Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-08 Thread Drew Richardson
On Fri, May 08, 2015 at 03:09:03PM +0100, Steven Rostedt wrote: > On Tue, 5 May 2015 07:54:46 -0700 > Drew Richardson wrote: > > > CLOCK_MONOTONIC_RAW will advance more constantly than CLOCK_MONOTONIC. > > > > Imagine someone is trying to optimize a particular program to reduce > > instructions

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-08 Thread Steven Rostedt
On Tue, 5 May 2015 07:54:46 -0700 Drew Richardson wrote: > CLOCK_MONOTONIC_RAW will advance more constantly than CLOCK_MONOTONIC. > > Imagine someone is trying to optimize a particular program to reduce > instructions executed for a given workload while minimizing the effect > on runtime. Also

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-07 Thread Mathieu Desnoyers
- Original Message - > On Tue, 5 May 2015 07:54:46 -0700 > Drew Richardson wrote: > > > CLOCK_MONOTONIC_RAW will advance more constantly than CLOCK_MONOTONIC. > > > > Imagine someone is trying to optimize a particular program to reduce > > instructions executed for a given workload while

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-07 Thread Steven Rostedt
On Tue, 5 May 2015 07:54:46 -0700 Drew Richardson wrote: > CLOCK_MONOTONIC_RAW will advance more constantly than CLOCK_MONOTONIC. > > Imagine someone is trying to optimize a particular program to reduce > instructions executed for a given workload while minimizing the effect > on runtime. Also s

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-05 Thread Drew Richardson
On Mon, May 04, 2015 at 09:57:48PM +0100, Peter Zijlstra wrote: > On Mon, May 04, 2015 at 01:05:19PM -0700, Drew Richardson wrote: > > I'm collecting and merging data from perf, with Android Atrace data > > (writes to /sys/kernel/debug/tracing/trace_marker) which ends up in > > the ftrace stream an

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-04 Thread Peter Zijlstra
On Mon, May 04, 2015 at 01:05:19PM -0700, Drew Richardson wrote: > I'm collecting and merging data from perf, with Android Atrace data > (writes to /sys/kernel/debug/tracing/trace_marker) which ends up in > the ftrace stream and other measurements collected from > userspace. Currently the only cloc

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-04 Thread John Stultz
On Mon, May 4, 2015 at 1:05 PM, Drew Richardson wrote: > On Mon, May 04, 2015 at 04:10:05PM +0100, Mathieu Desnoyers wrote: >> - Original Message - >> > Expose the NMI safe accessor to the monotonic raw clock to the >> > tracer. The mono clock was added with commit >> > 1b3e5c0936046e7e023

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-04 Thread Drew Richardson
On Mon, May 04, 2015 at 04:10:05PM +0100, Mathieu Desnoyers wrote: > - Original Message - > > Expose the NMI safe accessor to the monotonic raw clock to the > > tracer. The mono clock was added with commit > > 1b3e5c0936046e7e023149ddc8946d21c2ea20eb. Although the monotonic raw > > clock ca

Re: [PATCH] ftrace: Provide trace clock monotonic raw

2015-05-04 Thread Mathieu Desnoyers
- Original Message - > Expose the NMI safe accessor to the monotonic raw clock to the > tracer. The mono clock was added with commit > 1b3e5c0936046e7e023149ddc8946d21c2ea20eb. Although the monotonic raw > clock cannot be used to compare time between different machines, it is > not perterbe