diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-22 17:31:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-22 17:31:36 -0700 |
| commit | 0fc0531e0a2174377a86fd6953ecaa00287d8f70 (patch) | |
| tree | afe56978729300df96b002a064c9de927fadcfab /arch | |
| parent | 91b745016c12d440386c40fb76ab69c8e08cbc06 (diff) | |
| parent | 9329ba9704f6bd51a735982e0d4a3eed72c3294f (diff) | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: update comments to reflect that percpu allocations are always zero-filled
percpu: Optimize __get_cpu_var()
x86, percpu: Optimize this_cpu_ptr
percpu: clear memory allocated with the km allocator
percpu: fix build breakage on s390 and cleanup build configuration tests
percpu: use percpu allocator on UP too
percpu: reduce PCPU_MIN_UNIT_SIZE to 32k
vmalloc: pcpu_get/free_vm_areas() aren't needed on UP
Fixed up trivial conflicts in include/linux/percpu.h
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index cd28f9ad910..f899e01a8ac 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -47,6 +47,20 @@ #ifdef CONFIG_SMP #define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x #define __my_cpu_offset percpu_read(this_cpu_off) + +/* + * Compared to the generic __my_cpu_offset version, the following + * saves one instruction and avoids clobbering a temp register. + */ +#define __this_cpu_ptr(ptr) \ +({ \ + unsigned long tcp_ptr__; \ + __verify_pcpu_ptr(ptr); \ + asm volatile("add " __percpu_arg(1) ", %0" \ + : "=r" (tcp_ptr__) \ + : "m" (this_cpu_off), "0" (ptr)); \ + (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ +}) #else #define __percpu_arg(x) "%P" #x #endif |