On Mon, Sep 25, 2023 at 12:54:48PM -0500, Mike Christie wrote: > I think we want to figure out Hannes's patches first. Yes. > For a new EH design we will want to be able to do multiple TMFs in parallel > on the same host/target right? > > The problem is that we need to be able to make forward progress in the EH > path and not fail just because we can't allocate memory for a TMF related > struct. To accomplish this now, drivers will use mempools, preallocate TMF > related structs/mem/tags with their scsi_cmnd related structs, preallocate > per host/target/device related structs or ignore what I wrote above and just > fail. > > Hannes's patches fix up the eh callouts so they don't pass in a scsi_cmnd > when it's not needed. That seems nice because after that, then for your new > EH we can begin to standardize on how to handle preallocation of drivers > resources needed to perform TMFs for your new EH. It could be a per > device/target/host callout to allow drivers to preallocate, then scsi-ml calls > into the drivers with that data. It doesn't have to be exactly like that or > anything close. It would be nice for drivers to not have to think about this > type of thing and scsi-ml just to handle the resource management for us when > there are multiple TMFs in progress. Exactly!
