On Wed, 2015-04-15 at 18:41 +0100, George Dunlap wrote: > So you'd be OK with a patch like this? (With perhaps a better changelog?) > > -George > > --- > TSQ: Raise default static TSQ limit > > A new dynamic TSQ limit was introduced in c/s 605ad7f18 based on the > size of actual packets and the amount of data being transmitted. > Raise the default static limit to allow that new limit to actually > come into effect. > > This fixes a regression where NICs with large transmit completion > times (such as xennet) had a 30% hit unless the user manually tweaked > the value in /proc. > > Signed-off-by: George Dunlap <george.dun...@eu.citrix.com> > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 1db253e..8ad7cdf 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; > +/* Static TSQ limit. A more dynamic limit is calculated in > tcp_write_xmit. */ > +int sysctl_tcp_limit_output_bytes __read_mostly = 1048576; > > /* This limits the percentage of the congestion window which we > * will allow a single TSO frame to consume. Building TSO frames >
Have you tested this patch on a NIC without GSO/TSO ? This would allow more than 500 packets for a single flow. Hello bufferbloat. So my answer to this patch is a no. -- 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
