Re: [PATCH] [PATCH] Gaurantee spinlocks implicit barrier for!PREEMPT_COUNT

[Christian Ruppert]

Hi Vineet,

Our stress testing campaign has just successfully completed on this
patch. It seems to solve several issues we have seen in unpatched
versions, amongst others the original timer issue, a crash in hrtimer
rb-tree manipulation etc.

Greetings,
  Christian

On Wed, Apr 03, 2013 at 07:41:22PM +0530, Vineet Gupta wrote:
> spinlocks built in a !PREEMPT_COUNT config don't have the compiler
> barrier provided by preempt_* routines. This can break lot of code which
> relies on barrier semantics.
> 
> This manifested as random crashes in timer code when stress testing
> ARC Linux (3.9-rc3): !SMP && !PREEMPT_COUNT
> 
> [...]
> 
> Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> Reported-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx>
Tested-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Christian Ruppert <christian.ruppert@xxxxxxxxxx>
> Cc: Pierrick Hascoet <pierrick.hascoet@xxxxxxxxxx>
> Cc: Robert Love <rml@xxxxxxxxx>
> Cc: kpreempt-tech@xxxxxxxxxxxxxxxxxxxxx
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Steven Rostedt <srostedt@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> [...]
-- 
  Christian Ruppert              ,          <christian.ruppert@xxxxxxxxxx>
                                /|
  Tel: +41/(0)22 816 19-42     //|                 3, Chemin du Pré-Fleuri
                             _// | bilis Systems   CH-1228 Plan-les-Ouates
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