lmbench－一个benchmark for linux

* Suite of simple, portable benchmarks * Compares different systems performance * Results available for most major vendors (SUN, HP, IBM, DEC, SGI, PCs including 200 Mhz P6's) * Free software, covered by the GNU General Public License. * Bandwidth benchmarks o Cached file read o Memory copy (bcopy) o Memory read o Memory write o Pipe o TCP * Latency benchmarks o Context switching. o Networking: connection establishment, pipe, TCP, UDP, and RPC hot potato o File system creates and deletes. o Process creation. o Signal handling o System call overhead o Memory read latency * Miscellanious o Processor clock rate calculation

volatile int i;

main（）
{

	nice（10）;
	for （;;） getppid（）;
	//for （;;） i++;
	exit（i）;
}