From 88a2a4ac6b671a4b0dd5d2d762418904c05f4104 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 4 Feb 2006 23:27:36 -0800 Subject: [PATCH] percpu data: only iterate over possible CPUs percpu_data blindly allocates bootmem memory to store NR_CPUS instances of cpudata, instead of allocating memory only for possible cpus. As a preparation for changing that, we need to convert various 0 -> NR_CPUS loops to use for_each_cpu(). (The above only applies to users of asm-generic/percpu.h. powerpc has gone it alone and is presently only allocating memory for present CPUs, so it's currently corrupting memory). Signed-off-by: Eric Dumazet Cc: "David S. Miller" Cc: James Bottomley Acked-by: Ingo Molnar Cc: Jens Axboe Cc: Anton Blanchard Acked-by: William Irwin Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 44b4eb4202d9..dde04ff4be31 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1213,18 +1213,21 @@ static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask) { int cpu = 0; - memset(ret, 0, sizeof(*ret)); + memset(ret, 0, nr * sizeof(unsigned long)); cpus_and(*cpumask, *cpumask, cpu_online_map); cpu = first_cpu(*cpumask); while (cpu < NR_CPUS) { unsigned long *in, *out, off; + if (!cpu_isset(cpu, *cpumask)) + continue; + in = (unsigned long *)&per_cpu(page_states, cpu); cpu = next_cpu(cpu, *cpumask); - if (cpu < NR_CPUS) + if (likely(cpu < NR_CPUS)) prefetch(&per_cpu(page_states, cpu)); out = (unsigned long *)ret; @@ -1886,8 +1889,7 @@ static void setup_pagelist_highmark(struct per_cpu_pageset *p, * not check if the processor is online before following the pageset pointer. * Other parts of the kernel may not check if the zone is available. */ -static struct per_cpu_pageset - boot_pageset[NR_CPUS]; +static struct per_cpu_pageset boot_pageset[NR_CPUS]; /* * Dynamically allocate memory for the -- cgit v1.2.2