> -----Original Message----- > From: Erni Sri Satya Vennela <ernis@xxxxxxxxxxxxxxxxxxx> > Sent: Wednesday, August 14, 2024 12:59 PM > To: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx>; wei.liu@xxxxxxxxxx; Dexuan Cui > <decui@xxxxxxxxxxxxx>; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; > kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; linux-hyperv@xxxxxxxxxxxxxxx; > netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Cc: Erni Sri Satya Vennela <ernis@xxxxxxxxxxxxx>; Erni Sri Satya Vennela > <ernis@xxxxxxxxxxxxxxxxxxx> > Subject: [PATCH v2] net: netvsc: Update default VMBus channels > > Change VMBus channels macro (VRSS_CHANNEL_DEFAULT) in > Linux netvsc from 8 to 16 to align with Azure Windows VM > and improve networking throughput. > > For VMs having less than 16 vCPUS, the channels depend > on number of vCPUs. Between 16 to 32 vCPUs, the channels > default to VRSS_CHANNEL_DEFAULT. For greater than 32 vCPUs, > set the channels to number of physical cores / 2 as a way > to optimize CPU resource utilization and scale for high-end > processors with many cores. > Maximum number of channels are by default set to 64. > > Based on this change the subchannel creation would change as follows: > > ------------------------------------------------------------- > |No. of vCPU |dev_info->num_chn |subchannel created | > ------------------------------------------------------------- > | 0-16 | 16 | vCPU | > | >16 & <=32 | 16 | 16 | > | >32 & <=128 | vCPU/2 | vCPU/2 | > | >128 | vCPU/2 | 64 | > ------------------------------------------------------------- > > Performance tests showed significant improvement in throughput: > - 0.54% for 16 vCPUs > - 0.83% for 32 vCPUs > - 1.76% for 48 vCPUs > - 10.35% for 64 vCPUs > - 13.47% for 96 vCPUs > > Signed-off-by: Erni Sri Satya Vennela <ernis@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Thanks.
