syscalls/madvise09.c: Use custom mount point instead of /sys/fs/cgroup/memory

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted
on /sys/fs/cgroup/memory:
------------------------------------------------------------
safe_macros.c:169: BROK: madvise09.c:175: mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang <[email protected]>

---
 testcases/kernel/syscalls/madvise/madvise09.c | 29 +++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +25 -4

index f744405..ef0fa3b 100644
@@ -53,12 +53,14 @@
 #include <errno.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <sys/mount.h>
 
 #include "tst_test.h"
 #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
 static char cgroup_path[PATH_MAX];
 static char tasks_path[PATH_MAX];
 static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
 {
 	if (cgroup_path[0] && !access(cgroup_path, F_OK))
 		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK) && rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
 }
 
 static void run(void)

@@ -316,10 +327,20 @@ static void setup(void)
 {
 	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			if (rmdir(MEMCG_PATH) == -1)
+				tst_res(TWARN | TERRNO, "Rmdir %s failed",
+					 MEMCG_PATH);
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
 	}
+	memcg_mounted = 1;
 
 	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
 		swap_accounting_enabled = 1;

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted on /sys/fs/cgroup/memory:

   ------------------------------------------------------------
   safe_macros.c:169: BROK: madvise09.c:175: mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
   ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang <[email protected]>

---
 testcases/kernel/syscalls/madvise/madvise09.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
 #include <errno.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <sys/mount.h>
 
 #include "tst_test.h"
 #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
 static char cgroup_path[PATH_MAX];
 static char tasks_path[PATH_MAX];
 static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
 {
 	if (cgroup_path[0] && !access(cgroup_path, F_OK))
 		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK) && rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
 }
 
 static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
 {
 	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
 	}
+	memcg_mounted = 1;
 
 	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
 		swap_accounting_enabled = 1;

Hi Jan,

Could you help me review this patch.

Thanks,
Xiao Yang

Quoted 78 lines · xiao yang

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted on /sys/fs/cgroup/memory:

   ------------------------------------------------------------
   safe_macros.c:169: BROK: madvise09.c:175:
   mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
   ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang <[email protected]>

---
 testcases/kernel/syscalls/madvise/madvise09.c | 26
 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
 #include <errno.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <sys/mount.h>
 
 #include "tst_test.h"
 #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
 static char cgroup_path[PATH_MAX];
 static char tasks_path[PATH_MAX];
 static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
 {
 	if (cgroup_path[0] && !access(cgroup_path, F_OK))
 		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK) && rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
 }
 
 static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
 {
 	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
 	}
+	memcg_mounted = 1;
 
 	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
 		swap_accounting_enabled = 1;

----- Original Message -----

Quoted 3 lines

Hi Jan,

Could you help me review this patch.

Hi,

I think it would be better to use existing mount, if it's already mounted. umount may fail with -EBUSY if the subsystem is already part of existing hierarchy.

Regards,
Jan

Quoted 79 lines

Thanks,
Xiao Yang

Quoted 76 lines · xiao yang

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted

    on /sys/fs/cgroup/memory:
    ------------------------------------------------------------
    safe_macros.c:169: BROK: madvise09.c:175:
    mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
    ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang<[email protected]>

---
  testcases/kernel/syscalls/madvise/madvise09.c | 26
  ++++++++++++++++++++++----
  1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
  #include<errno.h>
  #include<stdio.h>
  #include<ctype.h>
+#include<sys/mount.h>
 
  #include "tst_test.h"
  #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
  static char cgroup_path[PATH_MAX];
  static char tasks_path[PATH_MAX];
  static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
  {
  	if (cgroup_path[0]&&  !access(cgroup_path, F_OK))
  		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK)&&  rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
  }
 
  static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
  {
  	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
  	}
+	memcg_mounted = 1;
 

Quoted 5 lines

testcases/kernel/syscalls/madvise/madvise09.c static void setup(void) · line 343

Quoted 2 lines

testcases/kernel/syscalls/madvise/madvise09.c +0 -0

  	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
  		swap_accounting_enabled = 1;

.

Quoted 10 lines

----- Original Message -----

Quoted 3 lines

Hi Jan,

Could you help me review this patch.

Hi,

I think it would be better to use existing mount, if it's already mounted. umount may fail with -EBUSY if the subsystem is already part of existing hierarchy.

Hi Jan,

1) I want to run madvise09 on as many distros supporting memcg as possible.

2) The custom mount point is just created and mounted for running madvise09, and will be
released after finishing madvise09, so i think it doesn't affect
existing hierarchy.

Additionally,
i use custom mount point according to some tests(oom03, oom05,
cpuset01, etc.) on LTP.

Thanks,
Xiao Yang

Quoted 90 lines

Regards,
Jan

Quoted 79 lines

Thanks,
Xiao Yang

Quoted 76 lines · xiao yang

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted

    on /sys/fs/cgroup/memory:
    ------------------------------------------------------------
    safe_macros.c:169: BROK: madvise09.c:175:
    mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
    ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang<[email protected]>

---
  testcases/kernel/syscalls/madvise/madvise09.c | 26
  ++++++++++++++++++++++----
  1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
  #include<errno.h>
  #include<stdio.h>
  #include<ctype.h>
+#include<sys/mount.h>
 
  #include "tst_test.h"
  #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
  static char cgroup_path[PATH_MAX];
  static char tasks_path[PATH_MAX];
  static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
  {
  	if (cgroup_path[0]&&  !access(cgroup_path, F_OK))
  		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK)&&  rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
  }
 
  static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
  {
  	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
  	}
+	memcg_mounted = 1;
 

Quoted 5 lines

testcases/kernel/syscalls/madvise/madvise09.c static void setup(void) · line 343

Quoted 2 lines

testcases/kernel/syscalls/madvise/madvise09.c +0 -0

  	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
  		swap_accounting_enabled = 1;

.

----- Original Message -----

Quoted 10 lines · Jan Stancek

Quoted 9 lines

----- Original Message -----

Quoted 3 lines

Hi Jan,

Could you help me review this patch.

Hi,

I think it would be better to use existing mount, if it's already mounted. umount may fail with -EBUSY if the subsystem is already part of existing hierarchy.

Quoted 8 lines

Hi Jan,

1) I want to run madvise09 on as many distros supporting memcg as possible.

2) The custom mount point is just created and mounted for running madvise09, and will be
released after finishing madvise09, so i think it doesn't affect
existing hierarchy.

Here's example:

This is state of the system prior to madvise09:

# mkdir -p /tmp/1; mount -t cgroup -o memory,hugetlb none /tmp/1; echo $?
0

And now you run madvise09, that tries to mount "memory" cgroup, which is going to fail:

# mkdir -p /tmp/2; mount -t cgroup -o memory none /tmp/2; echo $?
mount: none is already mounted or /tmp/2 busy
        none is already mounted on /tmp/1
32

Quoted 3 lines

Additionally,
i use custom mount point according to some tests(oom03, oom05,
cpuset01, etc.) on LTP.

OK, so my example, though possible is likely not very common.

We are close to next LTP release, can this wait or is this a regression that should be addressed before release? (Adding Cyril to CC)

Regards,
Jan

Quoted 93 lines

Thanks,
Xiao Yang

Quoted 88 lines

Regards,
Jan

Quoted 79 lines

Thanks,
Xiao Yang

Quoted 76 lines · xiao yang

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted

     on /sys/fs/cgroup/memory:
     ------------------------------------------------------------
     safe_macros.c:169: BROK: madvise09.c:175:
     mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) failed: EROFS
     ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang<[email protected]>

---
   testcases/kernel/syscalls/madvise/madvise09.c | 26
   ++++++++++++++++++++++----
   1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
   #include<errno.h>
   #include<stdio.h>
   #include<ctype.h>
+#include<sys/mount.h>
 
   #include "tst_test.h"
   #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
   static char cgroup_path[PATH_MAX];
   static char tasks_path[PATH_MAX];
   static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
   {
   	if (cgroup_path[0]&&   !access(cgroup_path, F_OK))
   		rmdir(cgroup_path);
+
+	if (memcg_mounted) {
+		tst_res(TINFO, "Umount memory cgroup after testing");
+		SAFE_UMOUNT(MEMCG_PATH);
+		memcg_mounted = 0;
+	}
+
+	if (!access(MEMCG_PATH, F_OK)&&   rmdir(MEMCG_PATH))
+		tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
   }
 
   static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
   {
   	long int swap_total;
 
-	if (access(MEMCG_PATH, F_OK)) {
-		tst_brk(TCONF, "'" MEMCG_PATH
-			"' not present, CONFIG_MEMCG missing?");
+	SAFE_MKDIR(MEMCG_PATH, 0777);
+
+	tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+	if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+		if (errno == ENODEV) {
+			tst_brk(TCONF,
+				 "Memory cgroup was not configured in kernel");
+		}
+		tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
   	}
+	memcg_mounted = 1;
 

Quoted 4 lines

testcases/kernel/syscalls/madvise/madvise09.c static void setup(void) · line 343

Quoted 2 lines

testcases/kernel/syscalls/madvise/madvise09.c +0 -0

   	if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
   		swap_accounting_enabled = 1;

.

.

Quoted 29 lines · Jan Stancek

----- Original Message -----

Quoted 14 lines · Jan Stancek

Quoted 11 lines

----- Original Message -----

Quoted 3 lines

Hi Jan,

Could you help me review this patch.

Hi,

I think it would be better to use existing mount, if it's already mounted.
umount may fail with -EBUSY if the subsystem is already part of existing
hierarchy.

Hi Jan,

Quoted 7 lines

1) I want to run madvise09 on as many distros supporting memcg as possible.

2) The custom mount point is just created and mounted for running madvise09, and will be
released after finishing madvise09, so i think it doesn't affect
existing hierarchy.

Here's example:

This is state of the system prior to madvise09:

# mkdir -p /tmp/1; mount -t cgroup -o memory,hugetlb none /tmp/1; 
echo $?
0

Quoted 6 lines

And now you run madvise09, that tries to mount "memory" cgroup, which is going to fail:

# mkdir -p /tmp/2; mount -t cgroup -o memory none /tmp/2; echo $?
mount: none is already mounted or /tmp/2 busy
        none is already mounted on /tmp/1
32

Hi Jan,

Thanks for your detailed explanation.

According to documented behavior of cgroups [1], it seems that only a new cgroup
hierarchy with the same options of the existing hierarchy can be mounted sucessfully,
and mount with different options will fail and return EBUSY as expected.

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/cgroup-v1/cgroups.txt

Combinations of sucess:
-----------------------------------------------------------------------------

1) # mkdir -p /tmp/1; mount -t cgroup -o memory,hugetlb none /tmp/1; echo $?
0

   # mkdir -p /tmp/2; mount -t cgroup -o memory,hugetlb none /tmp/2; 
echo $?
   0
2) # mkdir -p /tmp/1; mount -t cgroup -o memory none /tmp/1; echo $?
   0
   # mkdir -p /tmp/2; mount -t cgroup -o memory none /tmp/2; echo $?
   0
----------------------------------------------------------------------------- 

Combinations of failure:
-----------------------------------------------------------------------------

3) # mkdir -p /tmp/1; mount -t cgroup -o memory,hugetlb none /tmp/1; echo $?
0

   # mkdir -p /tmp/2; mount -t cgroup -o memory none /tmp/2; echo $?
     mount: none is already mounted or /tmp/2 busy
            none is already mounted on /tmp/1
   32

4) # mkdir -p /tmp/1; mount -t cgroup -o memory none /tmp/1; echo $? 0

   # mkdir -p /tmp/2; mount -t cgroup -o memory,hugetlb none /tmp/2; 
echo $?
     mount: none is already mounted or /tmp/2 busy
            none is already mounted on /tmp/1
   32
----------------------------------------------------------------------------- 

I am not sure how to fix all errors.

Quoted 7 lines

Quoted 3 lines

Additionally,
i use custom mount point according to some tests(oom03, oom05,
cpuset01, etc.) on LTP.

OK, so my example, though possible is likely not very common.

We are close to next LTP release, can this wait or is this a regression that should be addressed before release? (Adding Cyril to CC)

I think we can hold it until LTP is released.

Thanks,
Xiao Yang.

Quoted 100 lines

Regards,
Jan

Quoted 94 lines

Thanks,
Xiao Yang

Quoted 89 lines

Regards,
Jan

Quoted 80 lines

Thanks,
Xiao Yang

Quoted 77 lines · xiao yang

1) on some distros(e.g. RHEL6), memory cgroup was supported and mounted on /cgroup/memory by default, but the test was skipped if /sys/fs/cgroup/memory did not exist.

2) We got the following error if memory cgroup wasn't mounted

     on /sys/fs/cgroup/memory:
     ------------------------------------------------------------
     safe_macros.c:169: BROK: madvise09.c:175:
     mkdir(/sys/fs/cgroup/memory/ltp_madvise09_16386/,0777) 
failed: EROFS
     ------------------------------------------------------------

We use custom mount point and mount memory cgroup on it manually to fix these issues.

Signed-off-by xiao yang<[email protected]>

---
   testcases/kernel/syscalls/madvise/madvise09.c | 26
   ++++++++++++++++++++++----
   1 file changed, 22 insertions(+), 4 deletions(-)

testcases/kernel/syscalls/madvise/madvise09.c +22 -4

index f744405..25cf81f 100644
@@ -53,12 +53,14 @@
   #include<errno.h>
   #include<stdio.h>
   #include<ctype.h>
+#include<sys/mount.h>
 
   #include "tst_test.h"
   #include "lapi/mmap.h"
 
-#define MEMCG_PATH "/sys/fs/cgroup/memory/"
+#define MEMCG_PATH "/dev/memcg_madvise09/"
 
+static int memcg_mounted;
   static char cgroup_path[PATH_MAX];
   static char tasks_path[PATH_MAX];
   static char limit_in_bytes_path[PATH_MAX];

@@ -277,6 +279,15 @@ static void cleanup(void)
   {
       if (cgroup_path[0]&&   !access(cgroup_path, F_OK))
           rmdir(cgroup_path);
+
+    if (memcg_mounted) {
+        tst_res(TINFO, "Umount memory cgroup after testing");
+        SAFE_UMOUNT(MEMCG_PATH);
+        memcg_mounted = 0;
+    }
+
+    if (!access(MEMCG_PATH, F_OK)&&   rmdir(MEMCG_PATH))
+        tst_res(TWARN | TERRNO, "Rmdir %s failed", MEMCG_PATH);
   }
 
   static void run(void)

@@ -316,10 +327,17 @@ static void setup(void)
   {
       long int swap_total;
 
-    if (access(MEMCG_PATH, F_OK)) {
-        tst_brk(TCONF, "'" MEMCG_PATH
-            "' not present, CONFIG_MEMCG missing?");
+    SAFE_MKDIR(MEMCG_PATH, 0777);
+
+    tst_res(TINFO, "Mount memory cgroup on %s", MEMCG_PATH);
+    if (mount("memcg", MEMCG_PATH, "cgroup", 0, "memory") == -1) {
+        if (errno == ENODEV) {
+            tst_brk(TCONF,
+                 "Memory cgroup was not configured in kernel");
+        }
+        tst_brk(TBROK | TERRNO, "Failed to mount memory cgroup");
       }
+    memcg_mounted = 1;
 

Quoted 4 lines

testcases/kernel/syscalls/madvise/madvise09.c static void setup(void) · line 343

Quoted 2 lines

testcases/kernel/syscalls/madvise/madvise09.c +0 -0

       if (!access(MEMCG_PATH "memory.memsw.limit_in_bytes", F_OK))
           swap_accounting_enabled = 1;

.

.

Adding Cyril to CC. :-)