Re: TSO not working?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Fri, Oct 28, 2011 at 02:24:04PM -0400, Thor Lancelot Simon wrote:
> > I added a sc_ev_txlargetso, which gets incremented by:
> >     if (m0->m_pkthdr.len > 32768)
> >             WM_EVCNT_INCR(&sc->sc_ev_txlargetso);
> 
> It'd be interesting, perhaps, to see how often we were actually even > 1500.

I added this:
                if (m0->m_pkthdr.len >= 32768)
                        WM_EVCNT_INCR(&sc->sc_ev_txtsolarge);
                if (m0->m_pkthdr.len >= 16384)
                        WM_EVCNT_INCR(&sc->sc_ev_txtsomedium);
                if (m0->m_pkthdr.len >= 1500)
                        WM_EVCNT_INCR(&sc->sc_ev_txtsomtu);

and here's the results:
for ttcp against a NetBSD client:
wm0 txtso                                    188555      695 misc
wm0 txtsomtu                                 188555      695 misc
wm0 txtsomedium                                  92        0 misc
wm0 txtsolarge                                    4        0 misc

glusterfs against a NetBSD client:
wm0 txtso                                    114607      690 misc
wm0 txtsomtu                                 114607      690 misc
wm0 txtsomedium                                1496        9 misc
wm0 txtsolarge                                  709        4 misc

glusterfs against a linux client:
wm0 txtso                                     86567     1185 misc
wm0 txtsomtu                                  86567     1185 misc
wm0 txtsomedium                                6897       94 misc
wm0 txtsolarge                                 2391       32 misc

> 
> > ttcp -t -l65536 -b524288 -D xen1-priv < /glpool/truc
> > 
> > (64k writes but a 512k TCP buffer) I get no "largetso".
> 
> Does the window ever have 32K of space, I wonder?  Maybe the delay is
> not large enough to ever let it open that wide.

We should have this in the trace ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--