On 02/26/2014 03:04 PM, Stephane Eranian wrote: > On Wed, Feb 26, 2014 at 3:39 AM, Andy Lutomirski <l...@amacapital.net> wrote: >> On 02/17/2014 10:07 PM, Yan, Zheng wrote: >>> >>> This patch series adds LBR call stack support. User can enabled/disable >>> this through an sysfs attribute file in the CPU PMU directory: >>> echo 1 > /sys/bus/event_source/devices/cpu/lbr_callstack >> >> This seems like an unpleasant way to control this. It would be handy to >> be able to control this as an option to perf record. >> > That would mean you'd be root for perf. > Or are you suggesting a perf event option? But then, you'd expose > arch-specific > feature at the API level. >
Another option is enable this feature by default if hardware supports it. But it causes LBR contention between events that want callstack and evnets that want LBR. Regards Yan, Zheng -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
