lkml.org 
[lkml]   [2003]   [Feb]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: more signal locking bugs?
Linus Torvalds wrote:

>In short, everything really seems to be pointing that way: the current
>task lock simply _is_ broken, and has apparently always been broken (but
>the ABBA deadlock is just extremely rare in practice, since you have to
>get an interrupt at just the right point on one CPU, while you have the AB
>case on another).\
>
ABBA is not a deadlock, because linux read_locks permit recursive calls.

read_lock(tasklist_lock);
task_lock(tsk);
read_lock(tasklist_lock);

Does not deadlock, nor any other ordering.

The tasklist_lock is never taken for write from bh or irq context.

--
Manfred

-
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 13:33    [W:0.041 / U:0.440 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site