Resending to the list due to mailer/html issues. On Sun, Nov 2, 2014 at 8:30 AM, Mike Galbraith <umgwanakikbuti@xxxxxxxxx> wrote: > > On Fri, 2014-10-31 at 17:03 -0400, Steven Rostedt wrote: > > Dear RT Folks, > > > > I'm pleased to announce the 3.14.23-rt20 stable release. > > > > This is the first 3.14-rt release in the stable-rt series. Normally I > > wait till the next development release is out before I pull in a new > > one. That is, I would pull in 3.14-rt when 3.16-rt or later was > > released. But because development is now moving at a "hobbyist rate" > > (read http://lwn.net/Articles/617140/ for details) > > and 3.14-rt is no longer being developed against, I figured it was > > time > > to put it under the "stable-rt" umbrella. > > I piddled about with it yesterday, found that you can't change cpufreq > governor IFF the tree is configured as rt, but works fine as voluntary > preempt. The problem seems to be this patch: https://lkml.org/lkml/2014/4/8/584 The cpufreq code does nested down_read_trylocks and only the first one succeeds: drivers/cpufreq/cpufreq.c: store down_read_trylock(cpufreq_rwsem) <- succeeds store_scaling_governor cpufreq_get_policy cpufreq_cpu_get down_read_trylock(cpufreq_rwsem) <-- fails Reverting the above patch 'fixes' the problem. I don't understand Steven's commit comment that readers of rwsem are not allowed to nest in mainline since this works just fine in mainline. ...Juerg > I'll poke about for the entertainment value. Having no > personal need/use for rt detracts from its hobby value somewhat, but rt > problems do have a tendency to be 'entertaining'. > > I'll follow up with a few patches that folks can apply to their trees if > they so desire. There being no devel tree to submit against, I can't do > a proper submission (rules), and some of them you surely don't want :) > > -Mike -- 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
