Messages in this thread | | | Subject | Re: [PATCH V7] irq: Track the interrupt timings | From | Daniel Lezcano <> | Date | Thu, 23 Jun 2016 15:12:25 +0200 |
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On 06/23/2016 12:12 PM, Thomas Gleixner wrote: > On Thu, 23 Jun 2016, Daniel Lezcano wrote: >> On 06/23/2016 10:41 AM, Thomas Gleixner wrote: >>> Is it really required to do this per interrupt rather than providing per cpu >>> statistics of interrupts which arrived in the last X seconds or whatever >>> timeframe is relevant for this. >> >> Perhaps I am misunderstanding but if the statistics are done per cpu without >> tracking per irq timings, it is not possible to extract a repeating pattern >> for each irq and have an accurate prediction. > > I don't see why you need a repeating pattern for each irq. All you want to > know is whether there are repeating patterns of interrupts on a particular > cpu. > > struct per_cpu_stat { > u32 irq; > u64 ts; > }; > > storing 32 entries of the above should give you enough information about > patterns etc. If you have a high rate of interrupts on that cpu it does not > matter at all whether thats from one or several devices. If you have only a > few then this storage is sufficient to get the desired information.
Mmmh, yes. I will investigate this patchset by replacing the percpu irqdesc's timings field by a per cpu irq event timings array.
Thanks !
-- Daniel
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