Messages in this thread | | | Subject | Re: [PATCH v3 0/6] clocksource: rework Atmel TCB timer driver | From | Daniel Lezcano <> | Date | Wed, 28 Mar 2018 15:03:11 +0200 |
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On 28/03/2018 12:29, Alexander Dahl wrote: > Hello Daniel, > > Am Dienstag, 27. März 2018, 13:30:22 CEST schrieb Daniel Lezcano: >> Can you can give a rough amount for the irq rate on the timer ? > > I used itop [1] now to get a rough estimate. First with kernel v4.14.29-rt25 > (fully preempt RT): > > INT NAME RATE MAX > 19 [ vel tc_clkevt] 397 Ints/s (max: 432) > 26 [ vel eth0] 4 Ints/s (max: 38) > > Next test with kernel v4.15.13 gives (slightly slower, but non-RT): > > INT NAME RATE MAX > 19 [ vel tc_clkevt] 248 Ints/s (max: 273) > 26 [ vel eth0] 4 Ints/s (max: 11) > > With kernel v4.16-rc7 plus this patch series and tcb as clocksource: > > INT NAME RATE MAX > 17 [vel timer@fffa] 2164 Ints/s (max: 2183) > 26 [ vel eth0] 5 Ints/s (max: 10) > > Is this the information you wanted? If not, could you point me on how to get > the requested irq rate?
It is perfect. Thanks!
It confirms what I was worried about: the clocksource wraps up too quickly thus raising an interrupt every 400us. That is why I asked Alexande about a prescalar register.
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