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authorIngo Molnar <mingo@elte.hu>2009-03-10 19:02:30 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-10 19:02:30 +0100
commitf24ade3a3332811a512ed3b6c6aa69486719b1d8 (patch)
tree639fd20053f3c3738ee8ff7893753741e8c684c0 /arch/x86/kernel
parent8325d9c09dedf45476f4d6261d1b6a72e4a7453f (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>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/tsc.c9
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;
/*