Corey Hickey wrote:

Patrick McHardy wrote:

quoted

quoted

+    if ((err = sfq_q_init(&tmp, opt)))
+        return err;

This will also use defaults for all unspecified values. It would
be more consistent with other qdiscs to only change those values
that are actually specified, so something like "tc qdisc change ...
perturb 10" will *only* change the perturbation parameter.

I'm fixed this for all the parameters except one--your example above.
Since 0 is a valid value for perturb, I can't see any clever way to
differentiate between the user specifying "perturb 0" or leaving perturb
unspecified. Either way, opt->perturb_period is 0.

The only way I can see would be to add another member, say,
opt->perturb_specified, and use that accordingly. Unfortunately, this
would break usage of sfq with older versions of tc, so I'm hoping
there's a better approach.

Do you have any suggestions? I've looked at the other qdisc files and I
don't see any other instances like this.

Maybe use the nested compat attribute and split the base SFQ
struct in the individual members ..