Messages in this thread Patch in this message | | | Date | Thu, 18 Aug 2011 13:54:44 +0100 | From | "Jan Beulich" <> | Subject | [PATCH] i386/bigsmp: eliminate false warnings regarding logical APIC ID mismatches |
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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); }
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