Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: optimize sched_clock() a bit
  sched: improve sched_clock() performance

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 46be2fa7ac266c513bfd3221b7f0d861e748238d..c2a812ebde890e590794ea1e2d8a39d5cec49e9f 100644 (file)
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -108,9 +108,7 @@ static __always_inline unsigned long long __native_read_tsc(void)
 {
        DECLARE_ARGS(val, low, high);
 
-       rdtsc_barrier();
        asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
-       rdtsc_barrier();
 
        return EAX_EDX_VAL(val, low, high);
 }

diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index 38ae163cc91b00bf029d5ed5e29cd8ba96bd461b..9cd83a8e40d59a3dae2978e23887d81311370ae3 100644 (file)
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -34,6 +34,8 @@ static inline cycles_t get_cycles(void)
 
 static __always_inline cycles_t vget_cycles(void)
 {
+       cycles_t cycles;
+
        /*
         * We only do VDSOs on TSC capable CPUs, so this shouldnt
         * access boot_cpu_data (which is not VDSO-safe):
@@ -42,7 +44,11 @@ static __always_inline cycles_t vget_cycles(void)
        if (!cpu_has_tsc)
                return 0;
 #endif
-       return (cycles_t)__native_read_tsc();
+       rdtsc_barrier();
+       cycles = (cycles_t)__native_read_tsc();
+       rdtsc_barrier();
+
+       return cycles;
 }
 
 extern void tsc_init(void);

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2ef80e30192571a633f8fb3fb858c20207b9d4d7..424093b157d363dcad0bb58b8ed08636a9e0b61e 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -55,7 +55,7 @@ u64 native_sched_clock(void)
        rdtscll(this_offset);
 
        /* return the value in ns */
-       return cycles_2_ns(this_offset);
+       return __cycles_2_ns(this_offset);
 }
 
 /* We need to define a real function for sched_clock, to override the