On Thu, Jun 19, 2014 at 04:42:11PM -0400, Sasha Levin wrote: > On 06/19/2014 04:29 PM, Paul E. McKenney wrote: > > rcu: Provide call_rcu_alloc() and call_rcu_sched_alloc() to avoid recursion > > > > The sl*b allocators use call_rcu() to manage object lifetimes, but > > call_rcu() can use debug-objects, which in turn invokes the sl*b > > allocators. These allocators are not prepared for this sort of > > recursion, which can result in failures. > > > > This commit therefore creates call_rcu_alloc() and call_rcu_sched_alloc(), > > which act as their call_rcu() and call_rcu_sched() counterparts, but > > which avoid invoking debug-objects. These new API members are intended > > only for use by the sl*b allocators, and this commit makes the sl*b > > allocators use call_rcu_alloc(). Why call_rcu_sched_alloc()? Because > > in CONFIG_PREEMPT=n kernels, call_rcu() maps to call_rcu_sched(), so > > therefore call_rcu_alloc() must map to call_rcu_sched_alloc(). > > > > Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx> > > Set-straight-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > Paul, what is this patch based on? It won't apply cleanly on -next > or Linus's tree. On my -rcu tree, but I think that Thomas's approach is better. Thanx, Paul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>