On Wed, Aug 31, 2011 at 07:19:33PM +0100, Rob Herring wrote: > On 08/31/2011 12:51 PM, Will Deacon wrote: > > Another thing that Marc and I tried on OMAP4 was not bringing up the secondary > > CPU during boot (by commenting out most of smp_init). In this case, I/O > > performance was good until we tried to online the secondary CPU. The online > > failed but after that the I/O performance was certainly degraded. > > > > Was the SCU enabled at that point? One diff between nosmp boot and > offlining the 2nd core would be that the SCU remains enabled in the > latter case. I think the SCU does not get enabled for nosmp. Our rudimentary test (printing out the SCU control register during boot) showed that it *was* enabled for nosmp. I think this is due to the secure world having to do that on OMAP so it's probably not true for other platforms. Will -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html