Messages in this thread | | | Date | Tue, 27 Sep 2011 15:39:20 +0100 | From | "Jan Beulich" <> | Subject | Re: [PATCH] i386/bigsmp: eliminate false warnings regarding logical APIC ID mismatches |
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>>> On 27.09.11 at 15:35, Ingo Molnar <mingo@elte.hu> wrote:
> * Jan Beulich <JBeulich@novell.com> wrote: > >> These warnings (generally one per CPU) are a result of initializing >> x86_cpu_to_logical_apicid while apic_default is still in use, but the >> check in setup_local_APIC() being done when apic_bigsmp was already >> used as an override in default_setup_apic_routing(): >> >> Overriding APIC driver with bigsmp >> Enabling APIC mode: Physflat. Using 5 I/O APICs >> ------------[ cut here ]------------ >> WARNING: at .../arch/x86/kernel/apic/apic.c:1239 > setup_local_APIC+0x137/0x46b() >> Hardware name: ... >> CPU0 logical APIC ID: 1 != 0 >> Pid: 1, comm: swapper Not tainted 3.0.1-2011-08-09-jb #2 >> Call Trace: >> [<c1005f91>] try_stack_unwind+0x1b1/0x1f0 >> [<c1004cc7>] dump_trace+0x47/0x110 >> [<c1005b0b>] show_trace_log_lvl+0x4b/0x60 >> [<c1005b38>] show_trace+0x18/0x20 >> [<c1261435>] dump_stack+0x6d/0x72 >> [<c10355f7>] warn_slowpath_common+0x77/0xb0 >> [<c10356c3>] warn_slowpath_fmt+0x33/0x40 >> [<c13fda81>] setup_local_APIC+0x137/0x46b >> [<c13d1733>] native_smp_prepare_cpus+0x108/0x1cd >> [<c13c61ff>] kernel_init+0x37/0x12c >> [<c1264826>] kernel_thread_helper+0x6/0xd >> ---[ end trace 4eaa2a86a8e2da22 ]--- >> ... >> CPU 1 irqstacks, hard=f1c9a000 soft=f1c9c000 >> Booting Node 0, Processors #1 >> smpboot cpu 1: start_ip = 9e000 >> Initializing CPU#1 >> ------------[ cut here ]------------ >> WARNING: at .../arch/x86/kernel/apic/apic.c:1239 > setup_local_APIC+0x137/0x46b() >> Hardware name: ... >> CPU1 logical APIC ID: 2 != 8 >> ... >> >> Fix this (for the time being, i.e. until x86_32_early_logical_apicid() >> will get removed again, as Tehun says ought to be possible) by >> overriding the previously stored values at the point where the APIC >> driver gets overridden. >> >> Signed-off-by: Jan Beulich <jbeulich@novell.com> >> Cc: Tejun Heo <tj@kernel.org> >> Cc: stable@kernel.org (2.6.39 and onwards) >> >> --- >> arch/x86/kernel/apic/probe_32.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> --- 3.1-rc2/arch/x86/kernel/apic/probe_32.c >> +++ 3.1-rc2-i386-bigsmp-early-lapicid-override/arch/x86/kernel/apic/probe_32.c >> @@ -203,7 +203,18 @@ void __init default_setup_apic_routing(v >> if (!cmdline_apic && apic == &apic_default) { >> struct apic *bigsmp = generic_bigsmp_probe(); >> if (bigsmp) { >> + unsigned int cpu; >> + >> apic = bigsmp; >> + for_each_possible_cpu(cpu) { >> + if (early_per_cpu(x86_cpu_to_logical_apicid, >> + cpu) == BAD_APICID) >> + continue; >> + early_per_cpu(x86_cpu_to_logical_apicid, >> + cpu) = >> + bigsmp->x86_32_early_logical_apicid >> + (cpu); >> + } >> printk(KERN_INFO "Overriding APIC driver with %s\n", >> apic->name); >> } > > This could move into a separate function i suspect, which would > de-uglify it quite significantly?
If that's the only concern, then sure - I'll re-submit with this broken out.
Jan
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