On Thu, Feb 01, 2007 at 12:26:33PM +0100, Andi Kleen wrote:
>
> > +extern void time_initialize_cpu(void);
>
> Never put externs into .c files. Multiple occurrences.
Ok, will fix it, sorry.
> > +void time_initialize_cpu(void *info)
> > +{
> > + unsigned long flags;
> > + int cpu = smp_processor_id();
>
> Are you sure this can never preempt?
yes, preemption is explicitly disabled in start_secondary() that
calls this function.
> > + /* FIXME: what speed does the cpu really start at; I doubt cpu_khz is right at this point ??!!!
>
> It should be. It comes from measurements. Unless the CPU changes frequency
> behind the kernel's back, but there is nothing that can be done then.
Well, I'm not sure. I think the global variable cpu_khz is wrong
in the first place. This should be per-cpu, because each CPU can
have a different frequency, right?
And cpu_khz is adjusted in time_cpufreq_notifier() when whichever
CPU's frequency changes. To me it seems that it's a leftover from
the times when all CPUs in a system ran at the same speed. I
think it should be killed. I just did not want to make too many
unrelated changes in one patchset.
It doesn't matter that much in this case that it probably is
wrong (as the comment explains)...
--
Jiri Bohac <[email protected]>
SUSE Labs, SUSE CZ
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
