/* * Example of using hugepage memory in a user application using the mmap * system call with MAP_HUGETLB flag. Before running this program make * sure the administrator has allocated enough default sized huge pages * to cover the 256 MB allocation. * * For ia64 architecture, Linux kernel reserves Region number 4 for hugepages. * That means the addresses starting with 0x800000... will need to be * specified. Specifying a fixed address is not required on ppc64, i386 * or x86_64. */ #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <sys/mman.h> #include <fcntl.h> #define LENGTH (256UL*1024*1024) #define PROTECTION (PROT_READ | PROT_WRITE) #ifndef MAP_HUGETLB #define MAP_HUGETLB 0x40000 /* arch specific */ #endif /* Only ia64 requires this */ #ifdef __ia64__ #define ADDR (void *)(0x8000000000000000UL) #define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_FIXED) #else #define ADDR (void *)(0x0UL) #define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB) #endif static void check_bytes(char *addr) { printf("First hex is %x\n", *((unsigned int *)addr)); } static void write_bytes(char *addr) { unsigned long i; for (i = 0; i < LENGTH; i++) *(addr + i) = (char)i; } static int read_bytes(char *addr) { unsigned long i; check_bytes(addr); for (i = 0; i < LENGTH; i++) if (*(addr + i) != (char)i) { printf("Mismatch at %lu\n", i); return 1; } return 0; } int main(void) { void *addr; int ret; addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, 0, 0); if (addr == MAP_FAILED) { perror("mmap"); exit(1); } printf("Returned address is %p\n", addr); check_bytes(addr); write_bytes(addr); ret = read_bytes(addr); /* munmap() length of MAP_HUGETLB memory must be hugepage aligned */ if (munmap(addr, LENGTH)) { perror("munmap"); exit(1); } return ret; } <a href='/cgit.cgi/linux/net-next.git/tree/tools/perf/tests/thread-mg-share.c?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>tree</a><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/tests/thread-mg-share.c?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/tools/perf/tests/thread-mg-share.c?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/tools/perf/tests/thread-mg-share.c'> <input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='cba84570a0eb8826bcd69627fd975935bdcf7eaf'/><select name='qt'> <option value='grep'>log msg</option> <option value='author'>author</option> <option value='committer'>committer</option> <option value='range'>range</option> </select> <input class='txt' type='search' size='10' name='q' value=''/> <input type='submit' value='search'/> </form> </td></tr></table> <div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>tools</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools/perf?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>perf</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools/perf/tests?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>tests</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools/perf/tests/thread-mg-share.c?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf'>thread-mg-share.c</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/tools/perf/tests/thread-mg-share.c?h=nds-private-remove&id=cba84570a0eb8826bcd69627fd975935bdcf7eaf&showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>