lkml.org 
[lkml]   [2004]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [Experimental CPU Hotplug PATCH] - Move migrate_all_tasks to CPU_DEAD handling
From
Date
On Thu, 2004-04-08 at 00:17, Srivatsa Vaddagiri wrote:
> On Wed, Apr 07, 2004 at 03:32:12PM +1000, Rusty Russell wrote:
> > But other tasks can do a getaffinity() on it and see the wrong affinity.
> > Probably not a big issue.
>
> hmm .. the fact that getaffinity reads the cpus_allowed mask w/o doing
> lock_cpu_hotplug makes it already racy wrt setaffinity?

But that's OK: that's a user race. It's like reading a file at the same
time as writing it.

> Maybe it needs to take CPU hotplug sem before it reads the mask?

Yes, taking it in both syscalls would work, too.

> I would like to run my stress tests for longer time before I send it
> for inclusion (i would be on vacation till next tuesday ..so maybe i will send
> in the patch after that!)

Thanks. BTW, can you take a look at the FIXME: in xics.c and change it
to be dynamic. Joel is having trouble proving it's a problem, and yet
Anton assures me that ioremap is needed, so CPUs not present at boot
which are brought in should be failing...

Thanks!
Rusty.
--
Anyone who quotes me in their signature is an idiot -- Rusty Russell

-
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 14:02    [W:0.061 / U:3.476 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site