On Sat, Jun 08, 2013 at 02:17:41PM +0800, Jason Wang wrote: > Commit 54f968d6efdbf7dec36faa44fc11f01b0e4d1990 > (tuntap: move socket to tun_file) forgets to set SOCK_ZEROCOPY flag, which > will > prevent vhost_net from doing zercopy w/ tap. This patch fixes this by setting > it during file open. > > Cc: Michael S. Tsirkin <m...@redhat.com> > Signed-off-by: Jason Wang <jasow...@redhat.com>
I see, and this explains the perf regression we are seeing with 3.9. Acked-by: Michael S. Tsirkin <m...@redhat.com> and I think this should go into stable as well. > --- > drivers/net/tun.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index f042b03..d2ddd6d 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -2155,6 +2155,8 @@ static int tun_chr_open(struct inode *inode, struct > file * file) > set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags); > INIT_LIST_HEAD(&tfile->next); > > + sock_set_flag(&tfile->sk, SOCK_ZEROCOPY); > + > return 0; > } > > -- > 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
