The patch titled
Subject: selftests: vm: add tests for lock on fault
has been added to the -mm tree. Its filename is
selftests-vm-add-tests-for-lock-on-fault.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/selftests-vm-add-tests-for-lock-on-fault.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/selftests-vm-add-tests-for-lock-on-fault.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Eric B Munson <emunson@xxxxxxxxxx>
Subject: selftests: vm: add tests for lock on fault
Test the mmap() flag, and the mlockall() flag. These tests ensure that
pages are not faulted in until they are accessed, that the pages are
unevictable once faulted in, and that VMA splitting and merging works with
the new VM flag. The second test ensures that mlock limits are respected.
Note that the limit test needs to be run a normal user.
Signed-off-by: Eric B Munson <emunson@xxxxxxxxxx>
Cc: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/Makefile | 2
tools/testing/selftests/vm/lock-on-fault.c | 342 ++++++++++++++++++
tools/testing/selftests/vm/on-fault-limit.c | 47 ++
tools/testing/selftests/vm/run_vmtests | 22 +
4 files changed, 413 insertions(+)
diff -puN tools/testing/selftests/vm/Makefile~selftests-vm-add-tests-for-lock-on-fault tools/testing/selftests/vm/Makefile
--- a/tools/testing/selftests/vm/Makefile~selftests-vm-add-tests-for-lock-on-fault
+++ a/tools/testing/selftests/vm/Makefile
@@ -5,7 +5,9 @@ BINARIES = compaction_test
BINARIES += hugepage-mmap
BINARIES += hugepage-shm
BINARIES += hugetlbfstest
+BINARIES += lock-on-fault
BINARIES += map_hugetlb
+BINARIES += on-fault-limit
BINARIES += thuge-gen
BINARIES += transhuge-stress
diff -puN /dev/null tools/testing/selftests/vm/lock-on-fault.c
--- /dev/null
+++ a/tools/testing/selftests/vm/lock-on-fault.c
@@ -0,0 +1,342 @@
+#include <sys/mman.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+struct vm_boundaries {
+ unsigned long start;
+ unsigned long end;
+};
+
+static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
+{
+ FILE *file;
+ int ret = 1;
+ char line[1024] = {0};
+ char *end_addr;
+ char *stop;
+ unsigned long start;
+ unsigned long end;
+
+ if (!area)
+ return ret;
+
+ file = fopen("/proc/self/maps", "r");
+ if (!file) {
+ perror("fopen");
+ return ret;
+ }
+
+ memset(area, 0, sizeof(struct vm_boundaries));
+
+ while(fgets(line, 1024, file)) {
+ end_addr = strchr(line, '-');
+ if (!end_addr) {
+ printf("cannot parse /proc/self/maps\n");
+ goto out;
+ }
+ *end_addr = '\0';
+ end_addr++;
+ stop = strchr(end_addr, ' ');
+ if (!stop) {
+ printf("cannot parse /proc/self/maps\n");
+ goto out;
+ }
+ stop = '\0';
+
+ sscanf(line, "%lx", &start);
+ sscanf(end_addr, "%lx", &end);
+
+ if (start <= addr && end > addr) {
+ area->start = start;
+ area->end = end;
+ ret = 0;
+ goto out;
+ }
+ }
+out:
+ fclose(file);
+ return ret;
+}
+
+static unsigned long get_pageflags(unsigned long addr)
+{
+ FILE *file;
+ unsigned long pfn;
+ unsigned long offset;
+
+ file = fopen("/proc/self/pagemap", "r");
+ if (!file) {
+ perror("fopen");
+ _exit(1);
+ }
+
+ offset = addr / getpagesize() * sizeof(unsigned long);
+ if (fseek(file, offset, SEEK_SET)) {
+ perror("fseek");
+ _exit(1);
+ }
+
+ if (fread(&pfn, sizeof(unsigned long), 1, file) != 1) {
+ perror("fread");
+ _exit(1);
+ }
+
+ fclose(file);
+ return pfn;
+}
+
+static unsigned long get_kpageflags(unsigned long pfn)
+{
+ unsigned long flags;
+ FILE *file;
+
+ file = fopen("/proc/kpageflags", "r");
+ if (!file) {
+ perror("fopen");
+ _exit(1);
+ }
+
+ if (fseek(file, pfn * sizeof(unsigned long), SEEK_SET)) {
+ perror("fseek");
+ _exit(1);
+ }
+
+ if (fread(&flags, sizeof(unsigned long), 1, file) != 1) {
+ perror("fread");
+ _exit(1);
+ }
+
+ fclose(file);
+ return flags;
+}
+
+#define PRESENT_BIT 0x8000000000000000
+#define PFN_MASK 0x007FFFFFFFFFFFFF
+#define UNEVICTABLE_BIT (1UL << 18)
+
+static int test_mmap(int flags)
+{
+ unsigned long page1_flags;
+ unsigned long page2_flags;
+ void *map;
+ unsigned long page_size = getpagesize();
+
+ map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, flags, 0, 0);
+ if (map == MAP_FAILED) {
+ perror("mmap()");
+ return 1;
+ }
+
+ /* Write something into the first page to ensure it is present */
+ *(char *)map = 1;
+
+ page1_flags = get_pageflags((unsigned long)map);
+ page2_flags = get_pageflags((unsigned long)map + page_size);
+
+ /* page2_flags should not be present */
+ if (page2_flags & PRESENT_BIT) {
+ printf("page map says 0x%lx\n", page2_flags);
+ printf("present is 0x%lx\n", PRESENT_BIT);
+ return 1;
+ }
+
+ /* page1_flags should be present */
+ if (page1_flags & PRESENT_BIT == 0) {
+ printf("page map says 0x%lx\n", page1_flags);
+ printf("present is 0x%lx\n", PRESENT_BIT);
+ return 1;
+ }
+
+ page1_flags = get_kpageflags(page1_flags & PFN_MASK);
+
+ /* page1_flags now contains the entry from kpageflags for the first
+ * page, the unevictable bit should be set */
+ if (page1_flags & UNEVICTABLE_BIT == 0) {
+ printf("kpageflags says 0x%lx\n", page1_flags);
+ printf("unevictable is 0x%lx\n", UNEVICTABLE_BIT);
+ return 1;
+ }
+
+ munmap(map, 2 * page_size);
+ return 0;
+}
+
+static int test_munlock(int flags)
+{
+ int ret = 1;
+ void *map;
+ unsigned long page1_flags;
+ unsigned long page2_flags;
+ unsigned long page3_flags;
+ unsigned long page_size = getpagesize();
+
+ map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE, flags, 0, 0);
+ if (map == MAP_FAILED) {
+ perror("mmap()");
+ return ret;
+ }
+
+ if (munlock(map + page_size, page_size)) {
+ perror("munlock()");
+ goto out;
+ }
+
+ page1_flags = get_pageflags((unsigned long)map);
+ page2_flags = get_pageflags((unsigned long)map + page_size);
+ page3_flags = get_pageflags((unsigned long)map + page_size * 2);
+
+ /* No pages should be present */
+ if ((page1_flags & PRESENT_BIT) || (page2_flags & PRESENT_BIT) ||
+ (page3_flags & PRESENT_BIT)) {
+ printf("Page was made present by munlock()\n");
+ goto out;
+ }
+
+ /* Write something to each page so that they are faulted in */
+ *(char*)map = 1;
+ *(char*)(map + page_size) = 1;
+ *(char*)(map + page_size * 2) = 1;
+
+ page1_flags = get_pageflags((unsigned long)map);
+ page2_flags = get_pageflags((unsigned long)map + page_size);
+ page3_flags = get_pageflags((unsigned long)map + page_size * 2);
+
+ page1_flags = get_kpageflags(page1_flags & PFN_MASK);
+ page2_flags = get_kpageflags(page2_flags & PFN_MASK);
+ page3_flags = get_kpageflags(page3_flags & PFN_MASK);
+
+ /* Pages 1 and 3 should be unevictable */
+ if (!(page1_flags & UNEVICTABLE_BIT)) {
+ printf("Missing unevictable bit on lock on fault page1\n");
+ goto out;
+ }
+ if (!(page3_flags & UNEVICTABLE_BIT)) {
+ printf("Missing unevictable bit on lock on fault page3\n");
+ goto out;
+ }
+
+ /* Page 2 should not be unevictable */
+ if (page2_flags & UNEVICTABLE_BIT) {
+ printf("Unlocked page is still marked unevictable\n");
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+ munmap(map, 3 * page_size);
+ return ret;
+}
+
+static int test_vma_management(int flags)
+{
+ int ret = 1;
+ void *map;
+ unsigned long page_size = getpagesize();
+ struct vm_boundaries page1;
+ struct vm_boundaries page2;
+ struct vm_boundaries page3;
+
+ map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE, flags, 0, 0);
+ if (map == MAP_FAILED) {
+ perror("mmap()");
+ return ret;
+ }
+
+ if (get_vm_area((unsigned long)map, &page1) ||
+ get_vm_area((unsigned long)map + page_size, &page2) ||
+ get_vm_area((unsigned long)map + page_size * 2, &page3)) {
+ printf("couldn't find mapping in /proc/self/maps\n");
+ goto out;
+ }
+
+ /*
+ * Before we unlock a portion, we need to that all three pages are in
+ * the same VMA. If they are not we abort this test (Note that this is
+ * not a failure)
+ */
+ if (page1.start != page2.start || page2.start != page3.start) {
+ printf("VMAs are not merged to start, aborting test\n");
+ ret = 0;
+ goto out;
+ }
+
+ if (munlock(map + page_size, page_size)) {
+ perror("munlock()");
+ goto out;
+ }
+
+ if (get_vm_area((unsigned long)map, &page1) ||
+ get_vm_area((unsigned long)map + page_size, &page2) ||
+ get_vm_area((unsigned long)map + page_size * 2, &page3)) {
+ printf("couldn't find mapping in /proc/self/maps\n");
+ goto out;
+ }
+
+ /* All three VMAs should be different */
+ if (page1.start == page2.start || page2.start == page3.start) {
+ printf("failed to split VMA for munlock\n");
+ goto out;
+ }
+
+ /* Now unlock the first and third page and check the VMAs again */
+ if (munlock(map, page_size * 3)) {
+ perror("munlock()");
+ goto out;
+ }
+
+ if (get_vm_area((unsigned long)map, &page1) ||
+ get_vm_area((unsigned long)map + page_size, &page2) ||
+ get_vm_area((unsigned long)map + page_size * 2, &page3)) {
+ printf("couldn't find mapping in /proc/self/maps\n");
+ goto out;
+ }
+
+ /* Now all three VMAs should be the same */
+ if (page1.start != page2.start || page2.start != page3.start) {
+ printf("failed to merge VMAs after munlock\n");
+ goto out;
+ }
+
+ ret = 0;
+out:
+ munmap(map, 3 * page_size);
+ return ret;
+}
+
+#ifndef MCL_ONFAULT
+#define MCL_ONFAULT (MCL_FUTURE << 1)
+#endif
+
+static int test_mlockall(int (test_function)(int flags))
+{
+ int ret = 1;
+
+ if (mlockall(MCL_ONFAULT)) {
+ perror("mlockall");
+ return ret;
+ }
+
+ ret = test_function(MAP_PRIVATE | MAP_ANONYMOUS);
+ munlockall();
+ return ret;
+}
+
+#ifndef MAP_LOCKONFAULT
+#define MAP_LOCKONFAULT (MAP_HUGETLB << 1)
+#endif
+
+int main(int argc, char **argv)
+{
+ int ret = 0;
+ ret += test_mmap(MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKONFAULT);
+ ret += test_mlockall(test_mmap);
+ ret += test_munlock(MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKONFAULT);
+ ret += test_mlockall(test_munlock);
+ ret += test_vma_management(MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKONFAULT);
+ ret += test_mlockall(test_vma_management);
+ return ret;
+}
diff -puN /dev/null tools/testing/selftests/vm/on-fault-limit.c
--- /dev/null
+++ a/tools/testing/selftests/vm/on-fault-limit.c
@@ -0,0 +1,47 @@
+#include <sys/mman.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#ifndef MCL_ONFAULT
+#define MCL_ONFAULT (MCL_FUTURE << 1)
+#endif
+
+static int test_limit(void)
+{
+ int ret = 1;
+ struct rlimit lims;
+ void *map;
+
+ if (getrlimit(RLIMIT_MEMLOCK, &lims)) {
+ perror("getrlimit");
+ return ret;
+ }
+
+ if (mlockall(MCL_ONFAULT)) {
+ perror("mlockall");
+ return ret;
+ }
+
+ map = mmap(NULL, 2 * lims.rlim_max, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, 0, 0);
+ if (map != MAP_FAILED)
+ printf("mmap should have failed, but didn't\n");
+ else {
+ ret = 0;
+ munmap(map, 2 * lims.rlim_max);
+ }
+
+ munlockall();
+ return ret;
+}
+
+int main(int argc, char **argv)
+{
+ int ret = 0;
+
+ ret += test_limit();
+ return ret;
+}
diff -puN tools/testing/selftests/vm/run_vmtests~selftests-vm-add-tests-for-lock-on-fault tools/testing/selftests/vm/run_vmtests
--- a/tools/testing/selftests/vm/run_vmtests~selftests-vm-add-tests-for-lock-on-fault
+++ a/tools/testing/selftests/vm/run_vmtests
@@ -102,4 +102,26 @@ else
echo "[PASS]"
fi
+echo "--------------------"
+echo "running lock-on-fault"
+echo "--------------------"
+./lock-on-fault
+if [ $? -ne 0 ]; then
+ echo "[FAIL]"
+ exitcode=1
+else
+ echo "[PASS]"
+fi
+
+echo "--------------------"
+echo "running on-fault-limit"
+echo "--------------------"
+sudo -u nobody ./on-fault-limit
+if [ $? -ne 0 ]; then
+ echo "[FAIL]"
+ exitcode=1
+else
+ echo "[PASS]"
+fi
+
exit $exitcode
_
Patches currently in -mm which might be from emunson@xxxxxxxxxx are
mm-mlock-refactor-mlock-munlock-and-munlockall-code.patch
mm-mlock-add-new-mlock-munlock-and-munlockall-system-calls.patch
mm-mlock-introduce-vm_lockonfault-and-add-mlock-flags-to-enable-it.patch
mm-mmap-add-mmap-flag-to-request-vm_lockonfault.patch
selftests-vm-add-tests-for-lock-on-fault.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
