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authorEric Dumazet <dada1@cosmosbay.com>2006-03-23 03:01:04 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-23 07:38:17 -0800
commit63872f87a151413100678f110d1556026002809e (patch)
tree4abb8b8c7f60a9d2c6645c4eb9e95a9c6ba56023
parent5a6b7951bfcca7f45f44269ea87417c74558daf8 (diff)
[PATCH] Only allocate percpu data for possible CPUs
percpu_data blindly allocates bootmem memory to store NR_CPUS instances of cpudata, instead of allocating memory only for possible cpus. This patch saves ram, allocating num_possible_cpus() (instead of NR_CPUS) instances. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: "David S. Miller" <davem@davemloft.net> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Jens Axboe <axboe@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <axboe@suse.de> Cc: Anton Blanchard <anton@samba.org> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--init/main.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/init/main.c b/init/main.c
index 141e8896d25..9cf6b307bfd 100644
--- a/init/main.c
+++ b/init/main.c
@@ -333,6 +333,7 @@ static void __init setup_per_cpu_areas(void)
{
unsigned long size, i;
char *ptr;
+ unsigned long nr_possible_cpus = num_possible_cpus();
/* Copy section for each CPU (we discard the original) */
size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
@@ -340,12 +341,16 @@ static void __init setup_per_cpu_areas(void)
if (size < PERCPU_ENOUGH_ROOM)
size = PERCPU_ENOUGH_ROOM;
#endif
+ ptr = alloc_bootmem(size * nr_possible_cpus);
- ptr = alloc_bootmem(size * NR_CPUS);
-
- for (i = 0; i < NR_CPUS; i++, ptr += size) {
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_possible(i)) {
+ __per_cpu_offset[i] = (char*)0 - __per_cpu_start;
+ continue;
+ }
__per_cpu_offset[i] = ptr - __per_cpu_start;
memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+ ptr += size;
}
}
#endif /* !__GENERIC_PER_CPU */