Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V6 01/37] tracing/hwlat: Use ktime_get_mono_fast_ns() | Date | Tue, 19 May 2020 23:45:10 +0200 |
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Steven Rostedt <rostedt@goodmis.org> writes: > On Sat, 16 May 2020 01:45:48 +0200 > Thomas Gleixner <tglx@linutronix.de> wrote: >> + if (enter) >> + nmi_ts_start = ktime_get_mono_fast_ns(); >> + else >> + nmi_total_ts += ktime_get_mono_fast_ns() - nmi_ts_start; >> >> if (enter) >> nmi_count++; >> @@ -165,20 +155,22 @@ void trace_hwlat_callback(bool enter) >> * Used to repeatedly capture the CPU TSC (or similar), looking for potential >> * hardware-induced latency. Called with interrupts disabled and with >> * hwlat_data.lock held. >> + * >> + * Use ktime_get_mono_fast() here as well because it does not wait on the >> + * timekeeping seqcount like ktime_get_mono(). > > When doing a "git grep ktime_get_mono" I only find > ktime_get_mono_fast_ns() (and this comment), so I don't know what to compare > that to. Did you mean another function?
Yeah. I fatfingered the comment. The code uses ktime_get_mono_fast_ns().
> The rest looks fine (although, I see other things I need to clean up in > this code ;-)
Quite some ...
Thanks,
tglx
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