Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 12 Dec 2012 19:09:33 -0800 | Subject | Re: [GIT PULL] perf changes for v3.8 |
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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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