On Thu, Feb 09, 2023 at 04:09:05PM +0900, Shin'ichiro Kawasaki wrote: > The valid data bytes accounting is used for zone_reset_threshold option. > This accounting usage has two issues. The first issue is unexpected > zone reset due to different IO ranges. The valid data bytes accounting > is done for all IO ranges per device, and shared by all jobs. On the > other hand, the zone_reset_threshold option is defined as the ratio to > each job's IO range. When a job refers to the accounting value, it > includes writes to IO ranges out of the job's IO range. Then zone reset > is triggered earlier than expected. > > The second issue is accounting value initialization. The initialization > of the accounting field is repeated for each job, then the value > initialized by the first job is overwritten by other jobs. This works as > expected for single job or multiple jobs with same write range. However, > when multiple jobs have different write ranges, the overwritten value is > wrong except for the last job. > > To ensure that the accounting works as expected for the option, check > that write ranges of all jobs are same. If jobs have different write > ranges, report it as an error. Initialize the accounting field only once > for the first job. All jobs have same write range, then one time > initialization is enough. Update man page to clarify this limitation of > the option. > > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> > --- Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
