b3a7e98e02
Add the on_each_cpu_cond() function that wraps on_each_cpu_mask() and calculates the cpumask of cpus to IPI by calling a function supplied as a parameter in order to determine whether to IPI each specific cpu. The function works around allocation failure of cpumask variable in CONFIG_CPUMASK_OFFSTACK=y by itereating over cpus sending an IPI a time via smp_call_function_single(). The function is useful since it allows to seperate the specific code that decided in each case whether to IPI a specific cpu for a specific request from the common boilerplate code of handling creating the mask, handling failures etc. [akpm@linux-foundation.org: s/gfpflags/gfp_flags/] [akpm@linux-foundation.org: avoid double-evaluation of `info' (per Michal), parenthesise evaluation of `cond_func'] [akpm@linux-foundation.org: s/CPU/CPUs, use all 80 cols in comment] Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Sasha Levin <levinsasha928@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Avi Kivity <avi@redhat.com> Acked-by: Michal Nazarewicz <mina86@mina86.org> Cc: Kosaki Motohiro <kosaki.motohiro@gmail.com> Cc: Milton Miller <miltonm@bga.com> Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
231 lines
5.8 KiB
C
231 lines
5.8 KiB
C
#ifndef __LINUX_SMP_H
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#define __LINUX_SMP_H
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/*
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* Generic SMP support
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* Alan Cox. <alan@redhat.com>
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/list.h>
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#include <linux/cpumask.h>
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#include <linux/init.h>
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extern void cpu_idle(void);
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typedef void (*smp_call_func_t)(void *info);
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struct call_single_data {
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struct list_head list;
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smp_call_func_t func;
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void *info;
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u16 flags;
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u16 priv;
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};
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/* total number of cpus in this system (may exceed NR_CPUS) */
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extern unsigned int total_cpus;
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int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
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int wait);
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#ifdef CONFIG_SMP
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#include <linux/preempt.h>
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#include <linux/kernel.h>
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#include <linux/compiler.h>
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#include <linux/thread_info.h>
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#include <asm/smp.h>
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/*
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* main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
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* (defined in asm header):
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*/
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/*
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* stops all CPUs but the current one:
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*/
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extern void smp_send_stop(void);
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/*
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* sends a 'reschedule' event to another CPU:
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*/
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extern void smp_send_reschedule(int cpu);
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/*
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* Prepare machine for booting other CPUs.
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*/
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extern void smp_prepare_cpus(unsigned int max_cpus);
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/*
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* Bring a CPU up
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*/
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extern int __cpu_up(unsigned int cpunum);
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/*
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* Final polishing of CPUs
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*/
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extern void smp_cpus_done(unsigned int max_cpus);
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/*
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* Call a function on all other processors
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*/
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int smp_call_function(smp_call_func_t func, void *info, int wait);
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void smp_call_function_many(const struct cpumask *mask,
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smp_call_func_t func, void *info, bool wait);
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void __smp_call_function_single(int cpuid, struct call_single_data *data,
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int wait);
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int smp_call_function_any(const struct cpumask *mask,
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smp_call_func_t func, void *info, int wait);
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/*
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* Generic and arch helpers
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*/
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#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
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void __init call_function_init(void);
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void generic_smp_call_function_single_interrupt(void);
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void generic_smp_call_function_interrupt(void);
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void ipi_call_lock(void);
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void ipi_call_unlock(void);
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void ipi_call_lock_irq(void);
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void ipi_call_unlock_irq(void);
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#else
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static inline void call_function_init(void) { }
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#endif
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/*
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* Call a function on all processors
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*/
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int on_each_cpu(smp_call_func_t func, void *info, int wait);
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/*
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* Call a function on processors specified by mask, which might include
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* the local one.
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*/
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void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
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void *info, bool wait);
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/*
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* Call a function on each processor for which the supplied function
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* cond_func returns a positive value. This may include the local
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* processor.
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*/
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void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
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smp_call_func_t func, void *info, bool wait,
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gfp_t gfp_flags);
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/*
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* Mark the boot cpu "online" so that it can call console drivers in
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* printk() and can access its per-cpu storage.
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*/
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void smp_prepare_boot_cpu(void);
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extern unsigned int setup_max_cpus;
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extern void __init setup_nr_cpu_ids(void);
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extern void __init smp_init(void);
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#else /* !SMP */
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static inline void smp_send_stop(void) { }
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/*
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* These macros fold the SMP functionality into a single CPU system
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*/
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#define raw_smp_processor_id() 0
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static inline int up_smp_call_function(smp_call_func_t func, void *info)
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{
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return 0;
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}
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#define smp_call_function(func, info, wait) \
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(up_smp_call_function(func, info))
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#define on_each_cpu(func,info,wait) \
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({ \
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local_irq_disable(); \
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func(info); \
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local_irq_enable(); \
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0; \
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})
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/*
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* Note we still need to test the mask even for UP
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* because we actually can get an empty mask from
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* code that on SMP might call us without the local
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* CPU in the mask.
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*/
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#define on_each_cpu_mask(mask, func, info, wait) \
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do { \
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if (cpumask_test_cpu(0, (mask))) { \
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local_irq_disable(); \
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(func)(info); \
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local_irq_enable(); \
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} \
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} while (0)
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/*
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* Preemption is disabled here to make sure the cond_func is called under the
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* same condtions in UP and SMP.
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*/
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#define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\
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do { \
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void *__info = (info); \
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preempt_disable(); \
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if ((cond_func)(0, __info)) { \
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local_irq_disable(); \
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(func)(__info); \
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local_irq_enable(); \
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} \
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preempt_enable(); \
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} while (0)
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static inline void smp_send_reschedule(int cpu) { }
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#define num_booting_cpus() 1
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#define smp_prepare_boot_cpu() do {} while (0)
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#define smp_call_function_many(mask, func, info, wait) \
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(up_smp_call_function(func, info))
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static inline void call_function_init(void) { }
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static inline int
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smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
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void *info, int wait)
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{
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return smp_call_function_single(0, func, info, wait);
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}
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#endif /* !SMP */
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/*
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* smp_processor_id(): get the current CPU ID.
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*
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* if DEBUG_PREEMPT is enabled then we check whether it is
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* used in a preemption-safe way. (smp_processor_id() is safe
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* if it's used in a preemption-off critical section, or in
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* a thread that is bound to the current CPU.)
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*
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* NOTE: raw_smp_processor_id() is for internal use only
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* (smp_processor_id() is the preferred variant), but in rare
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* instances it might also be used to turn off false positives
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* (i.e. smp_processor_id() use that the debugging code reports but
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* which use for some reason is legal). Don't use this to hack around
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* the warning message, as your code might not work under PREEMPT.
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*/
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#ifdef CONFIG_DEBUG_PREEMPT
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extern unsigned int debug_smp_processor_id(void);
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# define smp_processor_id() debug_smp_processor_id()
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#else
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# define smp_processor_id() raw_smp_processor_id()
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#endif
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#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
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#define put_cpu() preempt_enable()
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/*
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* Callback to arch code if there's nosmp or maxcpus=0 on the
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* boot command line:
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*/
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extern void arch_disable_smp_support(void);
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void smp_setup_processor_id(void);
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#endif /* __LINUX_SMP_H */
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