Re: Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6

From: Andrea Vai
Date: Mon Nov 25 2019 - 09:58:44 EST


Il giorno lun, 25/11/2019 alle 18.29 +0800, Ming Lei ha scritto:
> On Mon, Nov 25, 2019 at 11:11:00AM +0100, Andrea Vai wrote:
> > Il giorno lun, 25/11/2019 alle 11.54 +0800, Ming Lei ha scritto:
> > > On Sat, Nov 23, 2019 at 04:44:55PM +0100, Andrea Vai wrote:
> > > > Il giorno sab, 23/11/2019 alle 15.28 +0800, Ming Lei ha
> scritto:
> > > > >
> > > > > Please post the log of 'lsusb -v', and I will try to make a
> > > patch
> > > > > for
> > > > > addressing the issue.
> > > >
> > > > attached,
> > >
> > > Please apply the attached patch, and re-build & install & reboot
> > > kernel.
> > >
> > > This time, please don't switch io scheduler.
> >
> > # patch -p1 < usb.patch outputs:
> >
> > (Stripping trailing CRs from patch; use --binary to disable.)
> > patching file block/blk-mq.c
> > Hunk #1 succeeded at 1465 (offset 29 lines).
> > Hunk #2 succeeded at 3061 (offset 13 lines).
> > (Stripping trailing CRs from patch; use --binary to disable.)
> > patching file drivers/scsi/scsi_lib.c
> > Hunk #1 succeeded at 1902 (offset -37 lines).
> > (Stripping trailing CRs from patch; use --binary to disable.)
> > patching file drivers/usb/storage/scsiglue.c
> > Hunk #1 succeeded at 651 (offset -10 lines).
> > (Stripping trailing CRs from patch; use --binary to disable.)
> > patching file include/linux/blk-mq.h
> > Hunk #1 succeeded at 226 (offset -162 lines).
> > (Stripping trailing CRs from patch; use --binary to disable.)
> > patching file include/scsi/scsi_host.h
> > patch unexpectedly ends in middle of line
> > patch unexpectedly ends in middle of line
> >
> > Just to be sure I have to go on, is this correct? Sounds like an
> error
> > but I don't know if it is important.
>
> Looks there is small conflict, however it has been fixed by patch,
> so
> it is correct, please go on your test.

Done, it still fails (2000 seconds or more to copy 1GB) :-(

cat /sys/block/sdf/queue/scheduler outputs:
[mq-deadline] none

What to try next?

Thanks,
Andrea