From: "Michał Mirosław" <mirqus@gmail.com>
To: Keith Wiles <keith.wiles@intel.com>
Cc: dev@dpdk.org, pmatilai@redhat.com, yuanhan.liu@linux.intel.com
Subject: Re: [dpdk-dev] [PATCH v4] drivers/net:new PMD using tun/tap host interface
Date: Tue, 11 Oct 2016 13:30:54 +0200 [thread overview]
Message-ID: <CAHXqBFJsMsHqKD-dsS=DUg5DXwcjBc9T6=wuHft5utO3cgj0Ug@mail.gmail.com> (raw)
In-Reply-To: <1475592311-25749-1-git-send-email-keith.wiles@intel.com>
2016-10-04 16:45 GMT+02:00, Keith Wiles <keith.wiles@intel.com>:
> The rte_eth_tap.c PMD creates a device using TUN/TAP interfaces
> on the local host. The PMD allows for DPDK and the host to
> communicate using a raw device interface on the host and in
> the DPDK application. The device created is a Tap device with
> a L2 packet header.
[...]
> +static uint16_t
> +pmd_rx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> +{
> + int len, n;
> + struct rte_mbuf *mbuf;
> + struct rx_queue *rxq = queue;
> + struct pollfd pfd;
> + uint16_t num_rx;
> + unsigned long num_rx_bytes = 0;
> +
> + pfd.events = POLLIN;
> + pfd.fd = rxq->fd;
> + for (num_rx = 0; num_rx < nb_pkts; ) {
> + n = poll(&pfd, 1, 0);
> +
> + if (n <= 0)
> + break;
> +
Considering that syscalls are rather expensive, it would be cheaper to
allocate an mbuf here and free it when read() returns -1 instead of
calling poll() to check whether a packet is waiting. This way you
save a syscall per packet and replace one syscall with one mbuf free
per poll.
Best Regards,
Michał Mirosław
next prev parent reply other threads:[~2016-10-11 11:30 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-15 14:10 [dpdk-dev] [PATCH 1/3] " Keith Wiles
2016-09-15 14:10 ` [dpdk-dev] [PATCH 2/3] docs:tun/tap PMD information Keith Wiles
2016-09-15 14:13 ` Wiles, Keith
2016-09-15 14:15 ` Wiles, Keith
2016-09-21 2:00 ` [dpdk-dev] [PATCH v3] drivers/net:new PMD using tun/tap host interface Keith Wiles
2016-10-04 14:45 ` [dpdk-dev] [PATCH v4] " Keith Wiles
2016-10-11 9:40 ` Ferruh Yigit
2016-10-11 11:30 ` Michał Mirosław [this message]
2016-10-11 20:56 ` Wiles, Keith
2016-10-12 8:14 ` Michał Mirosław
2016-10-11 11:49 ` Ferruh Yigit
2016-10-11 21:07 ` Wiles, Keith
2016-10-11 12:28 ` Ferruh Yigit
2016-10-11 20:57 ` Wiles, Keith
2016-10-11 21:51 ` [dpdk-dev] [PATCH v5] " Keith Wiles
2016-10-12 14:56 ` Ferruh Yigit
2016-10-12 18:19 ` Wiles, Keith
2016-10-12 19:57 ` Wiles, Keith
2016-10-12 20:54 ` [dpdk-dev] [PATCH v6] " Keith Wiles
2016-10-13 14:41 ` Ferruh Yigit
2016-10-13 15:36 ` [dpdk-dev] [PATCH v7] " Keith Wiles
2016-10-13 16:11 ` [dpdk-dev] [PATCH v8] " Keith Wiles
2016-10-13 16:33 ` Mcnamara, John
2016-10-13 22:03 ` [dpdk-dev] [PATCH v9] " Keith Wiles
2016-10-14 6:41 ` Mcnamara, John
2016-10-14 9:39 ` Ferruh Yigit
2016-11-21 12:56 ` Ferruh Yigit
2016-11-25 19:38 ` Aws Ismail
2016-11-29 21:36 ` Aws Ismail
2016-11-29 22:16 ` Wiles, Keith
2016-12-07 19:38 ` [dpdk-dev] [PATCH v10] drivers/net:new TUN/TAP device PMD Keith Wiles
2016-12-07 20:15 ` Aws Ismail
2016-12-09 18:16 ` Ferruh Yigit
2016-12-09 19:05 ` [dpdk-dev] [PATCH v11] " Keith Wiles
2016-12-12 12:39 ` Vasily Philipov
2016-12-12 14:24 ` [dpdk-dev] [PATCH v12] net/tap: new " Keith Wiles
2016-12-12 14:38 ` Keith Wiles
2016-12-12 19:13 ` Marc
2016-12-12 21:09 ` Wiles, Keith
2016-12-13 13:54 ` Ferruh Yigit
2017-01-20 12:14 ` Ferruh Yigit
2017-01-20 14:25 ` [dpdk-dev] [PATCH] net/tap: fix IFF_MULTI_QUEUE in older kernels not found Keith Wiles
2017-01-20 14:30 ` Keith Wiles
2017-01-20 16:11 ` Ferruh Yigit
2017-01-20 17:37 ` Thomas Monjalon
2016-09-15 14:10 ` [dpdk-dev] [PATCH 3/3] drivers/net:build support for new tap device driver Keith Wiles
2016-09-16 7:36 ` Panu Matilainen
2016-09-16 14:46 ` Wiles, Keith
2016-09-16 16:22 ` [dpdk-dev] [PATCH v2] drivers/net:new PMD using tun/tap host interface Keith Wiles
2016-09-18 13:25 ` Yuanhan Liu
2016-09-18 16:20 ` Wiles, Keith
2016-09-19 0:29 ` Yuanhan Liu
2016-09-19 15:56 ` Wiles, Keith
2016-09-20 3:54 ` Yuanhan Liu
2016-09-20 4:05 ` Yuanhan Liu
2016-09-21 1:32 ` Wiles, Keith
2016-09-21 2:13 ` Yuanhan Liu
2016-09-21 8:24 ` Thomas Monjalon
2016-09-21 23:55 ` Wiles, Keith
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