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cpumask: centralize cpu_online_map and cpu_possible_map 

Impact: cleanup

Each SMP arch defines these themselves.  Move them to a central
location.

Twists:
1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a
   CONFIG_INIT_ALL_POSSIBLE for this rather than break them.

2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'.
   Those archs simply have phys_cpu_present_map replaced everywhere.

3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky
   so I just manipulate them both in sync.

4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map'
   declarations.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
Cc: ink@jurassic.park.msu.ru
Cc: rmk@arm.linux.org.uk
Cc: starvik@axis.com
Cc: tony.luck@intel.com
Cc: takata@linux-m32r.org
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: paulus@samba.org
Cc: schwidefsky@de.ibm.com
Cc: lethal@linux-sh.org
Cc: wli@holomorphy.com
Cc: davem@davemloft.net
Cc: jdike@addtoit.com
Cc: mingo@redhat.com
This commit is contained in:
Rusty Russell 2008-12-13 21:19:41 +10:30
parent 6c34bc2976
commit 98a79d6a50
35 changed files with 42 additions and 132 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/alpha/include/asm/smp.h
View File

@ -45,7 +45,6 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS];
#define raw_smp_processor_id() (current_thread_info()->cpu)
extern int smp_num_cpus;
#define cpu_possible_map cpu_present_map
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi(cpumask_t mask);

2
arch/alpha/kernel/process.c
View File

@ -94,6 +94,7 @@ common_shutdown_1(void *generic_ptr)
flags |= 0x00040000UL; /* "remain halted" */
*pflags = flags;
cpu_clear(cpuid, cpu_present_map);
cpu_clear(cpuid, cpu_possible_map);
halt();
}
#endif
@ -120,6 +121,7 @@ common_shutdown_1(void *generic_ptr)
#ifdef CONFIG_SMP
/* Wait for the secondaries to halt. */
cpu_clear(boot_cpuid, cpu_present_map);
cpu_clear(boot_cpuid, cpu_possible_map);
while (cpus_weight(cpu_present_map))
barrier();
#endif

7
arch/alpha/kernel/smp.c
View File

@ -70,11 +70,6 @@ enum ipi_message_type {
/* Set to a secondary's cpuid when it comes online. */
static int smp_secondary_alive __devinitdata = 0;
/* Which cpus ids came online. */
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
int smp_num_probed; /* Internal processor count */
int smp_num_cpus = 1; /* Number that came online. */
EXPORT_SYMBOL(smp_num_cpus);
@ -440,6 +435,7 @@ setup_smp(void)
((char *)cpubase + i*hwrpb->processor_size);
if ((cpu->flags & 0x1cc) == 0x1cc) {
smp_num_probed++;
cpu_set(i, cpu_possible_map);
cpu_set(i, cpu_present_map);
cpu->pal_revision = boot_cpu_palrev;
}
@ -473,6 +469,7 @@ smp_prepare_cpus(unsigned int max_cpus)
/* Nothing to do on a UP box, or when told not to. */
if (smp_num_probed == 1 || max_cpus == 0) {
cpu_possible_map = cpumask_of_cpu(boot_cpuid);
cpu_present_map = cpumask_of_cpu(boot_cpuid);
printk(KERN_INFO "SMP mode deactivated.\n");
return;

10
arch/arm/kernel/smp.c
View File

@ -33,16 +33,6 @@
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
/*
* bitmask of present and online CPUs.
* The present bitmask indicates that the CPU is physically present.
* The online bitmask indicates that the CPU is up and running.
*/
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
/*
* as from 2.5, kernels no longer have an init_tasks structure
* so we need some other way of telling a new secondary core

4
arch/cris/arch-v32/kernel/smp.c
View File

@ -29,11 +29,7 @@
spinlock_t cris_atomic_locks[] = { [0 ... LOCK_COUNT - 1] = SPIN_LOCK_UNLOCKED};
/* CPU masks */
cpumask_t cpu_online_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
EXPORT_SYMBOL(phys_cpu_present_map);
/* Variables used during SMP boot */

1
arch/cris/include/asm/smp.h
View File

@ -4,7 +4,6 @@
#include <linux/cpumask.h>
extern cpumask_t phys_cpu_present_map;
extern cpumask_t cpu_possible_map;
#define raw_smp_processor_id() (current_thread_info()->cpu)

1
arch/ia64/include/asm/smp.h
View File

@ -57,7 +57,6 @@ extern struct smp_boot_data {
extern char no_int_routing __devinitdata;
extern cpumask_t cpu_online_map;
extern cpumask_t cpu_core_map[NR_CPUS];
DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
extern int smp_num_siblings;

6
arch/ia64/kernel/smpboot.c
View File

@ -131,12 +131,6 @@ struct task_struct *task_for_booting_cpu;
*/
DEFINE_PER_CPU(int, cpu_state);
/* Bitmasks of currently online, and possible CPUs */
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_possible_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_possible_map);
cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_core_map);
DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);

1
arch/m32r/Kconfig
View File

@ -10,6 +10,7 @@ config M32R
default y
select HAVE_IDE
select HAVE_OPROFILE
select INIT_ALL_POSSIBLE
config SBUS
bool

6
arch/m32r/kernel/smpboot.c
View File

@ -73,17 +73,11 @@ static unsigned int bsp_phys_id = -1;
/* Bitmask of physically existing CPUs */
physid_mask_t phys_cpu_present_map;
/* Bitmask of currently online CPUs */
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_bootout_map;
cpumask_t cpu_bootin_map;
static cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
EXPORT_SYMBOL(cpu_callout_map);
cpumask_t cpu_possible_map = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_possible_map);
/* Per CPU bogomips and other parameters */
struct cpuinfo_m32r cpu_data[NR_CPUS] __cacheline_aligned;

3
arch/mips/include/asm/smp.h
View File

@ -38,9 +38,6 @@ extern int __cpu_logical_map[NR_CPUS];
#define SMP_RESCHEDULE_YOURSELF 0x1 /* XXX braindead */
#define SMP_CALL_FUNCTION 0x2
extern cpumask_t phys_cpu_present_map;
#define cpu_possible_map phys_cpu_present_map
extern void asmlinkage smp_bootstrap(void);
/*

2
arch/mips/kernel/smp-cmp.c
View File

@ -226,7 +226,7 @@ void __init cmp_smp_setup(void)
for (i = 1; i < NR_CPUS; i++) {
if (amon_cpu_avail(i)) {
cpu_set(i, phys_cpu_present_map);
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++ncpu;
__cpu_logical_map[ncpu] = i;
}

2
arch/mips/kernel/smp-mt.c
View File

@ -70,7 +70,7 @@ static unsigned int __init smvp_vpe_init(unsigned int tc, unsigned int mvpconf0,
write_vpe_c0_vpeconf0(tmp);
/* Record this as available CPU */
cpu_set(tc, phys_cpu_present_map);
cpu_set(tc, cpu_possible_map);
__cpu_number_map[tc] = ++ncpu;
__cpu_logical_map[ncpu] = tc;
}

7
arch/mips/kernel/smp.c
View File

@ -44,15 +44,10 @@
#include <asm/mipsmtregs.h>
#endif /* CONFIG_MIPS_MT_SMTC */
cpumask_t phys_cpu_present_map; /* Bitmask of available CPUs */
volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */
cpumask_t cpu_online_map; /* Bitmask of currently online CPUs */
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
EXPORT_SYMBOL(phys_cpu_present_map);
EXPORT_SYMBOL(cpu_online_map);
extern void cpu_idle(void);
/* Number of TCs (or siblings in Intel speak) per CPU core */
@ -195,7 +190,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
/* preload SMP state for boot cpu */
void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(0, phys_cpu_present_map);
cpu_set(0, cpu_possible_map);
cpu_set(0, cpu_online_map);
cpu_set(0, cpu_callin_map);
}

6
arch/mips/kernel/smtc.c
View File

@ -290,7 +290,7 @@ static void smtc_configure_tlb(void)
* possibly leave some TCs/VPEs as "slave" processors.
*
* Use c0_MVPConf0 to find out how many TCs are available, setting up
* phys_cpu_present_map and the logical/physical mappings.
* cpu_possible_map and the logical/physical mappings.
*/
int __init smtc_build_cpu_map(int start_cpu_slot)
@ -304,7 +304,7 @@ int __init smtc_build_cpu_map(int start_cpu_slot)
*/
ntcs = ((read_c0_mvpconf0() & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
for (i=start_cpu_slot; i<NR_CPUS && i<ntcs; i++) {
cpu_set(i, phys_cpu_present_map);
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}
@ -521,7 +521,7 @@ void smtc_prepare_cpus(int cpus)
* Pull any physically present but unused TCs out of circulation.
*/
while (tc < (((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1)) {
cpu_clear(tc, phys_cpu_present_map);
cpu_clear(tc, cpu_possible_map);
cpu_clear(tc, cpu_present_map);
tc++;
}

6
arch/mips/pmc-sierra/yosemite/smp.c
View File

@ -141,7 +141,7 @@ static void __cpuinit yos_boot_secondary(int cpu, struct task_struct *idle)
}
/*
* Detect available CPUs, populate phys_cpu_present_map before smp_init
* Detect available CPUs, populate cpu_possible_map before smp_init
*
* We don't want to start the secondary CPU yet nor do we have a nice probing
* feature in PMON so we just assume presence of the secondary core.
@ -150,10 +150,10 @@ static void __init yos_smp_setup(void)
{
int i;
cpus_clear(phys_cpu_present_map);
cpus_clear(cpu_possible_map);
for (i = 0; i < 2; i++) {
cpu_set(i, phys_cpu_present_map);
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}

2
arch/mips/sgi-ip27/ip27-smp.c
View File

@ -76,7 +76,7 @@ static int do_cpumask(cnodeid_t cnode, nasid_t nasid, int highest)
/* Only let it join in if it's marked enabled */
if ((acpu->cpu_info.flags & KLINFO_ENABLE) &&
(tot_cpus_found != NR_CPUS)) {
cpu_set(cpuid, phys_cpu_present_map);
cpu_set(cpuid, cpu_possible_map);
alloc_cpupda(cpuid, tot_cpus_found);
cpus_found++;
tot_cpus_found++;

8
arch/mips/sibyte/bcm1480/smp.c
View File

@ -136,7 +136,7 @@ static void __cpuinit bcm1480_boot_secondary(int cpu, struct task_struct *idle)
/*
* Use CFE to find out how many CPUs are available, setting up
* phys_cpu_present_map and the logical/physical mappings.
* cpu_possible_map and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
@ -145,14 +145,14 @@ static void __init bcm1480_smp_setup(void)
{
int i, num;
cpus_clear(phys_cpu_present_map);
cpu_set(0, phys_cpu_present_map);
cpus_clear(cpu_possible_map);
cpu_set(0, cpu_possible_map);
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
cpu_set(i, phys_cpu_present_map);
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}

8
arch/mips/sibyte/sb1250/smp.c
View File

@ -124,7 +124,7 @@ static void __cpuinit sb1250_boot_secondary(int cpu, struct task_struct *idle)
/*
* Use CFE to find out how many CPUs are available, setting up
* phys_cpu_present_map and the logical/physical mappings.
* cpu_possible_map and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
@ -133,14 +133,14 @@ static void __init sb1250_smp_setup(void)
{
int i, num;
cpus_clear(phys_cpu_present_map);
cpu_set(0, phys_cpu_present_map);
cpus_clear(cpu_possible_map);
cpu_set(0, cpu_possible_map);
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
cpu_set(i, phys_cpu_present_map);
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}

1
arch/parisc/Kconfig
View File

@ -11,6 +11,7 @@ config PARISC
select HAVE_OPROFILE
select RTC_CLASS
select RTC_DRV_PARISC
select INIT_ALL_POSSIBLE
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
in many of their workstations & servers (HP9000 700 and 800 series,

15
arch/parisc/kernel/smp.c
View File

@ -67,21 +67,6 @@ static volatile int cpu_now_booting __read_mostly = 0; /* track which CPU is boo
static int parisc_max_cpus __read_mostly = 1;
/* online cpus are ones that we've managed to bring up completely
* possible cpus are all valid cpu
* present cpus are all detected cpu
*
* On startup we bring up the "possible" cpus. Since we discover
* CPUs later, we add them as hotplug, so the possible cpu mask is
* empty in the beginning.
*/
cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE; /* Bitmap of online CPUs */
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; /* Bitmap of Present CPUs */
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
DEFINE_PER_CPU(spinlock_t, ipi_lock) = SPIN_LOCK_UNLOCKED;
enum ipi_message_type {

4
arch/powerpc/kernel/smp.c
View File

@ -60,13 +60,9 @@
int smp_hw_index[NR_CPUS];
struct thread_info *secondary_ti;
cpumask_t cpu_possible_map = CPU_MASK_NONE;
cpumask_t cpu_online_map = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
EXPORT_PER_CPU_SYMBOL(cpu_core_map);

1
arch/s390/Kconfig
View File

@ -75,6 +75,7 @@ config S390
select HAVE_KRETPROBES
select HAVE_KVM if 64BIT
select HAVE_ARCH_TRACEHOOK
select INIT_ALL_POSSIBLE
source "init/Kconfig"

6
arch/s390/kernel/smp.c
View File

@ -52,12 +52,6 @@
struct _lowcore *lowcore_ptr[NR_CPUS];
EXPORT_SYMBOL(lowcore_ptr);
cpumask_t cpu_online_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_possible_map = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_possible_map);
static struct task_struct *current_set[NR_CPUS];
static u8 smp_cpu_type;

6
arch/sh/kernel/smp.c
View File

@ -31,12 +31,6 @@
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
static inline void __init smp_store_cpu_info(unsigned int cpu)
{
struct sh_cpuinfo *c = cpu_data + cpu;

2
arch/sparc/include/asm/smp_32.h
View File

@ -29,8 +29,6 @@
*/
extern unsigned char boot_cpu_id;
extern cpumask_t phys_cpu_present_map;
#define cpu_possible_map phys_cpu_present_map
typedef void (*smpfunc_t)(unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long);

6
arch/sparc/kernel/smp.c
View File

@ -39,8 +39,6 @@ volatile unsigned long cpu_callin_map[NR_CPUS] __cpuinitdata = {0,};
unsigned char boot_cpu_id = 0;
unsigned char boot_cpu_id4 = 0; /* boot_cpu_id << 2 */
cpumask_t cpu_online_map = CPU_MASK_NONE;
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
cpumask_t smp_commenced_mask = CPU_MASK_NONE;
/* The only guaranteed locking primitive available on all Sparc
@ -334,7 +332,7 @@ void __init smp_setup_cpu_possible_map(void)
instance = 0;
while (!cpu_find_by_instance(instance, NULL, &mid)) {
if (mid < NR_CPUS) {
cpu_set(mid, phys_cpu_present_map);
cpu_set(mid, cpu_possible_map);
cpu_set(mid, cpu_present_map);
}
instance++;
@ -354,7 +352,7 @@ void __init smp_prepare_boot_cpu(void)
current_thread_info()->cpu = cpuid;
cpu_set(cpuid, cpu_online_map);
cpu_set(cpuid, phys_cpu_present_map);
cpu_set(cpuid, cpu_possible_map);
}
int __cpuinit __cpu_up(unsigned int cpu)

4
arch/sparc/kernel/sparc_ksyms.c
View File

@ -113,10 +113,6 @@ EXPORT_PER_CPU_SYMBOL(__cpu_data);
#ifdef CONFIG_SMP
/* IRQ implementation. */
EXPORT_SYMBOL(synchronize_irq);
/* CPU online map and active count. */
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(phys_cpu_present_map);
#endif
EXPORT_SYMBOL(__udelay);

4
arch/sparc64/kernel/smp.c
View File

@ -49,14 +49,10 @@
int sparc64_multi_core __read_mostly;
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_NONE;
cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
cpumask_t cpu_core_map[NR_CPUS] __read_mostly =
{ [0 ... NR_CPUS-1] = CPU_MASK_NONE };
EXPORT_SYMBOL(cpu_possible_map);
EXPORT_SYMBOL(cpu_online_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
EXPORT_SYMBOL(cpu_core_map);

7
arch/um/kernel/smp.c
View File

@ -25,13 +25,6 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
#include "irq_user.h"
#include "os.h"
/* CPU online map, set by smp_boot_cpus */
cpumask_t cpu_online_map = CPU_MASK_NONE;
cpumask_t cpu_possible_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
/* Per CPU bogomips and other parameters
* The only piece used here is the ipi pipe, which is set before SMP is
* started and never changed.

6
arch/x86/kernel/smpboot.c
View File

@ -101,14 +101,8 @@ EXPORT_SYMBOL(smp_num_siblings);
/* Last level cache ID of each logical CPU */
DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
/* bitmap of online cpus */
cpumask_t cpu_online_map __read_mostly;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
/* representing HT siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);

7
arch/x86/mach-voyager/voyager_smp.c
View File

@ -63,11 +63,6 @@ static int voyager_extended_cpus = 1;
/* Used for the invalidate map that's also checked in the spinlock */
static volatile unsigned long smp_invalidate_needed;
/* Bitmask of currently online CPUs - used by setup.c for
/proc/cpuinfo, visible externally but still physical */
cpumask_t cpu_online_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
/* Bitmask of CPUs present in the system - exported by i386_syms.c, used
* by scheduler but indexed physically */
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
@ -218,8 +213,6 @@ static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
/* This is for the new dynamic CPU boot code */
cpumask_t cpu_callin_map = CPU_MASK_NONE;
cpumask_t cpu_callout_map = CPU_MASK_NONE;
cpumask_t cpu_possible_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_possible_map);
/* The per processor IRQ masks (these are usually kept in sync) */
static __u16 vic_irq_mask[NR_CPUS] __cacheline_aligned;

2
include/asm-m32r/smp.h
View File

@ -63,8 +63,6 @@ extern volatile int cpu_2_physid[NR_CPUS];
#define raw_smp_processor_id() (current_thread_info()->cpu)
extern cpumask_t cpu_callout_map;
extern cpumask_t cpu_possible_map;
extern cpumask_t cpu_present_map;
static __inline__ int hard_smp_processor_id(void)
{

9
init/Kconfig
View File

@ -916,6 +916,15 @@ config KMOD
endif # MODULES
config INIT_ALL_POSSIBLE
bool
help
Back when each arch used to define their own cpu_online_map and
cpu_possible_map, some of them chose to initialize cpu_possible_map
with all 1s, and others with all 0s. When they were centralised,
it was better to provide this option than to break all the archs
and have several arch maintainers persuing me down dark alleys.
config STOP_MACHINE
bool
default y

11
kernel/cpu.c
View File

@ -24,19 +24,20 @@
cpumask_t cpu_present_map __read_mostly;
EXPORT_SYMBOL(cpu_present_map);
#ifndef CONFIG_SMP
/*
* Represents all cpu's that are currently online.
*/
cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
cpumask_t cpu_online_map __read_mostly;
EXPORT_SYMBOL(cpu_online_map);
#ifdef CONFIG_INIT_ALL_POSSIBLE
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
#else
cpumask_t cpu_possible_map __read_mostly;
#endif
EXPORT_SYMBOL(cpu_possible_map);
#else /* CONFIG_SMP */
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_map, cpu_present_map */
static DEFINE_MUTEX(cpu_add_remove_lock);