diff options
| author | Mike Travis <travis@sgi.com> | 2008-12-18 00:21:39 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-18 12:08:05 +0100 |
| commit | 3b11ce7f542e415c90267b4482d4611410b468e6 (patch) | |
| tree | 26366b9f25af830b71c78504bbadd94896a8b82a /arch/x86/kernel/smpboot.c | |
| parent | x86: fix cpu_mask_to_apicid_and to include cpu_online_mask (diff) | |
| download | linux-3b11ce7f542e415c90267b4482d4611410b468e6.tar.xz linux-3b11ce7f542e415c90267b4482d4611410b468e6.zip | |
x86: use possible_cpus=NUM to extend the possible cpus allowed
Impact: add new boot parameter
Use possible_cpus=NUM kernel parameter to extend the number of possible
cpus.
The ability to HOTPLUG ON cpus that are "possible" but not "present" is
dealt with in a later patch.
Signed-off-by: Mike Travis <travis@sgi.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index be9466788043..1a9941b11150 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1252,6 +1252,15 @@ void __init native_smp_cpus_done(unsigned int max_cpus) check_nmi_watchdog(); } +static int __initdata setup_possible_cpus = -1; +static int __init _setup_possible_cpus(char *str) +{ + get_option(&str, &setup_possible_cpus); + return 0; +} +early_param("possible_cpus", _setup_possible_cpus); + + /* * cpu_possible_map should be static, it cannot change as cpu's * are onlined, or offlined. The reason is per-cpu data-structures @@ -1264,7 +1273,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus) * * Three ways to find out the number of additional hotplug CPUs: * - If the BIOS specified disabled CPUs in ACPI/mptables use that. - * - The user can overwrite it with additional_cpus=NUM + * - The user can overwrite it with possible_cpus=NUM * - Otherwise don't reserve additional CPUs. * We do this because additional CPUs waste a lot of memory. * -AK @@ -1277,9 +1286,17 @@ __init void prefill_possible_map(void) if (!num_processors) num_processors = 1; - possible = num_processors + disabled_cpus; - if (possible > NR_CPUS) - possible = NR_CPUS; + if (setup_possible_cpus == -1) + possible = num_processors + disabled_cpus; + else + possible = setup_possible_cpus; + + if (possible > CONFIG_NR_CPUS) { + printk(KERN_WARNING + "%d Processors exceeds NR_CPUS limit of %d\n", + possible, CONFIG_NR_CPUS); + possible = CONFIG_NR_CPUS; + } printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n", possible, max_t(int, possible - num_processors, 0)); |