Re: Slow I/O on USB media

[Andrea Vai <andrea.vai@unipv.it>]

Il giorno gio, 30/05/2019 alle 06.25 -0700, Greg KH ha scritto:
> [...]
Hi,

> Any chance you can use 'git bisect' to find the offending commit?
Yes, I am doing it as I managed to build the kernel from source

> 
> And did you accidentally turn on "sync" for the filesystem? 
Sorry, I don't think so but actually I don't know exactly what it is
nor how to check it...

>  How do you
> know the old kernel really flushed the buffers out in 1 minute? 

I used to try to unmount the usb media (e.g. "eject" using Nautilus
file manager), and got a message stating the filesystem was in use and
could not be mounted, so always answered to not eject it until it was
unmounted without any warning... does it make sense?

>  But 12
> minutes is really long, did anything else change in your userspace
> between the kernel changes as well?
I am not sure if I understand correctly the "userspace" you mention:
if you mean my home directory and contents, settings etc, then yes,
maybe... but while I am doing the tests I am quite sure I didn't
change anything, and double-checked many times that the 4.20 kernel is
always working (I usually boot up with it when I need to do the usual
day work).

Thank you for any further explanation,

Bye
Andrea