I found this. How would it work for me?
affinity.c :
/*
* Simple command-line tool to set affinity
* Robert Love, 20020311
*/
#include <stdio.h>
#include <stdlib.h>
#include <sched.h>
#include "affinity.h"
int main(int argc, char * argv[])
{
unsigned long new_mask;
unsigned long cur_mask;
unsigned int len = sizeof(new_mask);
pid_t pid;
if (argc != 3) {
printf(" usage: %s <pid> <cpu_mask>\n", argv[0]);
return -1;
}
pid = atol(argv[1]);
sscanf(argv[2], "%08lx", &new_mask);
if (sched_getaffinity(pid, len, &cur_mask) < 0) {
printf("error: could not get pid %d's affinity.\n", pid);
return -1;
}
printf(" pid %d's old affinity: %08lx\n", pid, cur_mask);
if (sched_setaffinity(pid, len, &new_mask)) {
printf("error: could not set pid %d's affinity.\n", pid);
return -1;
}
if (sched_getaffinity(pid, len, &cur_mask) < 0) {
printf("error: could not get pid %d's affinity.\n", pid);
return -1;
}
printf(" pid %d's new affinity: %08lx\n", pid, cur_mask);
return 0;
}
affinity.h :
#define _AFFINITY_H
#include <sched.h>
#include <unistd.h>
#include <linux/unistd.h>
/*
* provide the proper syscall information if our libc is not yet updated.
* It is suggested you check your kernel to make sure these are right for
* your architecture.
*/
#if defined(__i386__)
#define __NR_sched_setaffinity241
#define __NR_sched_getaffinity242
#endif
_syscall3(int, sched_setaffinity, pid_t, pid, unsigned int, len,
unsigned long *, user_mask_ptr)
_syscall3(int, sched_getaffinity, pid_t, pid, unsigned int, len,
unsigned long *, user_mask_ptr)
Compile this program:
gcc affinity.c -o affinity
Then run it like so:
affinity PID 1 (stick to CPU 0)
affinity PID 2 (stick to CPU 1)
affinity PID 3 (stick to both cpu)
EG: affinity 14932 1
If you have more processors, like 4, then affinity PID 5 would assign it to all processors (let the linux scheduler do its work) ...
I'm using this with kernel 2.5, and I believe it only works with 2.5, unless you patch your 2.4 kernel..
