lkml.org 
[lkml]   [2004]   [Oct]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8
From
Date
On Thu, 2004-10-21 at 11:53, Jens Axboe wrote:
> On Thu, Oct 21 2004, Thomas Gleixner wrote:
> > On Thu, 2004-10-21 at 11:12, Rui Nuno Capela wrote:
> > > [<e018e139>] queuecommand+0x70/0x7c [usb_storage] (24)
> >
> > As I already pointed out, this is a problem due to up(sema) in
> > queuecommand. That's one of the semaphore abuse points, which needs to
> > be fixed.
> >
> > The problem is that semaphores are hold by Process A and released by
> > Process B, which makes Ingo's checks trigger
>
> That's utter crap, it's perfectly valid use.

It's not!

>From the code:

init_MUTEX_LOCKED(&(us->sema));

This is used to wait for command completion and therefor we have the
completion API. It was used this way because the ancestor of completion
(sleep_on) was racy !

tglx




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.672 / U:1.332 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site