Messages in this thread | | | Date | Mon, 18 Jun 2012 10:00:56 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH V2] tmp patch to fix hotplug issue in CMCI storm |
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On Mon, 18 Jun 2012, Chen Gong wrote: > index 92d8b5c..0493525 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c > +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c > @@ -40,6 +40,7 @@ static DEFINE_RAW_SPINLOCK(cmci_discover_lock); > static DEFINE_PER_CPU(unsigned long, cmci_time_stamp); > static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt); > static DEFINE_PER_CPU(unsigned int, cmci_storm_state); > +static DEFINE_PER_CPU(unsigned long, cmci_storm_hcpu_status);
Why do you insist on having another status variable, which does actually nothing than obfuscate the code?
Look at the usage sites:
> __this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED); > + __this_cpu_write(cmci_storm_hcpu_status, CMCI_STORM_HCPU_NONE);
> __this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE); > + __this_cpu_write(cmci_storm_hcpu_status, CMCI_STORM_HCPU_ACTIVE);
So it's a shadow variable of cmci_storm_state for no value.
And all you do with it is:
> +void mce_intel_hcpu_update(unsigned long cpu) > +{ > + unsigned long *status = &per_cpu(cmci_storm_hcpu_status, cpu); > + > + if (*status == CMCI_STORM_HCPU_ACTIVE) {
This can be checked with the existing variable as well. And your check leaves CMCI_STORM_SUBSIDED as a stale value around.
This simply wants to check
if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE) atomic_dec(&cmci_storm_on_cpus);
and unconditionally clear the state
per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
Right?
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