Re: [OMPI devel] Use non-cpu frequency for timers

2016-05-20 Thread Paul Hargrove
Abhishek, That frequency variable doesn't need to be the CPU frequency. If you look at opal/mca/timer/linux/timer_linux_component.c:opal_timer_linux_find_freq() you will see the initialization for opal_timer_linux_freq. In the case of PPC the time stamp counter runs at a frequency, distinct from

[OMPI devel] Use non-cpu frequency for timers

2016-05-20 Thread Abhishek Joshi
Hi, In amd64, we have rdtsc instruction which uses a timer updated at cpu frequency. The frequency is given by variable, opal_timer_linux_freq which is the cpu frequency. Consider the case where a timer updated at non-cpu frequency is to be used. Question: In this case, how do we specify the fr