On 9/25/19 9:30 PM, Alan Stern wrote: > On Fri, 20 Sep 2019, Andrea Vai wrote: > >> Il giorno gio, 19/09/2019 alle 14.14 +0000, Damien Le Moal ha scritto: >>> On 2019/09/19 16:01, Alan Stern wrote: >>> [...] >>>> No doubt Andrea will be happy to test your fix when it's ready. >> >> Yes, of course. >> >>> >>> Hannes posted an RFC series: >>> >>> https://www.spinics.net/lists/linux-scsi/msg133848.html >>> >>> Andrea can try it. >> >> Ok, but I would need some instructions please, because I am not able >> to understand how to "try it". Sorry for that. > > I have attached the two patches to this email. You should start with a > recent kernel source tree and apply the patches by doing: > > git apply patch1 patch2 > > or something similar. Then build a kernel from the new source code and > test it. > > Ultimately, if nobody can find a way to restore the sequential I/O > behavior we had prior to commit f664a3cc17b7, that commit may have to > be reverted. Don't use patch1, it's buggy. patch2 should be enough to test the theory. -- Jens Axboe