Hi Nicholas, On Sat, 2014-04-26 at 15:58 +0200, Mike Galbraith wrote: > On Sat, 2014-04-26 at 10:38 +0200, Mike Galbraith wrote: > > On Fri, 2014-04-25 at 09:40 +0200, Mike Galbraith wrote: > > > > > Hotplug can still deadlock in rt trees too, and will if you beat it > > > hard. > > > > Box actually deadlocks like so. > > ... > > 3.12-rt looks a bit busted migrate_disable/enable() wise. > > /me eyeballs 3.10-rt (looks better), confirms 3.10-rt hotplug works, > swipes working code, confirms 3.12-rt now works. Yup, that was it. My boxen, including 64 core DL980 that ran hotplug stress for 3 hours yesterday with pre-pushdown rwlocks, say the migrate_disable/enable pushdown patches are very definitely busted. Instead of whacking selective bits, as I did to verify that the rwlock changes were indeed causing hotplug stress deadlock woes, I'm eyeballing the lot, twiddling primitives to look like I think they should, after which I'll let my boxen express their opinions of the result. -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
