The patch titled
Subject: khugepaged: replace the usage of system(3) in the test
has been added to the -mm tree. Its filename is
khugepaged-add-self-test-fix-2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/khugepaged-add-self-test-fix-2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/khugepaged-add-self-test-fix-2.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Subject: khugepaged: replace the usage of system(3) in the test
Some glibc version doesn't use CLONE_VM | CLONE_VFORK for system(3)
implementation and on such system, we find the test case fails. This is
due to fork() marking all the parent page table pages read-only to do a
COW.
Avoid the usage of system(3) in the test.
Link: http://lkml.kernel.org/r/20200429110727.89388-1-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/khugepaged.c | 105 ++++++++++++++++------
1 file changed, 77 insertions(+), 28 deletions(-)
--- a/tools/testing/selftests/vm/khugepaged.c~khugepaged-add-self-test-fix-2
+++ a/tools/testing/selftests/vm/khugepaged.c
@@ -21,6 +21,7 @@ static unsigned long page_size;
static int hpage_pmd_nr;
#define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/"
+#define PID_SMAPS "/proc/self/smaps"
enum thp_enabled {
THP_ALWAYS,
@@ -330,56 +331,104 @@ static void adjust_settings(void)
success("OK");
}
-#define CHECK_HUGE_FMT "sed -ne " \
- "'/^%lx/,/^AnonHugePages/{/^AnonHugePages:\\s*%ld kB/ q1}' " \
- "/proc/%d/smaps"
+#define MAX_LINE_LENGTH 500
-static bool check_huge(void *p)
+static bool check_for_pattern(FILE *fp, char *pattern, char *buf)
{
- char *cmd;
+ while (fgets(buf, MAX_LINE_LENGTH, fp) != NULL) {
+ if (!strncmp(buf, pattern, strlen(pattern)))
+ return true;
+ }
+ return false;
+}
+
+static bool check_huge(char *addr)
+{
+ bool thp = false;
int ret;
+ FILE *fp;
+ char buffer[MAX_LINE_LENGTH];
+ char addr_pattern[MAX_LINE_LENGTH];
- ret = asprintf(&cmd, CHECK_HUGE_FMT,
- (unsigned long)p, hpage_pmd_size >> 10, getpid());
- if (ret < 0) {
- perror("asprintf(CHECK_FMT)");
+ ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08llx-", addr);
+ if (ret >= MAX_LINE_LENGTH) {
+ printf("%s: Pattern is too long\n", __func__);
+ exit(EXIT_FAILURE);
+ }
+
+
+ fp = fopen(PID_SMAPS, "r");
+ if (!fp) {
+ printf("%s: Failed to open file %s\n", __func__, PID_SMAPS);
exit(EXIT_FAILURE);
}
+ if (!check_for_pattern(fp, addr_pattern, buffer))
+ goto err_out;
- ret = system(cmd);
- free(cmd);
- if (ret < 0 || !WIFEXITED(ret)) {
- perror("system(check_huge)");
+ ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "AnonHugePages:%10lld kB", hpage_pmd_size >> 10);
+ if (ret >= MAX_LINE_LENGTH) {
+ printf("%s: Pattern is too long\n", __func__);
exit(EXIT_FAILURE);
}
+ /*
+ * Fetch the AnonHugePages: in the same block and check whether it got
+ * the expected number of hugeepages next.
+ */
+ if (!check_for_pattern(fp, "AnonHugePages:", buffer))
+ goto err_out;
+
+ if (strncmp(buffer, addr_pattern, strlen(addr_pattern)))
+ goto err_out;
- return WEXITSTATUS(ret);
+ thp = true;
+err_out:
+ fclose(fp);
+ return thp;
}
-#define CHECK_SWAP_FMT "sed -ne " \
- "'/^%lx/,/^Swap:/{/^Swap:\\s*%ld kB/ q1}' " \
- "/proc/%d/smaps"
-static bool check_swap(void *p, unsigned long size)
+static bool check_swap(void *addr, unsigned long size)
{
- char *cmd;
+ bool swap = false;
int ret;
+ FILE *fp;
+ char buffer[MAX_LINE_LENGTH];
+ char addr_pattern[MAX_LINE_LENGTH];
- ret = asprintf(&cmd, CHECK_SWAP_FMT,
- (unsigned long)p, size >> 10, getpid());
- if (ret < 0) {
- perror("asprintf(CHECK_SWAP)");
+ ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08llx-", addr);
+ if (ret >= MAX_LINE_LENGTH) {
+ printf("%s: Pattern is too long\n", __func__);
+ exit(EXIT_FAILURE);
+ }
+
+
+ fp = fopen(PID_SMAPS, "r");
+ if (!fp) {
+ printf("%s: Failed to open file %s\n", __func__, PID_SMAPS);
exit(EXIT_FAILURE);
}
+ if (!check_for_pattern(fp, addr_pattern, buffer))
+ goto err_out;
- ret = system(cmd);
- free(cmd);
- if (ret < 0 || !WIFEXITED(ret)) {
- perror("system(check_swap)");
+ ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "Swap:%19lld kB", size >> 10);
+ if (ret >= MAX_LINE_LENGTH) {
+ printf("%s: Pattern is too long\n", __func__);
exit(EXIT_FAILURE);
}
+ /*
+ * Fetch the Swap: in the same block and check whether it got
+ * the expected number of hugeepages next.
+ */
+ if (!check_for_pattern(fp, "Swap:", buffer))
+ goto err_out;
+
+ if (strncmp(buffer, addr_pattern, strlen(addr_pattern)))
+ goto err_out;
- return WEXITSTATUS(ret);
+ swap = true;
+err_out:
+ fclose(fp);
+ return swap;
}
static void *alloc_mapping(void)
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are
khugepaged-add-self-test-fix-2.patch
