On Tue, Nov 20, 2012 at 05:06:01PM +0000, Robert Richter wrote: > On 20.11.12 16:55:17, Will Deacon wrote: > > On Tue, Nov 20, 2012 at 04:31:58PM +0000, Robert Richter wrote: > > > I am thinking of the following: > > > > > > # cat /root/cpu_type > > > arm/armv7-ca5 > > > # cat /dev/oprofile/cpu_type > > > unknown > > > # mount --bind /root/cpu_type /dev/oprofile/cpu_type > > > # cat /dev/oprofile/cpu_type > > > arm/armv7-ca5 > > > > > > From here legacy oprofile tools work as expected using oprofilefs. (I > > > think. Did not test it.) We need to change the kernel for this a bit > > > to return 'unknown'. The mount could be done by the oprofile tools > > > using existing cpu detection code. This is only one way to setup > > > cpu_type from userland, there could be other ways too. > > > > Ok, this is functionally equivalent to the patch that was submitted at the > > start of this thread: it solves the problem of mapping a single ARM core to > > a oprofile's CPU ID string. Technically, I don't mind doing that in the > > kernel (at least, it means you don't need to do your trick above) > > The advantage of a solution where userland updates cpu_type is that we > never need to update the kernel anymore. This means, cpu detection can > be part of the tools.
True, but the kernel-side perf code still needs updating to support the new CPU so I don't think you win much. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
