Messages in this thread | | | Date | Fri, 9 Apr 2021 00:45:13 +0200 (CEST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH] riscv: keep interrupts disabled for BREAKPOINT exception |
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On Fri, 9 Apr 2021, Masami Hiramatsu wrote:
> > > Is this approach guaranteed to keep interrupt handling latency low enough > > > for the system not to be negatively affected, e.g. for the purpose of NTP > > > timekeeping? > > > > IMHO, interrupt latency can't be ensured if kprobes is triggered. > > Indeed. The latency depends on what the kprobe user handler does. Of course > it must be as minimal as possible... On x86, it is less than a few microseconds. > Thus it may be a jitter on hard realtime system, but not a big issue on > usual system like NTP timekeeping.
Ack. Assuming that the breakpoint exception will only disable interrupts if kprobes are in use it seems reasonable to me.
Thanks for double-checking.
Maciej
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