lkml.org 
[lkml]   [2011]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2 v2] WARN_ON_SMP(): Allow use in if statements on UP
From
Date
On Fri, 2011-03-18 at 10:12 +0100, Peter Zijlstra wrote:
> On Thu, 2011-03-17 at 17:56 -0400, Steven Rostedt wrote:
> > + * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
> > + * returns 0 for uniprocessor settings.
>
> Arguably most spin_is_locked() usages should be removed in favour of
> something like lockdep_assert_held().
>
> The latter only emits code then built with lockdep enabled and it checks
> we are indeed the owner, not some random other cpu.
>

Perhaps we should have lockdep_assert_held() also be in
"spin_is_locked()". The warning with spin_is_locked() is still nice to
have because it can trigger on production systems that might find a code
path that it's not locked. lockdep is too heavy to run on production
systems. But if lockdep is enabled, the spin_is_locked() should probably
check ownership too.

-- Steve




\
 
 \ /
  Last update: 2011-03-18 13:17    [W:0.140 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site