Messages in this thread | | | Date | Fri, 25 Apr 2008 13:41:06 +0200 | From | Gabriel C <> | Subject | Re: [REGRESSION] x86: support for new UV apic |
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Gabriel C wrote: > Andi Kleen wrote: >> Ingo Molnar <mingo@elte.hu> writes: >> >>> * Priit Laes <plaes@plaes.org> wrote: >>> >>>> Hey, >>>> >>>> I am getting two following warnings (probable one per each CPU core) >>>> using the latest Linus's git: >>>> >>>> WARNING: at arch/x86/kernel/genapic_64.c:86 read_apic_id+0x30/0x62() >>>> Modules linked in: >>>> Pid: 1, comm: swapper Not tainted 2.6.25-03563-gf7288b1 #20 >>> thanks - could you check the patch below, does it fix the warnings? >> I think it would have been better to change the WARN_ON to >> >> WARN_ON(preemptible() && num_online_cpus() > 1) > > Hmm , I think you are right , Ingo's patch fixes the warning on boot but now I get one when I reboot the box. > >> Preemption is actually ok here because this runs before the other >> CPUs are started >> >> Alternative patch appended. > > I will test your patch in some minutes.
Your patch works better , at least for my box , 4 reboots with your patch and boot/reboot warnings are all gone.
>> >> Don't warn in read_apic_id() when preemptible but only one CPU online. >> >> Signed-off-by: Andi Kleen <andi@firstfloor.org> >> >> Index: linux/arch/x86/kernel/genapic_64.c >> =================================================================== >> --- linux.orig/arch/x86/kernel/genapic_64.c >> +++ linux/arch/x86/kernel/genapic_64.c >> @@ -83,7 +83,7 @@ unsigned int read_apic_id(void) >> { >> unsigned int id; >> >> - WARN_ON(preemptible()); >> + WARN_ON(preemptible() && num_online_cpus() > 1); >> id = apic_read(APIC_ID); >> if (uv_system_type >= UV_X2APIC) >> id |= __get_cpu_var(x2apic_extra_bits); > >
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