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Commit bfe5d834 authored by Paul Mackerras's avatar Paul Mackerras Committed by Linus Torvalds
Browse files

[PATCH] Define __raw_get_cpu_var and use it 



There are several instances of per_cpu(foo, raw_smp_processor_id()), which
is semantically equivalent to __get_cpu_var(foo) but without the warning
that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled.  For
those architectures with optimized per-cpu implementations, namely ia64,
powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower
code than __get_cpu_var(), so it would be preferable to use __get_cpu_var
on those platforms.

This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x,
raw_smp_processor_id()) on architectures that use the generic per-cpu
implementation, and turns into __get_cpu_var(x) on the architectures that
have an optimized per-cpu implementation.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6ceab8a9

include/asm-generic/percpu.h

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; 
/* var is in discarded region: offset to particular copy we want */

#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))

#define __get_cpu_var(var) per_cpu(var, smp_processor_id())

#define __raw_get_cpu_var(var) per_cpu(var, raw_smp_processor_id())



/* A macro to avoid #include hell... */

#define percpu_modcopy(pcpudst, src, size)			\
@@ -30,6 +31,7 @@ do { \ 


#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))

#define __get_cpu_var(var)			per_cpu__##var

#define __raw_get_cpu_var(var)			per_cpu__##var



#endif	/* SMP */

include/asm-ia64/percpu.h

+2 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ DECLARE_PER_CPU(unsigned long, local_per_cpu_offset); 


#define per_cpu(var, cpu)  (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]))

#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __ia64_per_cpu_var(local_per_cpu_offset)))

#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __ia64_per_cpu_var(local_per_cpu_offset)))



extern void percpu_modcopy(void *pcpudst, const void *src, unsigned long size);

extern void setup_per_cpu_areas (void);
@@ -51,6 +52,7 @@ extern void *per_cpu_init(void); 


#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))

#define __get_cpu_var(var)			per_cpu__##var

#define __raw_get_cpu_var(var)			per_cpu__##var

#define per_cpu_init()				(__phys_per_cpu_start)



#endif	/* SMP */

include/asm-powerpc/percpu.h

+2 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
/* var is in discarded region: offset to particular copy we want */

#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)))

#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))

#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))



/* A macro to avoid #include hell... */

#define percpu_modcopy(pcpudst, src, size)			\
@@ -41,6 +42,7 @@ extern void setup_per_cpu_areas(void); 


#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))

#define __get_cpu_var(var)			per_cpu__##var

#define __raw_get_cpu_var(var)			per_cpu__##var



#endif	/* SMP */

include/asm-s390/percpu.h

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; 
    __typeof__(type) per_cpu__##name



#define __get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)

#define __raw_get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)

#define per_cpu(var,cpu) __reloc_hide(var,__per_cpu_offset[cpu])



/* A macro to avoid #include hell... */
@@ -57,6 +58,7 @@ do { \ 
    __typeof__(type) per_cpu__##name



#define __get_cpu_var(var) __reloc_hide(var,0)

#define __raw_get_cpu_var(var) __reloc_hide(var,0)

#define per_cpu(var,cpu) __reloc_hide(var,0)



#endif /* SMP */

include/asm-sparc64/percpu.h

+2 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ register unsigned long __local_per_cpu_offset asm("g5"); 
/* var is in discarded region: offset to particular copy we want */

#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)))

#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __local_per_cpu_offset))

#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __local_per_cpu_offset))



/* A macro to avoid #include hell... */

#define percpu_modcopy(pcpudst, src, size)			\
@@ -37,6 +38,7 @@ do { \ 


#define per_cpu(var, cpu)			(*((void)cpu, &per_cpu__##var))

#define __get_cpu_var(var)			per_cpu__##var

#define __raw_get_cpu_var(var)			per_cpu__##var



#endif	/* SMP */