bdf_prm.h

unxi下共享内存的使用

#ifndef _LINUX_BDF_PRM_H
#define _LINUX_PDF_PRM_H

/* Here is the parameter block for the bdflush process. If you add or
 * remove any of the parameters, make sure to update kernel/sysctl.c
 * and the documentation at linux/Documentation/sysctl/vm.txt.
 */

#define BDFLUSH_NR_PARAM 9

/* The dummy values in this structure are left in there for compatibility
 * with old programs that play with the /proc entries.
 */
union bdflush_param {
	struct {
		int nfract;	/* Percentage of buffer cache dirty to 
				   activate bdflush */
		int ndirty;	/* Maximum number of dirty blocks to write out per
				   wake-cycle */
		int dummy2;	/* old "nrefill" */
		int dummy3;	/* unused */
		int interval;	/* jiffies delay between kupdate flushes */
		int age_buffer;	/* Time for normal buffer to age before we flush it */
		int nfract_sync;/* Percentage of buffer cache dirty to 
				   activate bdflush synchronously */
		int nfract_stop_bdflush; /* Percetange of buffer cache dirty to stop bdflush */
		int dummy5;	/* unused */
	} b_un;
	unsigned int data[BDFLUSH_NR_PARAM];
};
extern union bdflush_param bdf_prm;
#define bdflush_interval() (bdf_prm.b_un.interval)

#endif /* _LINUX_BDF_PRM_H */