The per cpu reserve from which loadable modules allocate their percpu sections is currently fixed at 8000 bytes. Add a new kernel parameter percpu= The per cpu reserve area will be used in following patches by the per cpu allocator. Signed-off-by: Christoph Lameter --- arch/ia64/include/asm/percpu.h | 1 + include/linux/percpu.h | 7 ++++++- init/main.c | 13 +++++++++++++ 3 files changed, 20 insertions(+), 1 deletion(-) Index: linux-2.6/include/linux/percpu.h =================================================================== --- linux-2.6.orig/include/linux/percpu.h 2008-09-25 08:39:19.000000000 -0500 +++ linux-2.6/include/linux/percpu.h 2008-09-29 13:08:25.000000000 -0500 @@ -34,6 +34,7 @@ #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) +extern unsigned int percpu_reserve; /* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */ #ifndef PERCPU_ENOUGH_ROOM #ifdef CONFIG_MODULES @@ -43,7 +44,7 @@ #endif #define PERCPU_ENOUGH_ROOM \ - (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE) + (__per_cpu_end - __per_cpu_start + percpu_reserve) #endif /* PERCPU_ENOUGH_ROOM */ /* Index: linux-2.6/init/main.c =================================================================== --- linux-2.6.orig/init/main.c 2008-09-25 08:39:19.000000000 -0500 +++ linux-2.6/init/main.c 2008-09-29 13:09:13.000000000 -0500 @@ -253,6 +253,16 @@ early_param("loglevel", loglevel); +unsigned int percpu_reserve = PERCPU_MODULE_RESERVE; + +static int __init init_percpu_reserve(char *str) +{ + get_option(&str, &percpu_reserve); + return 0; +} + +early_param("percpu", init_percpu_reserve); + /* * Unknown boot options get handed to init, unless they look like * failed parameters @@ -397,6 +407,9 @@ /* Copy section for each CPU (we discard the original) */ size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE); + printk(KERN_INFO "percpu area: %d bytes total, %d available.\n", + size, size - (__per_cpu_end - __per_cpu_start)); + ptr = alloc_bootmem_pages(size * nr_possible_cpus); for_each_possible_cpu(i) { Index: linux-2.6/Documentation/kernel-parameters.txt =================================================================== --- linux-2.6.orig/Documentation/kernel-parameters.txt 2008-09-25 08:39:19.000000000 -0500 +++ linux-2.6/Documentation/kernel-parameters.txt 2008-09-29 13:05:36.000000000 -0500 @@ -1643,6 +1643,13 @@ Format: { 0 | 1 } See arch/parisc/kernel/pdc_chassis.c + percpu= Configure the number of percpu bytes that can be + dynamically allocated. This is used for per cpu + variables of modules and other dynamic per cpu data + structures. Creation of per cpu structures after boot + may fail if this is set too low. + Default is 8000 bytes. + pf. [PARIDE] See Documentation/paride.txt. -- -- 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/