Re: [PATCH] cpuset and sched domains: sched_load_balance flag

Paul Jackson
2007-10-02T20:58:14Z

Thanks for the review, Randy. Good comments.

> > Acked-by: Paul Jackson <pj@sgi.com>
>
> Are there some attributions missing, else S-O-B ?

Yup - I should have written this line as:

Signed-off-by: Paul Jackson <pj@sgi.com>

> > +static int cpusets_overlap(struct cpuset *a, struct cpuset *b)
>
> inline ?

It makes no difference to the code generated. I tend to leave
out 'compiler optimization' hint words if I don't need them to
get the compiler to optimize. In this case, of a single use
file static routine, the compiler inlines anyway.

> > + q = NULL; csa = NULL; doms = NULL;
>
> That's not kernel style. Use either (Andrew would say the second one):
>
> q = csa = doms = NULL;
>
> or
> q = NULL;
> csa = NULL;
> doms = NULL;

You're right - and Andrew would be right as well, since the form:

q = csa = doms = NULL;

generates a compiler warning, as not all three pointers are the
same type.

So three lines of code it must be.

> > + if (q && !IS_ERR(q))
> > + kfree(q);
> > + if (csa)
>
> Don't need the conditional: kfree(NULL) is OK.

Yup - you're right - about the 'csa' check.

However the if(q ...) check is needed, because I have another bug
here. I allocated 'q' using kfifo_alloc(), so must free using
kfifo_free (or else leak the kfifo buffer memory.) Calls to
kfifo_free() have to guard against NULL pointers before the call.

Thanks, Randy!

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.925.600.0401