From 51c19b4f5927f5a646e93d69f73c7e89ea14e737 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Tue, 27 Nov 2012 23:28:57 -0200 Subject: x86: vdso: pvclock gettime support Improve performance of time system calls when using Linux pvclock, by reading time info from fixmap visible copy of pvclock data. Originally from Jeremy Fitzhardinge. Signed-off-by: Marcelo Tosatti --- arch/x86/vdso/vgetcpu.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'arch/x86/vdso/vgetcpu.c') diff --git a/arch/x86/vdso/vgetcpu.c b/arch/x86/vdso/vgetcpu.c index 5463ad558573..2f94b039e55b 100644 --- a/arch/x86/vdso/vgetcpu.c +++ b/arch/x86/vdso/vgetcpu.c @@ -17,15 +17,10 @@ __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) { unsigned int p; - if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { - /* Load per CPU data from RDTSCP */ - native_read_tscp(&p); - } else { - /* Load per CPU data from GDT */ - asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); - } + p = __getcpu(); + if (cpu) - *cpu = p & 0xfff; + *cpu = p & VGETCPU_CPU_MASK; if (node) *node = p >> 12; return 0; -- cgit v1.2.2