From: Vernon Mauery <vernux@xxxxxxxxxx> Date: Wed, 18 Mar 2009 14:10:33 -0700 > David Miller wrote: > > From: Andi Kleen <andi@xxxxxxxxxxxxxx> > > Date: Wed, 18 Mar 2009 21:54:37 +0100 > > > >> But then again I'm not sure it's worth it if the problem only > >> happens in out of tree RT. > > The list of problems that only show up with the RT kernel seems to be > > constantly increasing, but honestly is very surprising to me. > > I don't understand why we even need to be concerned about this stuff > > upstream, to be honest. > > Please reproduce this in the vanilla kernel, then get back to us. > > Huh? The numbers that I posted *were* from the vanilla kernel. I ran > the 2.6.29-rc8 kernel with lock_stat enabled. The lock contention > happens on the same lock in both vanilla and -rt, it just happens > to be more pronounced in the -rt kernel because of the double context > switches that the sleeping spinlock/rt-mutexes introduce. And the double context switches are probably also why less natural batching and locality are achieved in the RT kernel. Isn't that true? -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
