Messages in this thread | | | Subject | Re: [PATCH][RESEND] scalable rw_mutex | From | Peter Zijlstra <> | Date | Fri, 08 Aug 2008 16:15:23 +0200 |
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A: http://en.wikipedia.org/wiki/Top_post Q: Were do I find info about this thing called top-posting? A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing?
On Fri, 2008-08-08 at 10:04 -0400, Ryan Hope wrote: > Sorry for not CCing you, I had intended to CC you and others but I > clicked send too quick. One of the reiser4 todo's was remove all > semaphore's, I didnt realize rw_semaphores were not real semaphores
Yeah, more people make that mistake. They're basically a sleeping rw lock and already conform to the semantics that are required for lockdep and are thus also already covered by lockdep.
> On Fri, Aug 8, 2008 at 6:21 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Thu, 2008-08-07 at 18:56 -0400, Ryan Hope wrote: > >> This was posted sometime last year I think and it never got merged. Can this get > >> a go around in -mm, it would help in converting the semaphore's in reiser4 to > >> mutexes. > > > > Thanks for CC'ing me :-/ > > > > I dropped it because its only more scalable up to around 4 cpus. > > > > Also, how would it help reiser4? using rwsems is perfectly fine - as > > they aren't actual semaphores.
<snip code>
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