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| author | Jan Beulich <jbeulich@novell.com> | 2007-07-15 23:41:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:47 -0700 |
| commit | 8b3b295502444340dd0701855ac422fbf32e161d (patch) | |
| tree | 949accf30a7b8bf6a0ccd074a5a4b9f6115c1f7b | |
| parent | 98c0d07cbf2a8582a0341b05ad564247e608f6f9 (diff) | |
| download | linux-8b3b295502444340dd0701855ac422fbf32e161d.tar.gz linux-8b3b295502444340dd0701855ac422fbf32e161d.tar.bz2 linux-8b3b295502444340dd0701855ac422fbf32e161d.zip | |
adjust nosmp handling
Especially when !CONFIG_HOTPLUG_CPU, avoid needlessy allocating resources for
CPUs that can never become available.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | init/main.c | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/init/main.c b/init/main.c index c8c9a0b21e99..d3bcb3b11620 100644 --- a/init/main.c +++ b/init/main.c @@ -132,20 +132,9 @@ static char *static_command_line; static char *execute_command; static char *ramdisk_execute_command; +#ifdef CONFIG_SMP /* Setup configured maximum number of CPUs to activate */ -static unsigned int max_cpus = NR_CPUS; - -/* - * If set, this is an indication to the drivers that reset the underlying - * device before going ahead with the initialization otherwise driver might - * rely on the BIOS and skip the reset operation. - * - * This is useful if kernel is booting in an unreliable environment. - * For ex. kdump situaiton where previous kernel has crashed, BIOS has been - * skipped and devices will be in unknown state. - */ -unsigned int reset_devices; -EXPORT_SYMBOL(reset_devices); +static unsigned int __initdata max_cpus = NR_CPUS; /* * Setup routine for controlling SMP activation @@ -160,10 +149,10 @@ EXPORT_SYMBOL(reset_devices); static int __init nosmp(char *str) { max_cpus = 0; - return 1; + return 0; } -__setup("nosmp", nosmp); +early_param("nosmp", nosmp); static int __init maxcpus(char *str) { @@ -172,6 +161,21 @@ static int __init maxcpus(char *str) } __setup("maxcpus=", maxcpus); +#else +#define max_cpus NR_CPUS +#endif + +/* + * If set, this is an indication to the drivers that reset the underlying + * device before going ahead with the initialization otherwise driver might + * rely on the BIOS and skip the reset operation. + * + * This is useful if kernel is booting in an unreliable environment. + * For ex. kdump situaiton where previous kernel has crashed, BIOS has been + * skipped and devices will be in unknown state. + */ +unsigned int reset_devices; +EXPORT_SYMBOL(reset_devices); static int __init set_reset_devices(char *str) { @@ -385,6 +389,10 @@ static void __init smp_init(void) { unsigned int cpu; +#ifndef CONFIG_HOTPLUG_CPU + cpu_possible_map = cpu_present_map; +#endif + /* FIXME: This should be done in userspace --RR */ for_each_present_cpu(cpu) { if (num_online_cpus() >= max_cpus) @@ -529,6 +537,10 @@ asmlinkage void __init start_kernel(void) setup_arch(&command_line); setup_command_line(command_line); unwind_setup(); +#ifndef CONFIG_HOTPLUG_CPU + if (max_cpus < 2) + cpu_possible_map = cpu_online_map; +#endif setup_per_cpu_areas(); smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ |