diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-03-10 19:02:30 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-10 19:02:30 +0100 |
| commit | f24ade3a3332811a512ed3b6c6aa69486719b1d8 (patch) | |
| tree | 639fd20053f3c3738ee8ff7893753741e8c684c0 | |
| parent | 8325d9c09dedf45476f4d6261d1b6a72e4a7453f (diff) | |
x86, sched_clock(): mark variables read-mostly
Impact: micro-optimization
There's a number of variables in the sched_clock() path that are
in .data/.bss - but not marked __read_mostly. This creates the
danger of accidental false cacheline sharing with some other,
write-often variable.
So mark them __read_mostly.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/tsc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 599e5816863..9c8b71531ca 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -17,20 +17,21 @@ #include <asm/delay.h> #include <asm/hypervisor.h> -unsigned int cpu_khz; /* TSC clocks / usec, not used here */ +unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); -unsigned int tsc_khz; + +unsigned int __read_mostly tsc_khz; EXPORT_SYMBOL(tsc_khz); /* * TSC can be unstable due to cpufreq or due to unsynced TSCs */ -static int tsc_unstable; +static int __read_mostly tsc_unstable; /* native_sched_clock() is called before tsc_init(), so we must start with the TSC soft disabled to prevent erroneous rdtsc usage on !cpu_has_tsc processors */ -static int tsc_disabled = -1; +static int __read_mostly tsc_disabled = -1; static int tsc_clocksource_reliable; /* |