/*
* libhugetlbfs - Easy use of Linux hugepages
* Copyright (C) 2008 David Gibson & Adam Litke, IBM Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _LARGEFILE64_SOURCE
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/vfs.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include "hugetlbfs.h"
#include "libhugetlbfs_privutils.h"
#include "hugetests.h"
void check_free_huge_pages(int nr_pages_needed)
{
long hpage_size = gethugepagesize();
int freepages = get_huge_page_counter(hpage_size, HUGEPAGES_FREE);
if (freepages < nr_pages_needed)
CONFIG("Must have at least %i free hugepages", nr_pages_needed);
}
int using_system_hpage_size(const char *mount)
{
struct statfs64 sb;
int err;
long meminfo_size, mount_size;
if (!mount)
FAIL("using_system_hpage_size: hugetlbfs is not mounted\n");
err = statfs64(mount, &sb);
if (err)
FAIL("statfs64: %s\n", strerror(errno));
meminfo_size = read_meminfo("Hugepagesize:");
if (meminfo_size < 0)
FAIL("using_system_hpage_size: Failed to read /proc/meminfo\n");
mount_size = sb.f_bsize / 1024; /* Compare to meminfo in kB */
if (mount_size == meminfo_size)
return 1;
else
return 0;
}
/* WARNING: This function relies on the hugetlb pool counters in a way that
* is known to be racy. Due to the expected usage of hugetlbfs test cases, the
* risk of a race is acceptible. This function should NOT be used for real
* applications.
*/
int kernel_has_private_reservations(void)
{
int fd;
long t, f, r, s;
long nt, nf, nr, ns;
long hpage_size = gethugepagesize();
void *map;
/* Read pool counters */
t = get_huge_page_counter(hpage_size, HUGEPAGES_TOTAL);
f = get_huge_page_counter(hpage_size, HUGEPAGES_FREE);
r = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
s = get_huge_page_counter(hpage_size, HUGEPAGES_SURP);
fd = hugetlbfs_unlinked_fd();
if (fd < 0) {
ERROR("kernel_has_private_reservations: hugetlbfs_unlinked_fd: "
"%s\n", strerror(errno));
return -1;
}
map = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
if (map == MAP_FAILED) {
ERROR("kernel_has_private_reservations: mmap: %s\n",
strerror(errno));
return -1;
}
/* Recheck the counters */
nt = get_huge_page_counter(hpage_size, HUGEPAGES_TOTAL);
nf = get_huge_page_counter(hpage_size, HUGEPAGES_FREE);
nr = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
ns = get_huge_page_counter(hpage_size, HUGEPAGES_SURP);
munmap(map, hpage_size);
close(fd);
/*
* There are only three valid cases:
* 1) If a surplus page was allocated to create a reservation, all
* four pool counters increment
* 2) All counters remain the same except for Hugepages_Rsvd, then
* a reservation was created using an existing pool page.
* 3) All counters remain the same, indicates that no reservation has
* been created
*/
if ((nt == t + 1) && (nf == f + 1) && (ns == s + 1) && (nr == r + 1)) {
return 1;
} else if ((nt == t) && (nf == f) && (ns == s)) {
if (nr == r + 1)
return 1;
else if (nr == r)
return 0;
} else {
ERROR("kernel_has_private_reservations: bad counter state - "
"T:%li F:%li R:%li S:%li -> T:%li F:%li R:%li S:%li\n",
t, f, r, s, nt, nf, nr, ns);
}
return -1;
}