Re: [BUG?] Re: maximum value that sched_clock() can return

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Am Freitag, 28. April 2006 07:34 schrieb Hareesh Nagarajan:
> On 4/27/06, Mauricio Lin <mauriciolin2000@xxxxxxxxxxxx> wrote:
> > Since sched_clock() function is implemented differently for each arch,
> > how can I figure out the maximum value sched_clock can return?
>
> This doesn't concern your question, but I was looking at:
> sched_clock() defined in arch/i386/kernel/timers/timer_tsc.c:
>
> <definition_sans_comments>
> unsigned long long sched_clock(void)
> {
>         unsigned long long this_offset;
> #ifndef CONFIG_NUMA
>         if (!use_tsc)
> #endif
>                 return jiffies_64 * (1000000000 / HZ);
>         rdtscll(this_offset);
>         return cycles_2_ns(this_offset);
> }
> </definition_sans_comments>
>
> Why do we have the second return statement in the first place? It will
> never be executed.

In case CONFIG_NUMA is defined and use_tsc is false, the first return will not 
be executed.

- Askadar

--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive:       http://mail.nl.linux.org/kernelnewbies/
FAQ:           http://kernelnewbies.org/faq/


[Index of Archives]     [Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]
  Powered by Linux