On Wed, Jul 23, 2014 at 09:23:47AM -0400, Pranith Kumar wrote: > On Wed, Jul 23, 2014 at 8:09 AM, Paul E. McKenney > <paul...@linux.vnet.ibm.com> wrote: > > On Wed, Jul 23, 2014 at 01:09:41AM -0400, Pranith Kumar wrote: > >> rcu_prcess_callbacks() is the softirq handler for RCU which is raised from > >> invoke_rcu_core() which is called from __call_rcu_core(). > >> > >> Each of these three functions checks if the cpu is online. We can remove > >> the > >> redundant ones. This commit removes one of these redundant check. > >> > >> Signed-off-by: Pranith Kumar <bobby.pr...@gmail.com> > > > > Sorry, but no. There can be a long delay between raise_softirq() and > > this function starting, particularly if ksoftirqd gets involved. The > > CPU could easily go offline in the meantime. > > > > That makes sense. I guess one of the other two checks in > __call_rcu_core() or invoke_rcu_core() can go then?
What would have to be the case for this suggested change to be safe? Does that condition in fact hold? Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/