On Mon, May 06, 2013 at 09:06:15PM -0700, Greg KH wrote: > On Tue, May 07, 2013 at 01:49:34PM +1000, Michael Ellerman wrote: > > From: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx> > > > > Commit 7122beeee7bc1757682049780179d7c216dd1c83 upstream. > > > > The following commit breaks numa distance setup for old powerpc > > systems that use form0 encoding in device tree. > > > > commit 41eab6f88f24124df89e38067b3766b7bef06ddb > > powerpc/numa: Use form 1 affinity to setup node distance > > > > Device tree node /rtas/ibm,associativity-reference-points would > > index into /cpus/PowerPCxxxx/ibm,associativity based on form0 or > > form1 encoding detected by ibm,architecture-vec-5 property. > > > > All modern systems use form1 and current kernel code is correct. > > However, on older systems with form0 encoding, the numa distance > > will get hard coded as LOCAL_DISTANCE for all nodes. This causes > > task scheduling anomaly since scheduler will skip building numa > > level domain (topmost domain with all cpus) if all numa distances > > are same. (value of 'level' in sched_init_numa() will remain 0) > > > > Prior to the above commit: > > ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE) > > > > Restoring compatible behavior with this patch for old powerpc systems > > with device tree where numa distance are encoded as form0. > > > > Signed-off-by: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Michael Ellerman <michael@xxxxxxxxxxxxxx> > > --- > > arch/powerpc/mm/numa.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > What stable tree should this be applied to? All of them please. cheers -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html