On Wed, 2015-06-03 at 11:10 +0100, Wei Liu wrote: > Xen virtual network driver has higher latency than a physical NIC. > Having only 128K as limit for TSQ introduced 30% regression in guest > throughput. > > This patch raises the limit to 256K. This reduces the regression to 8%. > This buys us more time to work out a proper solution in the long run. > > Signed-off-by: Wei Liu <wei.l...@citrix.com> > Cc: David Miller <da...@davemloft.net> > Cc: Eric Dumazet <eric.duma...@gmail.com> > --- > net/ipv4/tcp_output.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 190538a..eeb59be 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -50,8 +50,8 @@ int sysctl_tcp_retrans_collapse __read_mostly = 1; > */ > int sysctl_tcp_workaround_signed_windows __read_mostly = 0; > > -/* Default TSQ limit of two TSO segments */ > -int sysctl_tcp_limit_output_bytes __read_mostly = 131072; > +/* Default TSQ limit of four TSO segments */ > +int sysctl_tcp_limit_output_bytes __read_mostly = 262144; > > /* This limits the percentage of the congestion window which we > * will allow a single TSO frame to consume. Building TSO frames
Acked-by: Eric Dumazet <eduma...@google.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
