Re: [patch] x86_64: fix sched_clock()

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

 



On Fri, May 25, 2007 at 11:03:15AM +0200, Andi Kleen wrote:
> > This?    I sent it to you earlier this week:
> 
> Sorry haven't processed those yet.
> 
> Ah. The correct fix here is to clear the tsc flag in boot_cpu_data
> when the option is set. Will do that.

Hmm I double checked this now; tsc_disable indeed clears
X86_FEATURE_TSC in identify_cpu and that should be always
called before anything sched_clock related runs on a CPU.

Also the only possibly faulting division is protected
by a cpu_has_tsc which even checks boot_cpu_data. this means
even if the resync frequency code was called for
some reason before the identify_cpu of a AP it should
still work. For the BP this definitely cannot happen.

I also tried it with qemu myself (both one and two cpus) and it worked

Rusty, was this really on a standard kernel? Was it with multiple
CPUs? 

-Andi
-
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]
  Powered by Linux