On Thu, Mar 31, 2016 at 3:28 PM, Stefan Hajnoczi <stefa...@gmail.com> wrote:
> On Mon, Mar 28, 2016 at 06:04:11PM +0530, Pooja Dhannawat wrote: > > nc_sendv_compat has a huge stack usage of 69680 bytes approx. > > Moving large arrays to heap to reduce stack usage. > > > > Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com> > > Signed-off-by: Pooja Dhannawat <dhannawatpoo...@gmail.com> > > --- > > net/net.c | 13 +++++++++---- > > 1 file changed, 9 insertions(+), 4 deletions(-) > > > > diff --git a/net/net.c b/net/net.c > > index b0c832e..663da13 100644 > > --- a/net/net.c > > +++ b/net/net.c > > @@ -709,23 +709,28 @@ ssize_t qemu_send_packet_raw(NetClientState *nc, > const uint8_t *buf, int size) > > static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec > *iov, > > int iovcnt, unsigned flags) > > { > > - uint8_t buf[NET_BUFSIZE]; > > + uint8_t *buf = NULL; > > uint8_t *buffer; > > size_t offset; > > + ssize_t ret; > > > > if (iovcnt == 1) { > > buffer = iov[0].iov_base; > > offset = iov[0].iov_len; > > } else { > > + buf = g_new(uint8_t, NET_BUFSIZE); > > buffer = buf; > > - offset = iov_to_buf(iov, iovcnt, 0, buf, sizeof(buf)); > > + offset = iov_to_buf(iov, iovcnt, 0, buf, NET_BUFSIZE); > > } > > > > if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) { > > - return nc->info->receive_raw(nc, buffer, offset); > > + ret = nc->info->receive_raw(nc, buffer, offset); > > } else { > > - return nc->info->receive(nc, buffer, offset); > > + ret = nc->info->receive(nc, buffer, offset); > > } > > + > > + g_free(buf); > > + return ret; > > } > > > > ssize_t qemu_deliver_packet_iov(NetClientState *sender, > > -- > > 2.5.0 > > CCing Jason Wang, net subsystem maintainer. Please use > scripts/get_maintainer.pl to find the right people to CC in future > patches. > > Yes, I am sorry about that. Fam also pointed out this thing but I forgot this time also. I will keep that mind from onwards. > We may also want to keep a smaller stack buffer so that reasonably-sized > packets (e.g. up to 2 KB) can be send without the performance cost of > g_malloc(). >