From: Adam Litke <[EMAIL PROTECTED]>
This patch fixes two intertwined issues:
When the SHM_HUGETLB flag is passed to shmget(), the system default huge page
size is used to back the shared memory segment. Unlike with mmap() there is
not yet a way to use an alternate huge page size for shared memory segments.
This exception must be taken into account by the shmget override function -- it
cannot call gethugepagesize() but must discover the effective huge page size by
direct examination of /proc/meminfo. Make the shmoverride test case discover
the huge page size in the same manner.
The shmoverride_* test case does not always link against libhugetlbfs.
Therefore, it cannot use the new mechanism for manipulating pool counters.
Unfortunately, this means that the logic to read /proc/meminfo must be
duplicated in order for shmoverride_unlinked to build as a NOLIB test.
[EMAIL PROTECTED]: consolidate makefile updates in one place]
Signed-off-by: Adam Litke <[EMAIL PROTECTED]>
---
shm.c | 7 +++-
tests/shmoverride_unlinked.c | 74 ++++++++++++++++++++++++++++++++++++++----
2 files changed, 73 insertions(+), 8 deletions(-)
diff --git a/shm.c b/shm.c
index cc9995d..8a56725 100644
--- a/shm.c
+++ b/shm.c
@@ -56,7 +56,12 @@ int shmget(key_t key, size_t size, int shmflg)
/* Align the size and set SHM_HUGETLB on request */
if (hugetlbshm_enabled) {
- aligned_size = ALIGN(size, gethugepagesize());
+ /*
+ * Use /proc/meminfo because shm always uses the system
+ * default huge page size.
+ */
+ long hpage_size = read_meminfo("Hugepagesize:") * 1024;
+ aligned_size = ALIGN(size, hpage_size);
if (size != aligned_size) {
DEBUG("hugetlb_shmem: size growth align %zd -> %zd\n",
size, aligned_size);
diff --git a/tests/shmoverride_unlinked.c b/tests/shmoverride_unlinked.c
index a8af228..5813cb7 100644
--- a/tests/shmoverride_unlinked.c
+++ b/tests/shmoverride_unlinked.c
@@ -26,6 +26,7 @@
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
+#include <ctype.h>
#include <hugetlbfs.h>
#include "hugetests.h"
@@ -94,11 +95,55 @@ void _shmunmap(int s, int line)
}
#define shmunmap(s) _shmunmap(s, __LINE__)
+/*
+ * This test wants to manipulate the hugetlb pool without necessarily linking
+ * to libhugetlbfs so the helpers for doing this may not be available -- hence
+ * the duplicated versions below.
+ *
+ * NOTE: We use /proc/sys/vm/nr_hugepages and /proc/meminfo for writing and
+ * reading pool counters because shared memory will always use the system
+ * default huge page size regardless of any libhugetlbfs settings.
+ */
+#define MEMINFO_SIZE 2048
+long local_read_meminfo(const char *tag)
+{
+ int fd;
+ char buf[MEMINFO_SIZE];
+ int len, readerr;
+ char *p, *q;
+ long val;
+
+ fd = open("/proc/meminfo", O_RDONLY);
+ if (fd < 0)
+ FAIL("Couldn't open /proc/meminfo: %s\n", strerror(errno));
+
+ len = read(fd, buf, sizeof(buf));
+ readerr = errno;
+ close(fd);
+ if (len < 0)
+ FAIL("Error reading /proc/meminfo: %s\n", strerror(errno));
+
+ if (len == sizeof(buf))
+ FAIL("/proc/meminfo is too large\n");
+ buf[len] = '\0';
+
+ p = strstr(buf, tag);
+ if (!p)
+ FAIL("Tag %s not found in /proc/meminfo\n", tag);
+ p += strlen(tag);
+
+ val = strtol(p, &q, 0);
+ if (!isspace(*q))
+ FAIL("Couldn't parse /proc/meminfo\n");
+
+ return val;
+}
+
void setup_hugetlb_pool(unsigned long count)
{
FILE *fd;
unsigned long poolsize;
- count += read_meminfo("HugePages_Rsvd:");
+ count += local_read_meminfo("HugePages_Rsvd:");
fd = fopen("/proc/sys/vm/nr_hugepages", "w");
if (!fd)
CONFIG("Cannot open nr_hugepages for writing\n");
@@ -106,12 +151,19 @@ void setup_hugetlb_pool(unsigned long count)
fclose(fd);
/* Confirm the resize worked */
- poolsize = read_meminfo("HugePages_Total:");
+ poolsize = local_read_meminfo("HugePages_Total:");
if (poolsize != count)
FAIL("Failed to resize pool to %lu pages. Got %lu instead\n",
count, poolsize);
}
+void local_check_free_huge_pages(int needed_pages)
+{
+ int free = local_read_meminfo("HugePages_Free:");
+ if (free < needed_pages)
+ CONFIG("Must have at least %i free hugepages", needed_pages);
+}
+
void run_test(char *desc, int hpages, int bpages, int pool_nr, int expect_diff)
{
long resv_before, resv_after;
@@ -119,9 +171,9 @@ void run_test(char *desc, int hpages, int bpages, int
pool_nr, int expect_diff)
setup_hugetlb_pool(pool_nr);
/* untouched, shared mmap */
- resv_before = read_meminfo("HugePages_Rsvd:");
+ resv_before = local_read_meminfo("HugePages_Rsvd:");
shmmap(SL_TEST, hpages, bpages);
- resv_after = read_meminfo("HugePages_Rsvd:");
+ resv_after = local_read_meminfo("HugePages_Rsvd:");
memset(map_addr[SL_TEST], 0, map_size[SL_TEST]);
shmunmap(SL_TEST);
@@ -134,6 +186,14 @@ void run_test(char *desc, int hpages, int bpages, int
pool_nr, int expect_diff)
void cleanup(void)
{
+ int i;
+
+ /* Clean up any allocated shmids */
+ for (i = 0; i < NR_SLOTS; i++)
+ if (map_id[i] > 0)
+ shmctl(map_id[i], IPC_RMID, NULL);
+
+ /* Restore the pool size. */
if (saved_nr_hugepages >= 0)
setup_hugetlb_pool(saved_nr_hugepages);
}
@@ -142,15 +202,15 @@ int main(int argc, char **argv)
{
test_init(argc, argv);
check_must_be_root();
- check_free_huge_pages(POOL_SIZE);
- saved_nr_hugepages = read_meminfo("HugePages_Total:");
+ local_check_free_huge_pages(POOL_SIZE);
+ saved_nr_hugepages = local_read_meminfo("HugePages_Total:");
/*
* We cannot call check_hugepagesize because we are not linked to
* libhugetlbfs. This is a bit hacky but we are depending on earlier
* tests failing to catch when this wouldn't work
*/
- hpage_size = read_meminfo("Hugepagesize:") * 1024;
+ hpage_size = local_read_meminfo("Hugepagesize:") * 1024;
bpage_size = getpagesize();
/* Run the test with small pages */
--
1.6.0.1.451.gc8d31
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