[patch] Fix large MCA bootmem allocation The MCA code allocates bootmem memory for NR_CPUS, regardless of how many cpus the system actually has. This change allocates memory only for cpus that actually exist. On my test system with NR_CPUS = 1024, reserved memory was reduced by 130944k. Before: Memory: 27886976k/28111168k available (8282k code, 242304k reserved, 5928k data, 1792k init) After: Memory: 28017920k/28111168k available (8282k code, 111360k reserved, 5928k data, 1792k init) Signed-off-by: Russ Anderson <rja@xxxxxxx> --- arch/ia64/kernel/mca.c | 52 +++++++++++++++++++++---------------------------- 1 file changed, 23 insertions(+), 29 deletions(-) Index: test/arch/ia64/kernel/mca.c =================================================================== --- test.orig/arch/ia64/kernel/mca.c 2008-02-05 13:01:56.000000000 -0600 +++ test/arch/ia64/kernel/mca.c 2008-02-05 13:12:34.921332805 -0600 @@ -17,7 +17,7 @@ * Copyright (C) 2000 Intel * Copyright (C) Chuck Fleckenstein <cfleck@xxxxxxxxxxxx> * - * Copyright (C) 1999, 2004 Silicon Graphics, Inc. + * Copyright (C) 1999, 2004-2008 Silicon Graphics, Inc. * Copyright (C) Vijay Chander <vijay@xxxxxxxxxxxx> * * Copyright (C) 2006 FUJITSU LIMITED @@ -1762,11 +1762,8 @@ format_mca_init_stack(void *mca_data, un /* Caller prevents this from being called after init */ static void * __init_refok mca_bootmem(void) { - void *p; - - p = alloc_bootmem(sizeof(struct ia64_mca_cpu) * NR_CPUS + - KERNEL_STACK_SIZE); - return (void *)ALIGN((unsigned long)p, KERNEL_STACK_SIZE); + return __alloc_bootmem(sizeof(struct ia64_mca_cpu), + KERNEL_STACK_SIZE, 0); } /* Do per-CPU MCA-related initialization. */ @@ -1774,33 +1771,30 @@ void __cpuinit ia64_mca_cpu_init(void *cpu_data) { void *pal_vaddr; + void *data; + long sz = sizeof(struct ia64_mca_cpu); + int cpu = smp_processor_id(); static int first_time = 1; - if (first_time) { - void *mca_data; - int cpu; - - first_time = 0; - mca_data = mca_bootmem(); - for (cpu = 0; cpu < NR_CPUS; cpu++) { - format_mca_init_stack(mca_data, - offsetof(struct ia64_mca_cpu, mca_stack), - "MCA", cpu); - format_mca_init_stack(mca_data, - offsetof(struct ia64_mca_cpu, init_stack), - "INIT", cpu); - __per_cpu_mca[cpu] = __pa(mca_data); - mca_data += sizeof(struct ia64_mca_cpu); - } - } - /* - * The MCA info structure was allocated earlier and its - * physical address saved in __per_cpu_mca[cpu]. Copy that - * address * to ia64_mca_data so we can access it as a per-CPU - * variable. + * Structure will already be allocated if cpu has been online, + * then offlined. */ - __get_cpu_var(ia64_mca_data) = __per_cpu_mca[smp_processor_id()]; + if (__per_cpu_mca[cpu]) { + data = __va(__per_cpu_mca[cpu]); + } else { + if (first_time) { + data = mca_bootmem(); + first_time = 0; + } else + data = page_address(alloc_pages_node(numa_node_id(), + GFP_KERNEL, get_order(sz))); + } + format_mca_init_stack(data, offsetof(struct ia64_mca_cpu, mca_stack), + "MCA", cpu); + format_mca_init_stack(data, offsetof(struct ia64_mca_cpu, init_stack), + "INIT", cpu); + __get_cpu_var(ia64_mca_data) = __per_cpu_mca[cpu] = __pa(data); /* * Stash away a copy of the PTE needed to map the per-CPU page. -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@xxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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