On Fri, 2010-04-16 at 13:33 -0700, Andrew Morton wrote: > On Thu, 15 Apr 2010 13:29:56 -0400 > Lee Schermerhorn <lee.schermerhorn@xxxxxx> wrote: > > > Rework the generic version of the numa_node_id() function to use the > > new generic percpu variable infrastructure. > > > > Guard the new implementation with a new config option: > > > > CONFIG_USE_PERCPU_NUMA_NODE_ID. > > > > Archs which support this new implemention will default this option > > to 'y' when NUMA is configured. This config option could be removed > > if/when all archs switch over to the generic percpu implementation > > of numa_node_id(). Arch support involves: > > > > 1) converting any existing per cpu variable implementations to use > > this implementation. x86_64 is an instance of such an arch. > > 2) archs that don't use a per cpu variable for numa_node_id() will > > need to initialize the new per cpu variable "numa_node" as cpus > > are brought on-line. ia64 is an example. > > 3) Defining USE_PERCPU_NUMA_NODE_ID in arch dependent Kconfig--e.g., > > when NUMA is configured. This is required because I have > > retained the old implementation by default to allow archs to > > be modified incrementally, as desired. > > > > Subsequent patches will convert x86_64 and ia64 to use this > > implemenation. > > So which arches _aren't_ converted? powerpc, sparc and alpha? Right. Plus ARM, mips, ... I could take a cut at other archs, but can't test them. I'm hoping that this patch doesn't break the existing implementation for them. It should be a no-op until the new support is enabled via Kconfig. The fact that both x86_64 and ia64 build with just this patch gives me some hope but not a lot of confidence. I see that you've merged the series with into -mm. We'll see what happens. Of course, no reports of errors could just mean no testing. > > Is there sufficient info here for the maintainers to be able to > perform the conversion with minimal head-scratching? Arch maintainers will need to chime in on that. I'd hoped that the list above and the examples of x86_64 and ia64 in the subsequent patches would suffice. Lee -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>