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x86: Convert a few more per-CPU items to read-mostly ones
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Both this_cpu_off and cpu_info aren't getting modified post boot, yet
are being accessed on enough code paths that grouping them with other
frequently read items seems desirable. For cpu_info this at the same
time implies removing the cache line alignment (which afaict became
pointless when it got converted to per-CPU data years ago).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/54589BD20200007800044A84@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Jan Beulich authored and Thomas Gleixner committed Nov 4, 2014
1 parent fb7183e commit 2c773dd
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Showing 4 changed files with 5 additions and 5 deletions.
2 changes: 1 addition & 1 deletion arch/x86/include/asm/percpu.h
Original file line number Diff line number Diff line change
Expand Up @@ -522,7 +522,7 @@ static inline int x86_this_cpu_variable_test_bit(int nr,
#include <asm-generic/percpu.h>

/* We can use this directly for local CPU (faster). */
DECLARE_PER_CPU(unsigned long, this_cpu_off);
DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);

#endif /* !__ASSEMBLY__ */

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4 changes: 2 additions & 2 deletions arch/x86/include/asm/processor.h
Original file line number Diff line number Diff line change
Expand Up @@ -127,7 +127,7 @@ struct cpuinfo_x86 {
/* Index into per_cpu list: */
u16 cpu_index;
u32 microcode;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));
};

#define X86_VENDOR_INTEL 0
#define X86_VENDOR_CYRIX 1
Expand All @@ -151,7 +151,7 @@ extern __u32 cpu_caps_cleared[NCAPINTS];
extern __u32 cpu_caps_set[NCAPINTS];

#ifdef CONFIG_SMP
DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
#define cpu_data(cpu) per_cpu(cpu_info, cpu)
#else
#define cpu_info boot_cpu_data
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2 changes: 1 addition & 1 deletion arch/x86/kernel/setup_percpu.c
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ EXPORT_PER_CPU_SYMBOL(cpu_number);
#define BOOT_PERCPU_OFFSET 0
#endif

DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
EXPORT_PER_CPU_SYMBOL(this_cpu_off);

unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
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2 changes: 1 addition & 1 deletion arch/x86/kernel/smpboot.c
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Expand Up @@ -99,7 +99,7 @@ EXPORT_PER_CPU_SYMBOL(cpu_core_map);
DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);

/* Per CPU bogomips and other parameters */
DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
EXPORT_PER_CPU_SYMBOL(cpu_info);

atomic_t init_deasserted;
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