diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2012-11-27 23:28:57 -0200 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-11-27 23:29:11 -0200 |
| commit | 51c19b4f5927f5a646e93d69f73c7e89ea14e737 (patch) | |
| tree | a48486f72dc433fd516684d4441022650429d333 /arch/x86/vdso/vgetcpu.c | |
| parent | 3dc4f7cfb7441e5e0fed3a02fc81cdaabd28300a (diff) | |
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 <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/vdso/vgetcpu.c')
| -rw-r--r-- | arch/x86/vdso/vgetcpu.c | 11 |
1 files changed, 3 insertions, 8 deletions
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; |