On 05/04/2015 03:25 PM, Brian Fulton wrote:
Hi Jens, I've been actively looking at this bug. It was introduced with change e5437a073e658e8154b9e87bab5c7b3b06ed4255 (https://github.com/axboe/fio/commit/e5437a073e658e8154b9e87bab5c7b3b06ed4255). In this change, the time granularity was changed from microseconds to milliseconds. This change assumes that all loops take at least 1ms to complete. This is not always true and tests where the loop gets processed, regularly, in sub-millisecond time result in many zeroes being summed which, ultimately, causes a completely inaccurate runtime. I have a fix for this, but I want to verify that it doesn't break anything as it is changing the way the runtime is being calculated. We are using fio version 2.2.6, though this issue should still be present in the latest version (2.2.7). Below is a patch fix based of the latest version of fio 2.2.7:
Thanks, that makes more sense. Akash, can you confirm that this fixes it for you?
-- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
