[dpdk-users] Does vmxnet3 PMD supports LSC=1 ?

[Thomas Monjalon]

+Cc Yong Wang, maintainer of this PMD.

14/01/2021 18:30, madhukar mythri:
> Hi,
> 
> Does vmxnet3 PMD support LSC=1(i.e with interrupt mode) for link changes ?
> 
> When i enable LSC=1 the functionality works fine, but, when pumping traffic
> i'm seeing increasing in CPU load on some cores which is running
> "eal-intr-thread" epoll_wait() function for more CPU-time.
> 
> Actually, interrupt should come only when Link changes, but, we are seeing
> interrupt for each incoming Rx-packet and also a lot of spurious interrupts.
> =============
> ~ # cat /proc/interrupts |grep igb
>  58:    1254293          0          0          0   PCI-MSI 1572864-edge
>  igb_uio
>  59:    1278105          0          0          0   PCI-MSI 5767168-edge
>  igb_uio
> ~ # cat /proc/irq/58/spurious
> count 98035
> unhandled 0
> last_unhandled 0 ms
> ~ #
> ==============
> 
> Does anyone tried LSC=1 in vmxnet3 PMD based apps and faced similar issues
> ? If so, please let me know.
> 
> Tried with DPDK-18.11, DPDK-19.11 and DPDK-20.05.
> 
> Thanks,
> Madhukar.