Hi Bart! > Zoned UFS vendors need the data temperature information. Hence this > patch series that restores write hint information in F2FS and in the > block layer. The SCSI disk (sd) driver is modified such that it passes > write hint information to SCSI devices via the GROUP NUMBER field. I don't have any particular problems with your implementation, although I'm still trying to wrap my head around how to make this coexist with my I/O hinting series. But I guess there's probably not going to be a big overlap between devices that support both features. However, it still pains me greatly to see the SBC proposal being intertwined with the travesty that is streams. Why not define everything in the IO advice hints group descriptor? I/O hints already use GROUP NUMBER as an index. Why not just define a few permanent hint descriptors? What's the point of the additional level of indirection to tie this new feature into streams? RSCS basically says "ignore the streams-specific bits and bobs and do this other stuff instead". What does the streams infrastructure provide that can't be solved trivially in the IO advise mode page alone? For existing UFS devices which predate RSCS and streams but which support getting data temperature from GROUP NUMBER, what is the mechanism for detecting and enabling the feature? -- Martin K. Petersen Oracle Linux Engineering
