On Jul 18, 2023 / 13:56, Niklas Cassel wrote: > On Fri, Jul 07, 2023 at 12:14:56PM +0900, Shin'ichiro Kawasaki wrote: > > A recent commit modified the max_open_zones option to improve handling > > of zoned block devices with max_active_zones limit. Modify description > > of the option to meet the change. > > > > For that purpose, explain the relation between the max_open_zones option > > and the device side limits max_active_zones and max_open_zones. Also > > mention about three zone conditions 'implicit open', 'explict open' and > > 'closed'. And replace the word 'zone state' with 'zone condition'. > > > > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> > > --- > > HOWTO.rst | 44 ++++++++++++++++++++++++++++---------------- > > fio.1 | 36 ++++++++++++++++++++++++------------ > > 2 files changed, 52 insertions(+), 28 deletions(-) > > > > diff --git a/HOWTO.rst b/HOWTO.rst > > index 2e1e55c2..4d50ad41 100644 > > --- a/HOWTO.rst > > +++ b/HOWTO.rst > > @@ -1056,22 +1056,34 @@ Target file/device > > > > .. option:: max_open_zones=int > > > > - A zone of a zoned block device is in the open state when it is partially > > - written (i.e. not all sectors of the zone have been written). Zoned > > - block devices may have a limit on the total number of zones that can > > - be simultaneously in the open state, that is, the number of zones that > > - can be written to simultaneously. The :option:`max_open_zones` parameter > > - limits the number of zones to which write commands are issued by all fio > > - jobs, that is, limits the number of zones that will be in the open > > - state. This parameter is relevant only if the :option:`zonemode` =zbd is > > - used. The default value is always equal to maximum number of open zones > > - of the target zoned block device and a value higher than this limit > > - cannot be specified by users unless the option > > - :option:`ignore_zone_limits` is specified. When > > - :option:`ignore_zone_limits` is specified or the target device has no > > - limit on the number of zones that can be in an open state, > > - :option:`max_open_zones` can specify 0 to disable any limit on the > > - number of zones that can be simultaneously written to by all jobs. > > + When a zone of a zoned block device is partially written (i.e. not all > > + sectors of the zone have been written), the zone is in one of three > > + conditions: 'implicit open', 'explicit open' or 'closed'. Zoned block > > + devices may have a limit called 'max_open_zones' (same name as the > > + parameter) on the total number of zones that can simultaneously be in > > + the 'implicit open' or 'explicit open' conditions. Zoned block devices > > + may have another limit called 'max_active_zones', on the total number of > > + zones that can simultaneously be in the three conditions. The > > + :option:`max_open_zones` parameter limits the number of zones to which > > + write commands are issued by all fio jobs, that is, limits the number of > > + zones that will be in the conditions. When the device has the > > + max_open_zones limit and does not have the max_active_zones limit, the > > + :option:`max_open_zones` parameter limits the number of zones in the two > > + open conditions up to the limit. In this case, fio includes zones in the > > + two open conditions to the write target zones at fio start. When the > > + device has both the max_open_zones and the max_active_zones limits, the > > + :option:`max_open_zones` parameter limits the number of zones in the > > + three conditions up to the limit. In this case, fio includes zones in > > + the three conditions to the write target zones at fio start. > > + > > + This parameter is relevant only if the :option:`zonemode` =zbd is used. > > + The default value is always equal to the max_open_zones limit of the > > + target zoned block device and a value higher than this limit cannot be > > + specified by users unless the option :option:`ignore_zone_limits` is > > + specified. When :option:`ignore_zone_limits` is specified or the target > > + device does not have the max_open_zones limit, :option:`max_open_zones` > > + can specify 0 to disable any limit on the number of zones that can be > > + simultaneously written to by all jobs. > > While this is a wall of text, I don't really see a better way. > > This option really controls the maximum number of zones that fio will > issue writes to simultaneously. > > For clarity, I guess we could introduce a --max_write_zones option > and move this description there, and make --max_open_zones an alias > for --max_write_zones... But I'm not sure if it would be worth it. Actually, I also thought about the new option --max_write_zones. But I was not sure either if that is good for users, and just chose to keep the current option name. Let me keep it as it is, in v2.
