Re: [linux-usb-devel] System stalls using usb-storage

[Peter Osterlund <petero2@telia.com>]

Matthew Dharm <mdharm-kernel@one-eyed-alien.net> writes:

> On Sun, Jul 27, 2003 at 08:24:44AM +0200, Oliver Neukum wrote:
> > Am Donnerstag, 24. Juli 2003 05:00 schrieb Matthew Dharm:
> > > The question is, what is the best way to handle this.  I'm guessing that
> > > increasing the priority of the usb-storage control thread will help, but
> > > that's just a guess.  I'm not even sure how to go about doing that, tho...
> > 
> > A kernel thread in the block io path has to have a higher priority than
> > any user task. Otherwise a priority inversion is possible.
> 
> Reasonable.  So, other than renice at the command line, how does one go
> about setting this?

Try this patch. The loop device thread is doing the same thing.

diff -puN drivers/usb/storage/usb.c~usb-priority drivers/usb/storage/usb.c
--- linux/drivers/usb/storage/usb.c~usb-priority	Sun Jul 27 10:56:02 2003
+++ linux-petero/drivers/usb/storage/usb.c	Sun Jul 27 10:56:47 2003
@@ -302,6 +302,8 @@ static int usb_stor_control_thread(void 
 
 	current->flags |= PF_IOTHREAD;
 
+	set_user_nice(current, -20);
+
 	unlock_kernel();
 
 	/* signal that we've started the thread */

-- 
Peter Osterlund - petero2@telia.com
http://w1.894.telia.com/~u89404340