On Thu, Nov 04, 2021 at 04:26:37PM +0000, Phillip Chen wrote: > Hello all, > I've been hearing about the command duration limit feature (4.7 in the ACS-5 revision 8 and 5.2 in SPC-6 revision 1) as a more flexible and powerful alternative to priority commands. Does anyone have any plans to make this feature compatible with FIO? I imagine it would take quite a bit of work to even make CDL accessible to FIO, but I'm just curious is anyone making the effort? > Thanks, > Phillip Chen > > Seagate Internal Hello Phillip, Me and Damien Le Moal are currently working on adding support for command duration limits. They way that we have implemented it is to add a new IO priority class in the Linux IO priority API, by adding a new IO priority class (IOPRIO_CLASS_DL), for more info see here: https://www.spinics.net/lists/linux-block/msg71993.html Unfortunately the kernel patches are not shared yet, since the specs are in draft state. However, I'm working on improving the cmdprio support in FIO, so that it is easier to send in different IO prio classes + IO prio level combinations when using cmdprio_bssplit. The work in progress branch is here: https://github.com/floatious/fio/tree/cmdprio When that work is done, the only patch needed for FIO will be a one line patch to add IOPRIO_CLASS_DL to os/os-linux.h. Kind regards, Niklas
