SLUB now requires a portion of the per cpu reserve. There are on average about 70 real slabs on a system (aliases do not count) and each needs 12 bytes of per cpu space. Thats 840 bytes. In debug mode all slabs will be real slabs which will make us end up with 150 -> 1800. Things work fine without this patch but then slub will reduce the percpu reserve for modules. Percpu data must be available regardless if modules are in use or not. So get rid of the #ifdef CONFIG_MODULES. Make the size of the percpu area dependant on the size of a machine word. That way we have larger sizes for 64 bit machines. 64 bit machines need more percpu memory since the pointer and counters may have double the size. Plus there is lots of memory available on 64 bit. Signed-off-by: Christoph Lameter Index: linux-2.6/include/linux/percpu.h =================================================================== --- linux-2.6.orig/include/linux/percpu.h 2008-11-05 12:05:46.000000000 -0600 +++ linux-2.6/include/linux/percpu.h 2008-11-05 14:29:15.000000000 -0600 @@ -44,7 +44,7 @@ extern unsigned int percpu_reserve; /* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */ #ifndef PERCPU_AREA_SIZE -#define PERCPU_RESERVE_SIZE 8192 +#define PERCPU_RESERVE_SIZE (sizeof(unsigned long) * 2500) #define PERCPU_AREA_SIZE \ (__per_cpu_end - __per_cpu_start + percpu_reserve) -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/