Messages in this thread | | | Date | Mon, 18 Apr 2005 14:25:35 +0530 | From | Sripathi Kodi <> | Subject | x86_64: How to disable local APIC timer interrupts? |
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Hi,
I am trying to disable the local APIC timer interrupts on x86_64 machine, but finding that it just doesn't work. I am trying to find out if I am doing something wrong or if there is a problem with these CPUs.
I have a dual-cpu x86_64 machine and I have booted up with 2.6.11 kernel and nmi_watchdog=2. I called disable_APIC_timer() function, which seems to be setting the 16th bit of the APIC timer register, which is what the AMD document suggests to disable the timer. This function is in fact __init, but I changed it not to be so. I noticed that we continue to see local APIC timer interrupts on the very CPU where I called disable_APIC_timer. I have a printk in smp_apic_timer_interrupt() to verify this. Booting the machine with maxcpus=1 didn't have any effect on the outcome. CPUs are of the following type:
processor : 0 vendor_id : AuthenticAMD cpu family : 15 model : 5 model name : AMD Opteron(tm) Processor 248 stepping : 8 cpu MHz : 2193.510 cache size : 1024 KB fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext lm 3dnowext 3dnow bogomips : 4325.37 TLB size : 1088 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: ts ttp
Please let me know if I am doing something wrong and if I should do something else to disable local APIC timer interrupts. I need to disable these interrupts to solve a problem in LKCD dumping. smp_apic_timer_interrupt eventually calls update_process_times, which is causing problem in a particular LKCD dump case I am looking at.
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Thanks and regards, Sripathi. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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