> On Thu, Mar 23, 2017 at 11:25:49AM -0700, [email protected] wrote: > > From: Kan Liang <[email protected]> > > > > When setting FREEZE_WHILE_SMM bit in IA32_DEBUGCTL, all > performance > > counters will be effected. There is no way to do per-counter freeze on > > smi. So it should not use the per-event interface (e.g. ioctl or event > > attribute) to set FREEZE_WHILE_SMM bit. > > > > Adds sysfs entry /sys/device/cpu/freeze_on_smi to set > FREEZE_WHILE_SMM > > bit in IA32_DEBUGCTL. When set, freezes perfmon and trace messages > > while in SMM. > > Value has to be 0 or 1. It will be applied to all possible cpus. > > So is there ever a good reason to not set this?
For me, I don't see any drawbacks to set it unconditionally. But I'm not sure if there is someone else who may want the counter running in SMI. If there is no objection, I will set the FREEZE_WHILE_SMM bit unconditionally in next version. Thanks, Kan
