include/linux/kernel.h

#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H

/*
 * 'kernel.h' contains some often-used function prototypes etc
 */
#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))



#define SI_LOAD_SHIFT	16
struct sysinfo {
	long uptime;			/* Seconds since boot */
	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
	unsigned long totalram;		/* Total usable main memory size */
	unsigned long freeram;		/* Available memory size */
	unsigned long sharedram;	/* Amount of shared memory */
	unsigned long bufferram;	/* Memory used by buffers */
	unsigned long totalswap;	/* Total swap space size */
	unsigned long freeswap;		/* swap space still available */
	unsigned short procs;		/* Number of current processes */
	unsigned short pad;		/* explicit padding for m68k */
	unsigned long totalhigh;	/* Total high memory size */
	unsigned long freehigh;		/* Available high memory size */
	unsigned int mem_unit;		/* Memory unit size in bytes */
	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
};

/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))

/* Force a compilation error if condition is constant and true */
#define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))

/* Force a compilation error if a constant expression is not a power of 2 */
#define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))

/* Force a compilation error if condition is true, but also produce a
   result (of value 0 and type size_t), so the expression can be used
   e.g. in a structure initializer (or where-ever else comma expressions
   aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)

/* This helps us to avoid #ifdef CONFIG_NUMA */
#ifdef CONFIG_NUMA
#define NUMA_BUILD 1
#else
#define NUMA_BUILD 0
#endif

/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
#endif

#endif