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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-08-03 14:08:48 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-08-04 01:28:52 +0900 |
| commit | ed8d9adf357ec331603fa1049510399812cea7e5 (patch) | |
| tree | cc6eae948bf4652b9d87aee796ae78cc6287ac36 /arch/x86/include/asm/thread_info.h | |
| parent | a33a052f19a21d727847391c8c1aff3fb221c472 (diff) | |
| download | op-kernel-dev-ed8d9adf357ec331603fa1049510399812cea7e5.zip op-kernel-dev-ed8d9adf357ec331603fa1049510399812cea7e5.tar.gz | |
x86, percpu: Add 'percpu_read_stable()' interface for cacheable accesses
This is very useful for some common things like 'get_current()' and
'get_thread_info()', which can be used multiple times in a function, and
where the result is cacheable.
tj: Added the magical undocumented "P" modifier to UP __percpu_arg()
to force gcc to dereference the pointer value passed in via the
"p" input constraint. Without this, percpu_read_stable() returns
the address of the percpu variable. Also added comment explaining
the difference between percpu_read() and percpu_read_stable().
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/thread_info.h')
| -rw-r--r-- | arch/x86/include/asm/thread_info.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index fad7d40..a1bb5a11 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -213,7 +213,7 @@ DECLARE_PER_CPU(unsigned long, kernel_stack); static inline struct thread_info *current_thread_info(void) { struct thread_info *ti; - ti = (void *)(percpu_read(kernel_stack) + + ti = (void *)(percpu_read_stable(kernel_stack) + KERNEL_STACK_OFFSET - THREAD_SIZE); return ti; } |
