Re: [PATCH 11/14] x86: Populate cpu_enabled_map

From: Alex Chiang
Date: Fri Jul 18 2008 - 19:06:55 EST

* H. Peter Anvin <hpa@xxxxxxxxx>:
> Alex Chiang wrote:
>> Populate the cpu_enabled_map correctly.
>> Note that this patch does not actually make any decisions based
>> on the contents of the map.
>> However, as the map is presented via sysfs in:
>> /sys/devices/system/cpu/
>> It should be populated correctly.
>> There will be a user-visible change under the above directory.
>> cpuN/ entries for firmware-disabled CPUs will now appear, whereas
>> before, they did not due to a check against ACPI_MADT_ENABLED.
>> The cpuN/ entries will be empty, and the online file in the
>> above directory will reflect which CPUs are actually schedulable.
>> Signed-off-by: Alex Chiang <achiang@xxxxxx>
>> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
>> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Cc: H. Peter Anvin <hpa@xxxxxxxxx>
> From an x86 standpoint this patchset seems reasonable to me.
> Acked-by: H. Peter Anvin <hpa@xxxxxxxxx>

Thanks Peter. Let me try and rework the patchset according to
Russell's suggestion here:

That approach seems cleaner to me.

> Obviously, if the sematics of the operations don't make sense
> for other architectures -- which I will leave up to the
> affected maintainers -- then that should be carefully
> considered if the generic operations can be done better.

Russell's solution avoids the issue with the ability to #define
the check away for archs that don't care.



To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at