From: Saeed Mahameed <sae...@mellanox.com> Date: Fri, 30 Mar 2018 15:50:08 -0700
> From: Tal Gilboa <ta...@mellanox.com> > > The default TX moderation mode was mistakenly set to CQE based. The > intention was to add a control ability in order to improve some specific > use-cases. In general, we prefer to use EQE based moderation as it gives > much better numbers for the common cases. > > CQE based causes a degradation in the common case since it resets the > moderation timer on CQE generation. This causes an issue when TSO is > well utilized (large TSO sessions). The timer is set to 16us so traffic > of ~64KB TSO sessions per second would mean timer reset (CQE per TSO > session -> long time between CQEs). In this case we quickly reach the > tcp_limit_output_bytes (256KB by default) and cause a halt in TX traffic. > > By setting EQE based moderation we make sure timer would expire after > 16us regardless of the packet rate. > This fixes an up to 40% packet rate and up to 23% bandwidth degradtions. > > Fixes: 0088cbbc4b66 ("net/mlx5e: Enable CQE based moderation on TX CQ") > Signed-off-by: Tal Gilboa <ta...@mellanox.com> > Signed-off-by: Saeed Mahameed <sae...@mellanox.com> Applied and queued up for -stable.