On Fri, 2009-11-20 at 10:46 -0500, Christoph Lameter wrote: > On Fri, 13 Nov 2009, Lee Schermerhorn wrote: > > > Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx> > > [Christoph's signoff here?] > > Basically yes. The moving of the this_cpu ops to asm-generic is something > that is bothering me. Tejun? So here's what happened: linux/topology.h now depends on */percpu.h to implement numa_node_id() and numa_mem_id(). Not so much an issue for x86 because its asm/topology.h already depended on its asm/percpu.h. But ia64, for instance--maybe any arch that doesn't already implement numa_node_id() as a percpu variable--didn't define this_cpu_read() for linux/topology.h. So, I included <linux/percpu.h>. linux/percpu.h, for reasons of its own, includes linux/swap.h which includes linux/gfp.h which includes linux/topology.h for the definition of numa_node_id(). topology.h hasn't gotten around to defining numa_node_id() yet--it's still including percpu.h. ... Looking at other asm/foo.h and asm-generic/foo.h relationships, I see that some define the generic version of the api in the asm-generic header if the arch asm header hasn't already defined it. asm/topology.h is an instance of this. It includes asm-generic/topology.h after defining arch specific versions of some of the api. Following this model, I moved the generic definitions of the percpu api back to the asm-generic version where it would be available without the inclusion of swap.h, et al. I tried including <asm/percpu.h> in linux/topology.h but the was advised to use the generic header. So I followed the model of the x86 asm/topology.h and included asm/percpu.h in the ia64 asm/topology.h, making the definitions visible to linux/topology.h. This reminds me that I should add to the patch description a 3rd item required for an arch to use the generic percpu numa_node_id() implementation: make the percpu variable access interface visible via asm/topology.h. Does that sound reasonable? Lee -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
