Thanks so much for your comment, Martin ;) That's really helpful. Jianchao On 2021/7/8 11:23 AM, Martin K. Petersen wrote: > > Wang, > >> We have a sata ssd with following parameters, >> >> max_ws_blocks = 0 >> max_unmap_blocks = 262143 >> lbprz = 1 >> lbpu = 1 >> unmap_limit_for_ws = 0 > > The device is explicitly asking for us to use UNMAP so the older kernel > choosing WRITE SAME(16) was not correct. > > I have been working on an update to the discard/zeroing heuristics that > I'll post when 5.15 opens next week. But based on what's reported it by > your device we would still choose UNMAP for discards. LBPRZ only affects > which command we use for zeroing. >
