Re: [GIT PULL] RCU changes for v3.3

[Eric Dumazet]

Le mardi 24 janvier 2012 Ã 15:29 -0800, Paul E. McKenney a Ãcrit :

> And here is another version of the patch.
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> x86: Avoid invoking RCU when CPU is idle
> 
> The idle loop is a quiscent state for RCU, which means that RCU ignores
> CPUs that have told RCU that they are idle via rcu_idle_enter().  There
> are nevertheless quite a few places where idle CPUs use RCU, most commonly
> indirectly via tracing.  This patch fixes these problems for x86.
> 
> Many of these bugs have been in the kernel for quite some time, but
> Frederic's recent change now gives warnings.
> 
> This patch takes the straightforward approach of pushing the
> rcu_idle_enter()/rcu_idle_exit() pair further down into the core
> of the idle loop.
> 
> Signed-off-by: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> 

Oh well, just when I decided to sleep a bit, you send a new patch :)

This seems to remove the warnings at least on my x86_64 server, thanks !

Tested-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>



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