Re:The Case of the Extra 40ms
by amluto on Tuesday December 15, 2020 @02:10PM
(#25433784)
Hah, you must never have tried this on an otherwise idle stock Sandy Bridge before Linux added mitigations :)
x86 interrupts are slow but at least reasonably consistent on a non-idle system. If your system is deeply enough into its various idle states, this is not at all true any more. I’ve seen latencies over 10ms on Sandy Bridge with C1E enabled.
Re:The Case of the Extra 40ms
by FpUser on Tuesday December 15, 2020 @04:58PM
(#25435754)
Linux was on Pi 4. On PC it was actually Windows. The first version went out some 7 years ago I think and was rock solid since the beginning. They must've done something right ;)
x86 interrupts are slow but at least reasonably consistent on a non-idle system. If your system is deeply enough into its various idle states, this is not at all true any more. I’ve seen latencies over 10ms on Sandy Bridge with C1E enabled.