[openib-general] [PATCH] IB/ipoib: NAPI

[Michael S. Tsirkin]

Quoting r. Shirley Ma <xma at us.ibm.com>:
> Subject: Re: [PATCH] IB/ipoib: NAPI
> 
> We did some touch test on ehca driver, we saw performance drop somehow.

Hmm, it seems ehca still defers the completion event to a tasklet.  It always
seemed weird to me.  So that could be the reason - with NAPI you now get 2
tasklet schedules, as you are actually doing part of what NAPI does, inside the
low level driver.  Try ripping that out and calling the event handler directly,
and see what it does to performance with NAPI.

> I strongly recommand NAPI as a configurable option in ipoib. So customers can turn on/off based on their configurations.

I still hope ehca NAPI performance can be fixed. But if not, maybe we should
have the low level driver set a disable_napi flag rather than have users play
with module options.

-- 
MST