[LARTC] Patch accurate packet scheduling for ATM/ADSL

[Edouard Thuleau]

Hi,

2007/7/26, Russell Stuart <russell-tcatm at stuart.id.au>:
> On Wed, 2007-07-25 at 15:14 +0200, Edouard Thuleau wrote:
> > I use the patch
> > (http://ace-host.stuart.id.au/russell/files/tc/tc-atm/) for accurate
> > the packet scheduling on ATM/ADSL link and i think I've found a bug.
> > I tried to write to the author but he didn't answer me.
>
> Sorry.  :(  I have now.

Thanks for your answer.
>
> > I work on a Linux 2.6.17 with the iproute2-2.6.18-061002 package.
> > I change the type of the cell_align char to short of the struct
> > tc_ratespec in the file pkt_sched.h (in the include/linux/ directories
> > of iproute package and the kernel source) :
> >
> > struct tc_ratespec
> > {
> >       unsigned char   cell_log;
> >       unsigned char   __reserved;
> >       unsigned short  feature;        /* Always 0 in pre-atm patch kernels */
> > -     char            cell_align;     /* Always 0 in pre-atm patch kernels */
> > -     unsigned char   __unused;
> > +     short           cell_align;     /* Always 0 in pre-atm patch kernels */
> >       unsigned short  mpu;
> >       __u32           rate;
> > };
> >
> > The results are much better and with my tests, it works very nicely.
> >
> > If it can help someone,
>
> I can't see how that would change things as the cell align
> always lies within the range -7..0.  The only thing that
> springs to mind is perhaps you aren't using i386, and your
> CPU doesn't sign extend char's???  What CPU are you using?
>
Yes I use an ARM big-endian architecture, it's my problem.
I understood now.
If we put a short, the patch works for all architecture, no ?

Thanks.