ixgbe & if_igb RX ring locking

[Jack Vogel]

On Mon, Oct 15, 2012 at 9:58 AM, Gleb Smirnoff <glebius at freebsd.org> wrote:

> On Mon, Oct 15, 2012 at 09:39:24AM -0700, Jack Vogel wrote:
> J> > To me this unlock/lock looks like a legacy from times, when the driver
> J> > had a single mutex for both TX and RX parts.
> J> >
> J> > And removing this re-locking in foo_rxeof() was one of the aims for
> J> > separate
> J> > TX/RX locking.
> J> >
> J> > Really, lurking through history shows that once driver had split its
> J> > locking
> J> > to separate RX and TX part, these unlock/lock was removed. However,
> later
> J> > this unlock/lock was added back:
> J> >
> J> >
> J> >
> http://svnweb.freebsd.org/base/head/sys/dev/e1000/if_igb.c?revision=209068&view=markup
> J> >
> J> > , without any comments for the reason it is added back.
> J> >
> J> > I did not want to add it back, there were problems that constrained
> me to
> J> do so, although its
> J> been some time, I'd be happy to do some testing again without and see.
>
> Can you please dig through mail archives to identify these problems? I
> can't imagine any.
>
>
It may not be in email, there were tests going on internally here that I
often was working
with...  At this point it doesn't matter, Alexander says its running
without, I will have some
more testing on current code and go from there.

Jack