b60cb9cc80
Print the "perfect" reference period for easier evaluation. Suggest a remedy to the missed ticks problem. Still, that wasn't satisfactory. Implemented a count of missed ticks to get to the bottom of this issue. Found that missed ticks always came to a perfect count of 40. Incidentally, the busy loop prints a line every 250 ms and the test spans 10 seconds. There are no such coincidences. Turns out that CONFIG_PRINTK_SYNC was set by default. This disables IRQs for the serial output duration, which can be quite long at 115200 bauds. Given a 60-ish character line length, this represents more than 5 ms of no IRQ servicing during a timer latency measurement test which is bad. So make sure CONFIG_PRINTK_SYNC=n for proper statistics. Signed-off-by: Nicolas Pitre <npitre@baylibre.com> |
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| .. | ||
| cycle64 | ||
| starve | ||
| timer_api | ||
| timer_behavior | ||
| timer_error_case | ||
| timer_monotonic | ||