From: Ingo Molnar Date: Tue, 10 Mar 2009 18:02:30 +0000 (+0100) Subject: x86, sched_clock(): mark variables read-mostly X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f24ade3a3332811a512ed3b6c6aa69486719b1d8;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git 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 --- diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 599e58168631..9c8b71531ca8 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -17,20 +17,21 @@ #include #include -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; /*