diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2017-02-14 11:11:04 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-03-11 14:45:18 +0300 |
| commit | 5a920155e388ec22a22e0532fb695b9215c9b34d (patch) | |
| tree | e92bef00945f4180419a0ea81bc667bb3f542054 /arch/x86/include/asm | |
| parent | b9894a2f5bd18b1691cb6872c9afe32b148d0132 (diff) | |
| download | linux-5a920155e388ec22a22e0532fb695b9215c9b34d.tar.xz | |
x86/process: Optimize TIF_NOTSC switch
Provide and use a toggle helper instead of doing it with a branch.
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3008 8577 16 11601 2d51 Before
2976 8577 16 11569 2d31 After
i386: arch/x86/kernel/process.o
text data bss dec hex
2925 8673 8 11606 2d56 Before
2893 8673 8 11574 2d36 After
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-4-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/tlbflush.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 6fa85944af83..ff4923a19f79 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -110,6 +110,16 @@ static inline void cr4_clear_bits(unsigned long mask) } } +static inline void cr4_toggle_bits(unsigned long mask) +{ + unsigned long cr4; + + cr4 = this_cpu_read(cpu_tlbstate.cr4); + cr4 ^= mask; + this_cpu_write(cpu_tlbstate.cr4, cr4); + __write_cr4(cr4); +} + /* Read the CR4 shadow. */ static inline unsigned long cr4_read_shadow(void) { |