#ifndef _ASM_X86_MMU_H
#define _ASM_X86_MMU_H

#include <linux/spinlock.h>
#include <linux/mutex.h>

/*
 * The x86 doesn't have a mmu context, but
 * we put the segment information here.
 */
typedef struct {
	void *ldt;
	int size;
	struct mutex lock;
	void *vdso;

#ifdef CONFIG_X86_64
	/* True if mm supports a task running in 32 bit compatibility mode. */
	unsigned short ia32_compat;
#endif

} mm_context_t;

#ifdef CONFIG_SMP
void leave_mm(int cpu);
#else
static inline void leave_mm(int cpu)
{
}
#endif

#endif /* _ASM_X86_MMU_H */

#ifndef _ASM_X86_MMU_H
#define _ASM_X86_MMU_H

#include <linux/spinlock.h>
#include <linux/mutex.h>

/*
 * The x86 doesn't have a mmu context, but
 * we put the segment information here.
 */
typedef struct {
	void *ldt;
	int size;

#ifdef CONFIG_X86_64
	/* True if mm supports a task running in 32 bit compatibility mode. */
	unsigned short ia32_compat;
#endif

	struct mutex lock;
	void *vdso;
} mm_context_t;

#ifdef CONFIG_SMP
void leave_mm(int cpu);
#else
static inline void leave_mm(int cpu)
{
}
#endif

#endif /* _ASM_X86_MMU_H */

Reorder mm_context_t to remove x86_64 alignment padding and thus shrink mm_struct
x86: Reorder mm_context_t to remove x86_64 alignment padding and thus shrink mm_struct

Reorder mm_context_t to remove alignment padding on 64 bit
builds shrinking its size from 64 to 56 bytes.

This allows mm_struct to shrink from 840 to 832 bytes, so using
one fewer cache lines, and getting more objects per slab when
using slub.

slabinfo mm_struct reports
before :-

    Sizes (bytes)     Slabs
    -----------------------------------
    Object :     840  Total  :       7
    SlabObj:     896  Full   :       1
    SlabSiz:   16384  Partial:       4
    Loss   :      56  CpuSlab:       2
    Align  :      64  Objects:      18

after :-

    Sizes (bytes)     Slabs
    ----------------------------------
    Object :     832  Total  :       7
    SlabObj:     832  Full   :       1
    SlabSiz:   16384  Partial:       4
    Loss   :       0  CpuSlab:       2
    Align  :      64  Objects:      19

Signed-off-by: Richard Kennedy <320bca71fc381a4a025636043ca86e734e31cf8b@rsk.demon.co.uk>
Cc: 3d378e0efa9324a1bec5e3bea0c8445f2cc384d0@start.ca
Cc: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
Cc: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Cc: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@kernel.org>
Link: f96f24409da09dd8fdaa8f3abbce8686f58ad694@castor.rsk
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>
