Re: [PATCH net-next v4 0/4] Add support to do threaded napi busy poll

[Joe Damato <jdamato@fastly.com>]

On Wed, Mar 26, 2025 at 02:57:37PM -0700, Stanislav Fomichev wrote:
> On 03/26, Samiullah Khawaja wrote:
> > On Tue, Mar 25, 2025 at 10:47 AM Martin Karsten <mkarsten@uwaterloo.ca> wrote:
> > >
> > > On 2025-03-25 12:40, Samiullah Khawaja wrote:
> > > > On Sun, Mar 23, 2025 at 7:38 PM Martin Karsten <mkarsten@uwaterloo.ca> wrote:
> > > >>
> > > >> On 2025-03-20 22:15, Samiullah Khawaja wrote:

> > > > Nice catch. It seems a recent change broke the busy polling for AF_XDP
> > > > and there was a fix for the XDP_ZEROCOPY but the XDP_COPY remained
> > > > broken and seems in my experiments I didn't pick that up. During my
> > > > experimentation I confirmed that all experiment modes are invoking the
> > > > busypoll and not going through softirqs. I confirmed this through perf
> > > > traces. I sent out a fix for XDP_COPY busy polling here in the link
> > > > below. I will resent this for the net since the original commit has
> > > > already landed in 6.13.
> > > > https://lore.kernel.org/netdev/CAAywjhSEjaSgt7fCoiqJiMufGOi=oxa164_vTfk+3P43H60qwQ@mail.gmail.com/T/#t
> 
> In general, when sending the patches and numbers, try running everything
> against the latest net-next. Otherwise, it is very confusing to reason
> about..

I had mentioned in my previous review, but worth mentioning again...
using --base=auto when using format-patch to generate the base
commit SHA would be really useful to potentially help avoid this
problem.