Messages in this thread | | | Date | Sun, 15 Apr 2012 09:25:37 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH RFC 0/7] rcu: v2 Inlinable preemptible rcu_read_lock() and rcu_read_unlock() |
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On Sat, Apr 14, 2012 at 10:25:04AM -0700, Paul E. McKenney wrote: > On Sat, Apr 14, 2012 at 10:08:54AM -0700, Linus Torvalds wrote: > > On Sat, Apr 14, 2012 at 9:58 AM, Linus Torvalds > > <torvalds@linux-foundation.org> wrote: > > > > > > I'll see if it boots and what it does to my profiles and > > > microbenchmark, though. > > > > Ok, I can't see any performance difference in the numbers - my > > benchmark noise is *much* bigger than anything this would show. > > Might still be worthwhile on embedded CPUs that don't optimize > function calls as thoroughly as does x86, maybe? > > > The profile looks fine, and obviously __rcu_read_lock() is entirely > > gone. The top user (avc_has_perm_flags()) looks fine. I note that you > > might want to look at the placement of the percpu data - I think it > > probably makes sense to put the RCU data close to 'current' etc to get > > as much cacheline sharing as possible, and it doesn't seem to be right > > now, but it looks reasonable. > > Is there somewhere in non-architecture-specific code that would be a > good place to put this? Or is the DEFINE_PER_CPU() for current_task > moving from arch/x86 to core code? > > > But on the whole, I can't claim that it looks noticeable ;*( > > Well, then, I guess I don't feel quite so bad about having prioritized > this so low for so long. ;-)
One other thing -- may I add your Tested-by to the series?
Thanx, Paul
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