#include <u.h>#include <libc.h>#include <tos.h> typedef struct Ring Ring; struct Ring {	u32int tag[3];	void *userdata; /* for irecv */	u32int count; /* number of units; bytecount is computed using datatype*/	u32int datatype;	u32int source;	u32int itag;	u32int comm;	u32int status;	u32int xmit; /* if this was an xmit request. */	u32int done;}; voidpanic(char *str){	print("panic: %s: %r\n", str);	exits("bad");}uvlongmynsec(void){	uvlong t;	static int fd = -1;	extern int pread(int, void *, int, unsigned long long); 	if (fd < 0) {		fd = open("/dev/bintime", 0);		if (fd < 0)			panic("Can't open /dev/bintime");	} 	pread(fd, &t, sizeof(t), 0ULL);	return t;} main(int argc, char *argv[]){	int fd = open("/dev/mpi", ORDWR);	int nring = 4;	int niter = 128;	Ring *ring;	u8int *rings;	u32int cmd[3];	vlong start, end, totalbytes;	int i, j;	u32int *up;	double bw, seconds; 	if (fd < 0)		panic("no /dev/mpi"); 	if (argc > 1)		nring = strtoul(argv[1], 0, 0); 	if (argc > 2)		niter = strtoul(argv[2], 0, 0); 	/* allocate "num" ring structs */	rings = malloc(64 * nring);	/* for this test, just simulate nring 1M  reads */	for(i = 0; i < nring; i++) {		ring = (Ring *)&rings[i*64];		ring->userdata = malloc(1048576);		ring->count = 1048576/4;		ring->datatype = 4;//		print("ring %p userdata %p count %d\n", ring, ring->userdata, ring->count);	}	print("Sleeping a billion counts to let everyone catch up\n");	{ int i; for(i = 0; i < 1000000000; i++);}	print("Proceeding\n");	cmd[0] = 'r';	cmd[1] = (u32int) rings;	cmd[2] = (u32int) nring;	print("Command %c %#lx %d\n", cmd[0], cmd[1], cmd[2]);	write(fd, cmd, sizeof(cmd));	cmd[0] = 'g';	start = mynsec();	for (i = 0; i < niter; i++){		write(fd, cmd, sizeof(cmd[0]));		for(j = 0; j < nring; j++) {			ring = (Ring *)&rings[j*64];			ring->done = 0;		}	}	end = mynsec();	print("Start %ullx end %ullx Total nsecs %ullx\n", start, end, end - start);	print("total bytes transferred: %dMB\n", nring * niter);	totalbytes = nring * niter * 1048576;/*	seconds = (end - start);	seconds /= 1e9;	bw = totalbytes;	bw /= seconds;*/	print("nring %d niter %d %ulld bytes in %ulld nanoseconds\n", nring, niter, totalbytes, end-start);//	print("Bandwidth: %g\n", bw);} /* qc testring.c&& ql -o testring testring.q&&date&&ls -l testring/usr/rminnich//bin/386/scp testring surveyor.alcf.anl.gov:rompi*/