smp: Use nr_cpus= to set nr_cpu_ids early
On x86, before prefill_possible_map(), nr_cpu_ids will be NR_CPUS aka
CONFIG_NR_CPUS.
Add nr_cpus= to set nr_cpu_ids. so we can simulate cpus <=8 are installed on
normal config.
-v2: accordging to Christoph, acpi_numa_init should use nr_cpu_ids in stead of
NR_CPUS.
-v3: add doc in kernel-parameters.txt according to Andrew.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-34-git-send-email-yinghai@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
diff --git a/init/main.c b/init/main.c
index 8451878..05b5283 100644
--- a/init/main.c
+++ b/init/main.c
@@ -149,6 +149,20 @@
early_param("nosmp", nosmp);
+/* this is hard limit */
+static int __init nrcpus(char *str)
+{
+ int nr_cpus;
+
+ get_option(&str, &nr_cpus);
+ if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
+ nr_cpu_ids = nr_cpus;
+
+ return 0;
+}
+
+early_param("nr_cpus", nrcpus);
+
static int __init maxcpus(char *str)
{
get_option(&str, &setup_max_cpus);