Re: [git-pull -tip] x86: Basic AMD Support for performance counters

[Ingo Molnar <mingo@elte.hu>]

* Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:

> On Sun, 2009-03-01 at 12:30 +0100, Ingo Molnar wrote:
> > * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> > 
> > > On Sun, 2009-03-01 at 09:36 +0100, Ingo Molnar wrote:
> > > > * Ingo Molnar <mingo@elte.hu> wrote:
> > > > 
> > > > > Seems to be working fine, here's the output from an Athlon 64 
> > > > > 3200+ (Sempron) box:
> > > > > 
> > > > >  Performance counter stats for 'ls':
> > > > > 
> > > > >       17.420811  task clock ticks     (msecs)
> > > > > 
> > > > >               0  CPU migrations       (events)
> > > > >              12  context switches     (events)
> > > > >             583  pagefaults           (events)
> > > > >        29760299  CPU cycles           (events)
> > > > >        29401642  instructions         (events)
> > > > >        12698498  cache references     (events)
> > > > >           66269  cache misses         (events)
> > > > > 
> > > > >  Wall-clock time elapsed:   687.999988 msecs
> > > > 
> > > > The patches cause a crash on another system - an Opteron system 
> > > > spontaneous reboots at this point during early bootup:
> > > > 
> > > > CPU 0/0x4 -> Node 0
> > > > tseg: 00cfe00000
> > > > CPU: Physical Processor ID: 0
> > > > CPU: Processor Core ID: 0
> > > > using C1E aware idle routine
> > > > AMD Performance Monitoring support detected.
> > > > ... num counters:    4
> > > > ... value mask:      0000000000000000
> > > > ... fixed counters:  0
> > > > ... counter mask:    000000000000000f
> > > > ACPI: Core revision 20081204
> > > > ftrace: converting mcount calls to 0f 1f 44 00 00
> > > > ftrace: allocating 16365 entries in 129 pages
> > > > Setting APIC routing to physical flat
> > > > masked ExtINT on CPU#0
> > > > ENABLING IO
> > > > [reboot]
> > > > 
> > > 
> > > Can you please share your config file.
> > 
> > any config file will crash that box. I used the 64-bit defconfig 
> > - i.e. 'make ARCH=x86_64 defconfig'.
> > 
> 
> Can you please try this patch:
> 
> diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
> index 266618a..5447cc0 100644
> --- a/arch/x86/kernel/cpu/perf_counter.c
> +++ b/arch/x86/kernel/cpu/perf_counter.c
> @@ -146,7 +146,9 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
>  	 * Generate PMC IRQs:
>  	 * (keep 'enabled' bit clear for now)
>  	 */
> -	hwc->config = ARCH_PERFMON_EVENTSEL_INT;
> +	/* Currently Interrupts are disabled on AMD */
> +	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
> +		hwc->config = ARCH_PERFMON_EVENTSEL_INT;

still crashes in a similar way.

hm, this box has nmi_watchdog=2, and the NMI watchdog uses the 
PMU too - will disable that.

	Ingo