lkml.org 
[lkml]   [2008]   [Jul]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] wait_task_inactive: don't use the dummy version when !SMP && PREEMPT


On Wed, 30 Jul 2008, Oleg Nesterov wrote:
>
> The patch looks monstrous because it moves the (unchanged) definition
> of wait_task_inactive() outside of "#ifdef CONFIG_SMP", but it is quite
> trivial.

Hmm. Doesn't this just deadlock in UP (PREEMPT) if wait_task_interactive()
is ever called from a no-preempt context?

And if that's never the case, the comment should be updated to reflect
that (right now it says that it's only invalid to call it with interrupts
disabled to avoid cross-IPI deadlocks).

Oh, and shouldn't it do a "yield()" instead of a cpu_relax() on UP?

Inquiring minds want to know. That function was very much expressly
designed for SMP, not for preemption, and I want to understand why it's
ok (_if_ it's ok).

Linus


\
 
 \ /
  Last update: 2008-07-30 19:49    [W:0.467 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site