Hi Jens, Akash and I both discovered this bug and work together. He is currently on holiday for the next two weeks or so. I am currently using the same tests that originally discovered the bug to verify it is fixed. Out of curiosity, why is the comma required after the zero in order to initialize all elements to zero? I used this initializer instead of memset just as it was used here: https://github.com/axboe/fio/blob/master/cgroup.c#L26. Are there certain compilers that require the comma? I also checked the C99 spec http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf, Section 6.7.8, page 125, sections 1 and 21. I just want to make sure I'm not loosing my mind. Thanks, Brian On Mon, May 4, 2015 at 3:08 PM, Jens Axboe <axboe@xxxxxxxxx> wrote: > On 05/04/2015 04:02 PM, Jens Axboe wrote: >> >> 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? > > > Committed: > > http://git.kernel.dk/?p=fio.git;a=commit;h=95603b7470fac1917cb11bc686e60b4339f8a2fc > > Brian, I changed a few things: > > - DDIR_RWDIR_CNT exists for array sizing > - You need a ',' after that zero to clear the array > - Style > > -- > 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
