + num_tx++;
> + num_tx_bytes += mbuf->pkt_len;
> + rte_pktmbuf_free(mbuf);
> }
>
> txq->stats.opackets += num_tx;
> --
> 2.1.4
>
Regards,
Keith
On 3/14/2017 1:52 PM, Wiles, Keith wrote:
>
>> On Mar 14, 2017, at 8:51 PM, Adrien Mazarguil <adrien.mazarguil@6wind.com> wrote:
>>
>> Polling the Tx queue file descriptor before writing to it is not mandatory
>> since it is configured as non-blocking.
>>
>> Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
>> Acked-by: Pascal Mazon <pascal.mazon@6wind.com>
>
> Acked-by: Keith Wiles <keith.wiles@intel.com>
Series applied to dpdk-next-net/master, thanks.
@@ -43,7 +43,6 @@
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
-#include <poll.h>
#include <arpa/inet.h>
#include <linux/if.h>
#include <linux/if_tun.h>
@@ -242,7 +241,6 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
{
struct rte_mbuf *mbuf;
struct tx_queue *txq = queue;
- struct pollfd pfd;
uint16_t num_tx = 0;
unsigned long num_tx_bytes = 0;
int i, n;
@@ -250,26 +248,18 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
if (unlikely(nb_pkts == 0))
return 0;
- pfd.events = POLLOUT;
- pfd.fd = txq->fd;
for (i = 0; i < nb_pkts; i++) {
- n = poll(&pfd, 1, 0);
-
+ /* copy the tx frame data */
+ mbuf = bufs[num_tx];
+ n = write(txq->fd,
+ rte_pktmbuf_mtod(mbuf, void *),
+ rte_pktmbuf_pkt_len(mbuf));
if (n <= 0)
break;
- if (pfd.revents & POLLOUT) {
- /* copy the tx frame data */
- mbuf = bufs[num_tx];
- n = write(pfd.fd, rte_pktmbuf_mtod(mbuf, void*),
- rte_pktmbuf_pkt_len(mbuf));
- if (n <= 0)
- break;
-
- num_tx++;
- num_tx_bytes += mbuf->pkt_len;
- rte_pktmbuf_free(mbuf);
- }
+ num_tx++;
+ num_tx_bytes += mbuf->pkt_len;
+ rte_pktmbuf_free(mbuf);
}
txq->stats.opackets += num_tx;