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Revert "tuntap: add missing xdp flush"

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This reverts commit 762c330d67. The
reason is we try to batch packets for devmap which causes calling
xdp_do_flush() in the process context. Simply disabling preemption
may not work since process may move among processors which lead
xdp_do_flush() to miss some flushes on some processors.

So simply revert the patch, a follow-up patch will add the xdp flush
correctly.

Reported-by: Christoffer Dall <christoffer.dall@linaro.org>
Fixes: 762c330d67 ("tuntap: add missing xdp flush")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2018-02-24 11:32:24 +08:00 committed by David S. Miller
parent 0c5661ecc5
commit f249be4d2c
1 changed files with 0 additions and 15 deletions
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15
drivers/net/tun.c
View File

@ -181,7 +181,6 @@ struct tun_file {
struct tun_struct *detached;
struct ptr_ring tx_ring;
struct xdp_rxq_info xdp_rxq;
int xdp_pending_pkts;
};
struct tun_flow_entry {
@ -1662,7 +1661,6 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
case XDP_REDIRECT:
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
++tfile->xdp_pending_pkts;
err = xdp_do_redirect(tun->dev, &xdp, xdp_prog);
if (err)
goto err_redirect;
@ -1984,11 +1982,6 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
result = tun_get_user(tun, tfile, NULL, from,
file->f_flags & O_NONBLOCK, false);
if (tfile->xdp_pending_pkts) {
tfile->xdp_pending_pkts = 0;
xdp_do_flush_map();
}
tun_put(tun);
return result;
}
@ -2325,13 +2318,6 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
m->msg_flags & MSG_DONTWAIT,
m->msg_flags & MSG_MORE);
if (tfile->xdp_pending_pkts >= NAPI_POLL_WEIGHT ||
!(m->msg_flags & MSG_MORE)) {
tfile->xdp_pending_pkts = 0;
xdp_do_flush_map();
}
tun_put(tun);
return ret;
}
@ -3163,7 +3149,6 @@ static int tun_chr_open(struct inode *inode, struct file * file)
sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
memset(&tfile->tx_ring, 0, sizeof(tfile->tx_ring));
tfile->xdp_pending_pkts = 0;
return 0;
}