Migurus,
I emailed the maintainers of the code. This is a response I got back from Alan "Maddog" Cox (with permission to post here):
Quote:
Quote:
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Perhaps you can contribute to this discussion (concerning SCO vs linux performance differences with semget):
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No but if you've got a good test case using gettimeofday() rather than time
so you get high precision time data file a bug in bugzilla.kernel.org as I
imagine Ingo Molnar and a few others might be interested.
High performance Linux code uses futex locks rather than sys5 locks but it
would still be nice to know if there really is such a big difference and why
Alan
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So here is yet another version using gettimeofday(). Don't bother posting the benchmarks here, unless they are significantly different. But prepare them for bugzilla:
Code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <time.h>
#define NSEMS 2
const static long maxseconds = 1000;
main(int argc, char *argv[])
{
struct timeval tod_start,tod_stop;
long int start,stop;
long int maxloop = 5000000;
long int i;
int sid;
key_t key;
ushort vals[NSEMS] = { 0, 0 };
if (argc > 1)
maxloop = atol(argv[1]);
i = maxloop;
key = ftok("/tmp",99);
gettimeofday(&tod_start, NULL);
while (--i) {
if ((sid = semget(key, NSEMS, IPC_CREAT | 0777)) == -1) {
perror("Can Not Get Semaphore ID");
}
if (semctl(sid, NSEMS, GETALL, vals) == -1) {
perror("Can Not Get Semaphore Values");
}
}
gettimeofday(&tod_stop,NULL);
start = 1000*1000*(tod_start.tv_sec - maxseconds) + tod_start.tv_usec;
stop = 1000*1000*(tod_stop.tv_sec - maxseconds) + tod_stop.tv_usec;
printf("%.2f semop/s (%ld/%ld)\n",
(double)maxloop/(stop-start)*1000*1000, maxloop, stop-start);
}
