Re: perf counters: problem with perf record

[Peter Zijlstra]

On Sun, 2009-11-15 at 03:14 +1000, Simon KÃmpflein wrote:
> Hello,
> 
> I have a problem with the new kernel perf tools in kernel 2.6.31.6 (very
> nice tools by the way). I like to monitor the cache-misses of a program.
> "perf stat -e cache-misses program" works without problems, but I can't
> get "perf record -e cache-misses program" working (even running as root
> and CONFIG_PERF_COUNTERS=y):
> 
> Error: perfcounter syscall returned with -1 (Operation not supported)
> Fatal: No CONFIG_PERF_COUNTERS=y kernel support configured?
> 
> strace of "perf stat":
> SYS_336(0x8508da0, 0x1074, 0xffffffff, 0xffffffff, 0) = 3
> 
> strace of "perf record":
> SYS_336(0x8508da0, 0xf85, 0xffffffff, 0xffffffff, 0) = -1 EOPNOTSUPP
> (Operation not supported)
> 
> My CPU is a "Intel(R) Pentium(R) M processor 1.80GHz":
> [    0.004337] p6 PMU driver.
> [    0.004343] ... version:                 0
> [    0.004345] ... bit width:               32
> [    0.004347] ... generic counters:        2
> [    0.004349] ... value mask:              00000000ffffffff
> [    0.004351] ... max period:              000000007fffffff
> [    0.004353] ... fixed-purpose counters:  0
> [    0.004355] ... counter mask:            0000000000000003

Does the bootlog perchance contain the output of?

        if (!cpu_has_apic) {
                pr_info("no APIC, boot with the \"lapic\" boot parameter
to force-enable it.\n");
                pr_info("no hardware sampling interrupt available.\n");
                x86_pmu.apic = 0;
        }

And does booting with the suggested lapic parameter cure your problems?

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