prior to 2.6.21 i could "numactl --interleave=all" and use SHM_HUGETLB and 
the interleave policy would be respected.  as of 2.6.21 it doesn't seem to 
respect the policy on SHM_HUGETLB request.

see test program below.

output from pre-2.6.21:

2ab196200000 interleave=0-3 file=/2\040(deleted) huge dirty=32 N0=8 N1=8 N2=8 
N3=8
2ab19a200000 default file=/SYSV00000000\040(deleted) dirty=16384 active=0 
N0=4096 N1=4096 N2=4096 N3=4096

output from 2.6.21:

2b49b1c00000 default file=/10\040(deleted) huge dirty=32 N3=32
2b49b5c00000 default file=/SYSV00000000\040(deleted) dirty=16384 active=0 
N0=4096 N1=4096 N2=4096 N3=4096

was this an intentional behaviour change?  it seems to be only affecting 
SHM_HUGETLB allocations.  (i haven't tested hugetlbfs yet.)

run with "numactl --interleave=all ./shmtest"

-dean

/* shmtest.c */

#include <sys/mman.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>


static void *alloc_arena_shm(size_t arena_size, unsigned flags)
{
        FILE *fh;
        char buf[512];
        size_t huge_page_size;
        char *p;
        int shmid;
        void *arena;

        // find Hugepagesize in /proc/meminfo
        if ((fh = fopen("/proc/meminfo", "r")) == NULL) {
                perror("open(/proc/meminfo)");
                exit(1);
        }
        for (;;) {
                if (fgets(buf, sizeof(buf)-1, fh) == NULL) {
                        fprintf(stderr, "didn't find Hugepagesize in 
/proc/meminfo");
                        exit(1);
                }
                buf[sizeof(buf)-1] = '\0';
                if (strncmp(buf, "Hugepagesize:", 13) == 0) break;
        }
        p = strchr(buf, ':') + 1;
        huge_page_size = strtoul(p, 0, 0) * 1024;
        fclose(fh);

        // round the size up to multiple of huge_page_size
        arena_size = (arena_size + huge_page_size - 1) & ~(huge_page_size - 1);

        shmid = shmget(IPC_PRIVATE, arena_size, IPC_CREAT|IPC_EXCL|flags|0600);
        if (shmid == -1) {
                perror("shmget");
                exit(1);
        }

        arena = shmat(shmid, NULL, 0);
        if (arena == (void *)-1) {
                perror("shmat");
                exit(1);
        }

        if (shmctl(shmid, IPC_RMID, 0) == -1) {
                perror("shmctl warning");
        }

        return arena;
}

int main(int argc, char **argv)
{
        char buf[1024];
        const size_t sz = 64*1024*1024;
        void *arena = alloc_arena_shm(sz, SHM_HUGETLB);
        memset(arena, 0, sz);
        snprintf(buf, sizeof(buf), "grep ^%llx /proc/%d/numa_maps", (unsigned 
long long)arena, (int)getpid());
        system(buf);

        arena = alloc_arena_shm(sz, 0);
        memset(arena, 0, sz);
        snprintf(buf, sizeof(buf), "grep ^%llx /proc/%d/numa_maps", (unsigned 
long long)arena, (int)getpid());
        system(buf);

        return 0;
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to