On Wed, 27 Nov 2019, Schmid, Carsten wrote: > > > > The sheer volume of testing (probably some terabytes by now) would > > exercise the wear leveling algorithm in the FTL. > > > But with "old kernel" the copy operation still is "fast", as far as i > understood. If FTL (e.g. wear leveling) would slow down, we would see > that also in the old kernel, right? > > Andrea, can you confirm that the same device used with the old fast > kernel is still fast today? You seem to be saying we should optimize the kernel for a pathological use-case merely because it used to be fast before the blk-mq conversion. That makes no sense to me. I suppose you have information that I don't. I assume that your employer (and the other corporations involved in this) have plenty of regression test results from a variety of flash hardware to show that the regression is real and the device is not pathological. I'm not privy to any of that information so I will shut up and leave you guys to it. -- > > This in itself seems unlikely to improve performance significantly. > > But if the flash memory came from a bad batch, perhaps it would have > > that effect. > > > > To find out, someone may need to source another (genuine) Kingston > > DataTraveller device. > >
