The timing is per-operation, not per total run. Even if we get one timer interrupt in there, it's going to be one bad data point. I'm fine with that.
But, me, i'm only taking 128 samples. I think that's more the enough and it runs in maybe several dozen microseconds. ron On Mon, Mar 28, 2016 at 3:29 PM ron minnich <[email protected]> wrote: > I'm still testing on linux. Akaros comes later :-) > > On Mon, Mar 28, 2016 at 2:59 PM Barret Rhoden <[email protected]> > wrote: > >> On 2016-03-28 at 21:46 ron minnich <[email protected]> wrote: >> > https://github.com/akaros/fputest >> > >> > >> > We're getting there. It's now using gcc intrinsics, which hopefully >> > are more correct. Still trying to get sane timing for the "no op" >> > case. >> >> i'd be concerned if the intrinsics are right and our own versions are >> wrong. hopefully that won't be the case after this gets sorted out. >> >> >> given that n = 1000000 and rdtsc alone takes O(30) ticks, you're >> probably getting interference from the timer IRQ, even on Akaros Core 0. >> here's two quick things to try: >> >> call uthread_mcp_init() somewhere in main. that'll make you an MCP. >> it's a bit hacky. verify that it's working with a ps or pip. >> >> check your tsc overhead against __procinfo.timing_overhead or against >> the console output during boot, e.g. >> >> TSC overhead (Min: 32, Max: 36) >> >> i didn't look at any of the actual FPU stuff for issues yet. >> >> barret >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Akaros" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "Akaros" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. For more options, visit https://groups.google.com/d/optout.
