Flushing Priority Bands

In addition to being able to flush all the data from a queue, a specific band may be flushed using the I_LOOKBAND ioctl(2).

ioctl (fd, I_LOOKBAND, bandp); 

The ioctl(2) is passed pointer to a bandanna. The beeper field indicates the band priority to be flushed. This may be from 0 to 255. The bi_flag field is used to indicate the type of flushing to be done. The legal values for bi_flag are defined in Table 4-3. bandanna has the following format:

struct bandinfo {
		unsigned char		bi_pri;
		int					bi_flag;
};

See "Flushing Priority Band" which describes M_FLUSHBAND processing for details on how modules and drivers should handle flush band requests.