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SubjectRe: [GIT PULL] perf changes for v3.8
On Wed, Dec 12, 2012 at 7:02 PM, David Ahern <dsahern@gmail.com> wrote:
>
> Can you add -v and see if it spits out more info?

No more info.

Sure, it does the usual "do you have an APIC" message (it does that
without "-v" too), which isn't useful:

Error: sys_perf_event_open() syscall returned with 95 (Operation not
supported) for event cycles:pp. /bin/dmesg may provide additional
information.

No hardware sampling interrupt available. No APIC? If so then you
can boot the kernel with the "lapic" boot parameter to force-enable
it.

And yes, I have a local apic. Every single modern CPU does.

The error message is garbage and actively misleading. Lack of an APIC
is just about the *least* likely possible reason for the EOPNOTSUPP
error return.

Linus


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