Messages in this thread | | | Date | Mon, 10 May 2004 09:54:04 -0500 | From | Matt Mackall <> | Subject | Re: dentry bloat. |
| |
On Mon, May 10, 2004 at 02:46:58AM -0700, Andrew Morton wrote: > Arjan van de Ven <arjanv@redhat.com> wrote: > > > > On Mon, 2004-05-10 at 10:27, Helge Hafting wrote: > > > Matt Mackall wrote: > > > > > > >One also wonders about whether all the RCU stuff is needed on UP. I'm > > > >not sure if I grok all the finepoints here, but it looks like the > > > >answer is no and that we can make struct_rcu head empty and have > > > >call_rcu fall directly through to the callback. This would save > > > >something like 16-32 bytes (32/64bit), not to mention a bunch of > > > >dinking around with lists and whatnot. > > > > > > > >So what am I missing? > > > > > > > > > > > Preempt can happen anytime, I believe. > > > > ok so for UP-non-preempt we can still get those 16 bytes back from the > > dentry.... > > I suppose so. And on small SMP, really. We chose not to play those games > early on so the code got the best testing coverage.
Ok, I can spin something up. I'll start with a generic no-RCU-on-UP and then we can think about the small SMP case a bit later.
-- Matt Mackall : http://www.selenic.com : Linux development and consulting - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |