[LTP] [PATCH V2 1/3] mm/ksm: taking use of SAFE_FILE_ macro for ksm05.c

[LTP] [PATCH V2 1/3] mm/ksm: taking use of SAFE_FILE_ macro for ksm05.c

[Li Wang]

Signed-off-by: Li Wang <liwang@redhat.com>
---
 testcases/kernel/mem/ksm/ksm05.c | 32 +++-----------------------------
 1 file changed, 3 insertions(+), 29 deletions(-)

diff --git a/testcases/kernel/mem/ksm/ksm05.c b/testcases/kernel/mem/ksm/ksm05.c
index abf888e..2baca3b 100644
--- a/testcases/kernel/mem/ksm/ksm05.c
+++ b/testcases/kernel/mem/ksm/ksm05.c
@@ -75,7 +75,6 @@ int TST_TOTAL = 1;
 static int ksm_run_orig;
 
 static void sighandler(int sig);
-static void write_ksm_run(int val);
 
 int main(int argc, char *argv[])
 {
@@ -123,25 +122,8 @@ static void sighandler(int sig)
 	_exit((sig == SIGSEGV) ? 0 : sig);
 }
 
-static void write_ksm_run(int val)
-{
-	int fd;
-	char buf[BUFSIZ];
-
-	sprintf(buf, "%d", val);
-	fd = open(PATH_KSM "run", O_WRONLY);
-	if (fd == -1)
-		tst_brkm(TBROK | TERRNO, cleanup, "open");
-	if (write(fd, buf, 1) != 1)
-		tst_brkm(TBROK | TERRNO, cleanup, "write");
-	close(fd);
-}
-
 void setup(void)
 {
-	int fd;
-	char buf[BUFSIZ];
-
 	tst_require_root();
 
 	if (tst_kvercmp(2, 6, 32) < 0)
@@ -155,24 +137,16 @@ void setup(void)
 	TEST_PAUSE;
 
 	/* save original /sys/kernel/mm/ksm/run value */
-	fd = open(PATH_KSM "run", O_RDONLY);
-	if (fd == -1)
-		tst_brkm(TBROK | TERRNO, cleanup, "open");
-	if (read(fd, buf, 1) != 1)
-		tst_brkm(TBROK | TERRNO, cleanup, "read");
-	close(fd);
-	ksm_run_orig = atoi(buf);
+	SAFE_FILE_SCANF(NULL, PATH_KSM "run", "%d", &ksm_run_orig);
 
 	/* echo 1 > /sys/kernel/mm/ksm/run */
-	if (ksm_run_orig != 1)
-		write_ksm_run(1);
+	SAFE_FILE_PRINTF(NULL, PATH_KSM "run", "1");
 }
 
 void cleanup(void)
 {
 	/* restore /sys/kernel/mm/ksm/run value */
-	if (ksm_run_orig != 1)
-		write_ksm_run(ksm_run_orig);
+	FILE_PRINTF(PATH_KSM "run", "%d", ksm_run_orig);
 }
 #else
 int main(void)
-- 
1.8.3.1

[LTP] [PATCH V2 2/3] mm/ksm: extend 'max_page_sharing' before ksm testing

[Li Wang]

This kernel commit (de39e60a6, ksm: introduce ksm_max_page_sharing per page...)
introduced a new KSM sysfs knob '/sys/kernel/mm/ksm/max_page_sharing' in linux-next.

The runtime value of 'max_page_sharing' will affect pages_shared/pages_sharing,
because this enforces a deduplication limit to avoid the virtual memory rmap lists
to grow too large.

ltp/ksm0* tests can easily get failures on that kernel like:
-----
ksm01       0  TINFO  :  wait for all children to stop.
ksm01       0  TINFO  :  KSM merging...
ksm01       0  TINFO  :  resume all children.
ksm01       0  TINFO  :  child 2 stops.
...
ksm01       0  TINFO  :  run is 1.
ksm01       0  TINFO  :  pages_shared is 384.
ksm01       1  TFAIL  :  mem.c:238: pages_shared is not 2.
ksm01       0  TINFO  :  pages_sharing is 97920.
ksm01       2  TFAIL  :  mem.c:238: pages_sharing is not 98302.
ksm01       0  TINFO  :  pages_volatile is 0.
ksm01       0  TINFO  :  pages_unshared is 0.
ksm01       0  TINFO  :  sleep_millisecs is 0.
ksm01       0  TINFO  :  pages_to_scan is 98304.

This patch is intened to extend the 'max_page_sharing' value dynamically to
make tests pass.

Signed-off-by: Li Wang <liwang@redhat.com>
---
 testcases/kernel/mem/include/mem.h |  3 +++
 testcases/kernel/mem/ksm/ksm01.c   |  4 ++++
 testcases/kernel/mem/ksm/ksm02.c   |  3 +++
 testcases/kernel/mem/ksm/ksm03.c   |  4 ++++
 testcases/kernel/mem/ksm/ksm04.c   |  4 ++++
 testcases/kernel/mem/ksm/ksm06.c   |  4 ++++
 testcases/kernel/mem/lib/mem.c     | 22 +++++++++++++++++++++-
 7 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/testcases/kernel/mem/include/mem.h b/testcases/kernel/mem/include/mem.h
index 43988fe..69d08dd 100644
--- a/testcases/kernel/mem/include/mem.h
+++ b/testcases/kernel/mem/include/mem.h
@@ -43,7 +43,10 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill);
 /* KSM */
 
 #define PATH_KSM		"/sys/kernel/mm/ksm/"
+int max_page_sharing;
 
+void save_max_page_sharing(void);
+void restore_max_page_sharing(void);
 void test_ksm_merge_across_nodes(unsigned long nr_pages);
 
 /* THP */
diff --git a/testcases/kernel/mem/ksm/ksm01.c b/testcases/kernel/mem/ksm/ksm01.c
index b62df06..824881c 100644
--- a/testcases/kernel/mem/ksm/ksm01.c
+++ b/testcases/kernel/mem/ksm/ksm01.c
@@ -106,6 +106,8 @@ void setup(void)
 	if (access(PATH_KSM, F_OK) == -1)
 		tst_brkm(TCONF, NULL, "KSM configuration is not enabled");
 
+	save_max_page_sharing();
+
 	/*
 	 * kernel commit 90bd6fd introduced a new KSM sysfs knob
 	 * /sys/kernel/mm/ksm/merge_across_nodes, setting it to '0'
@@ -128,4 +130,6 @@ void cleanup(void)
 	if (access(PATH_KSM "merge_across_nodes", F_OK) == 0)
 		FILE_PRINTF(PATH_KSM "merge_across_nodes",
 				 "%d", merge_across_nodes);
+
+	restore_max_page_sharing();
 }
diff --git a/testcases/kernel/mem/ksm/ksm02.c b/testcases/kernel/mem/ksm/ksm02.c
index 537ec01..6274f8a 100644
--- a/testcases/kernel/mem/ksm/ksm02.c
+++ b/testcases/kernel/mem/ksm/ksm02.c
@@ -125,6 +125,8 @@ void cleanup(void)
 		FILE_PRINTF(PATH_KSM "merge_across_nodes",
 				 "%d", merge_across_nodes);
 
+	restore_max_page_sharing();
+
 	umount_mem(CPATH, CPATH_NEW);
 }
 
@@ -136,6 +138,7 @@ void setup(void)
 		tst_brkm(TCONF, NULL, "2.6.32 or greater kernel required");
 	if (access(PATH_KSM, F_OK) == -1)
 		tst_brkm(TCONF, NULL, "KSM configuration is not enabled");
+	save_max_page_sharing();
 
 	if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) {
 		SAFE_FILE_SCANF(NULL, PATH_KSM "merge_across_nodes",
diff --git a/testcases/kernel/mem/ksm/ksm03.c b/testcases/kernel/mem/ksm/ksm03.c
index b73e023..979222a 100644
--- a/testcases/kernel/mem/ksm/ksm03.c
+++ b/testcases/kernel/mem/ksm/ksm03.c
@@ -113,6 +113,8 @@ void setup(void)
 		SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1");
 	}
 
+	save_max_page_sharing();
+
 	mount_mem("memcg", "cgroup", "memory", MEMCG_PATH, MEMCG_PATH_NEW);
 	tst_sig(FORK, DEF_HANDLER, NULL);
 	TEST_PAUSE;
@@ -124,5 +126,7 @@ void cleanup(void)
 		FILE_PRINTF(PATH_KSM "merge_across_nodes",
 				 "%d", merge_across_nodes);
 
+	restore_max_page_sharing();
+
 	umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
 }
diff --git a/testcases/kernel/mem/ksm/ksm04.c b/testcases/kernel/mem/ksm/ksm04.c
index 0c1d4e0..4beeed6 100644
--- a/testcases/kernel/mem/ksm/ksm04.c
+++ b/testcases/kernel/mem/ksm/ksm04.c
@@ -127,6 +127,8 @@ void cleanup(void)
 		FILE_PRINTF(PATH_KSM "merge_across_nodes",
 				 "%d", merge_across_nodes);
 
+	restore_max_page_sharing();
+
 	umount_mem(CPATH, CPATH_NEW);
 	umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
 }
@@ -146,6 +148,8 @@ void setup(void)
 		SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1");
 	}
 
+	save_max_page_sharing();
+
 	tst_sig(FORK, DEF_HANDLER, cleanup);
 	TEST_PAUSE;
 	mount_mem("cpuset", "cpuset", NULL, CPATH, CPATH_NEW);
diff --git a/testcases/kernel/mem/ksm/ksm06.c b/testcases/kernel/mem/ksm/ksm06.c
index 02d304f..2092746 100644
--- a/testcases/kernel/mem/ksm/ksm06.c
+++ b/testcases/kernel/mem/ksm/ksm06.c
@@ -105,6 +105,8 @@ void setup(void)
 	SAFE_FILE_SCANF(NULL, PATH_KSM "sleep_millisecs",
 			"%d", &sleep_millisecs);
 
+	save_max_page_sharing();
+
 	tst_sig(FORK, DEF_HANDLER, cleanup);
 	TEST_PAUSE;
 }
@@ -116,6 +118,8 @@ void cleanup(void)
 	FILE_PRINTF(PATH_KSM "sleep_millisecs",
 			 "%d", sleep_millisecs);
 	FILE_PRINTF(PATH_KSM "run", "%d", run);
+
+	restore_max_page_sharing();
 }
 
 static void usage(void)
diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
index 7b5bb35..084e5a4 100644
--- a/testcases/kernel/mem/lib/mem.c
+++ b/testcases/kernel/mem/lib/mem.c
@@ -230,6 +230,20 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
 
 /* KSM */
 
+void save_max_page_sharing(void)
+{
+	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
+	        SAFE_FILE_SCANF(NULL, PATH_KSM "max_page_sharing",
+	                        "%d", &max_page_sharing);
+}
+
+void restore_max_page_sharing(void)
+{
+	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
+	        FILE_PRINTF(PATH_KSM "max_page_sharing",
+	                         "%d", max_page_sharing);
+}
+
 static void check(char *path, long int value)
 {
 	char fullpath[BUFSIZ];
@@ -502,9 +516,12 @@ void create_same_memory(int size, int num, int unit)
 	stop_ksm_children(child, num);
 
 	tst_resm(TINFO, "KSM merging...");
+	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
+		SAFE_FILE_PRINTF(cleanup, PATH_KSM "max_page_sharing",
+				"%ld", size * pages * num);
 	SAFE_FILE_PRINTF(cleanup, PATH_KSM "run", "1");
 	SAFE_FILE_PRINTF(cleanup, PATH_KSM "pages_to_scan", "%ld",
-			 size * pages *num);
+			 size * pages * num);
 	SAFE_FILE_PRINTF(cleanup, PATH_KSM "sleep_millisecs", "0");
 
 	resume_ksm_children(child, num);
@@ -595,6 +612,9 @@ void test_ksm_merge_across_nodes(unsigned long nr_pages)
 	SAFE_FILE_PRINTF(cleanup, PATH_KSM "sleep_millisecs", "0");
 	SAFE_FILE_PRINTF(cleanup, PATH_KSM "pages_to_scan", "%ld",
 			 nr_pages * num_nodes);
+	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
+		SAFE_FILE_PRINTF(cleanup, PATH_KSM "max_page_sharing",
+			"%ld", nr_pages * num_nodes);
 	/*
 	 * merge_across_nodes setting can be changed only when there
 	 * are no ksm shared pages in system, so set run 2 to unmerge
-- 
1.8.3.1

[LTP] [PATCH V2 3/3] mm/oom: enable ksm before OOM-KSM testing

[Li Wang]

In the alloc_mem() function, the memory flag is set to 'MADV_MERGEABLE',
	if (testcase == KSM && madvise(s, length, MADV_MERGEABLE) == -1)
			return errno;
But it still doesn't send the whole item for test, unless the ksm is enabled.

Generally, the '../ksm/run' default is 0, it should be changed to 1 to activate ksm.

Signed-off-by: Li Wang <liwang@redhat.com>
---
 testcases/kernel/mem/lib/mem.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
index 084e5a4..1200d1d 100644
--- a/testcases/kernel/mem/lib/mem.c
+++ b/testcases/kernel/mem/lib/mem.c
@@ -211,6 +211,8 @@ static void set_global_mempolicy(int mempolicy)
 
 void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
 {
+	int ksm_run_orig;
+
 	set_global_mempolicy(mempolicy);
 
 	tst_resm(TINFO, "start normal OOM testing.");
@@ -224,7 +226,10 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
 			 "skip OOM test for KSM pags");
 	} else {
 		tst_resm(TINFO, "start OOM testing for KSM pages.");
+		SAFE_FILE_SCANF(cleanup, PATH_KSM "run", "%d", &ksm_run_orig);
+		SAFE_FILE_PRINTF(cleanup, PATH_KSM "run", "1");
 		oom(KSM, lite, retcode, allow_sigkill);
+		SAFE_FILE_PRINTF(cleanup,PATH_KSM "run", "%d", ksm_run_orig);
 	}
 }
 
-- 
1.8.3.1

[LTP] [PATCH V2 2/3] mm/ksm: extend 'max_page_sharing' before ksm testing

[Cyril Hrubis]

Hi!
>  testcases/kernel/mem/include/mem.h |  3 +++
>  testcases/kernel/mem/ksm/ksm01.c   |  4 ++++
>  testcases/kernel/mem/ksm/ksm02.c   |  3 +++
>  testcases/kernel/mem/ksm/ksm03.c   |  4 ++++
>  testcases/kernel/mem/ksm/ksm04.c   |  4 ++++
>  testcases/kernel/mem/ksm/ksm06.c   |  4 ++++
>  testcases/kernel/mem/lib/mem.c     | 22 +++++++++++++++++++++-
>  7 files changed, 43 insertions(+), 1 deletion(-)
> 
> diff --git a/testcases/kernel/mem/include/mem.h b/testcases/kernel/mem/include/mem.h
> index 43988fe..69d08dd 100644
> --- a/testcases/kernel/mem/include/mem.h
> +++ b/testcases/kernel/mem/include/mem.h
> @@ -43,7 +43,10 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill);
>  /* KSM */
>  
>  #define PATH_KSM		"/sys/kernel/mm/ksm/"
> +int max_page_sharing;

This value is not modified outside the library. It makes no sense to
declare it in the header.

As a matter of fact it would be far better to declare it as static int
inside the library so that there is no chance that it will be modified
by the testcases.

> +void save_max_page_sharing(void);
> +void restore_max_page_sharing(void);
>  void test_ksm_merge_across_nodes(unsigned long nr_pages);
>  
>  /* THP */
> diff --git a/testcases/kernel/mem/ksm/ksm01.c b/testcases/kernel/mem/ksm/ksm01.c
> index b62df06..824881c 100644
> --- a/testcases/kernel/mem/ksm/ksm01.c
> +++ b/testcases/kernel/mem/ksm/ksm01.c
> @@ -106,6 +106,8 @@ void setup(void)
>  	if (access(PATH_KSM, F_OK) == -1)
>  		tst_brkm(TCONF, NULL, "KSM configuration is not enabled");
>  
> +	save_max_page_sharing();
> +
>  	/*
>  	 * kernel commit 90bd6fd introduced a new KSM sysfs knob
>  	 * /sys/kernel/mm/ksm/merge_across_nodes, setting it to '0'
> @@ -128,4 +130,6 @@ void cleanup(void)
>  	if (access(PATH_KSM "merge_across_nodes", F_OK) == 0)
>  		FILE_PRINTF(PATH_KSM "merge_across_nodes",
>  				 "%d", merge_across_nodes);
> +
> +	restore_max_page_sharing();
>  }
> diff --git a/testcases/kernel/mem/ksm/ksm02.c b/testcases/kernel/mem/ksm/ksm02.c
> index 537ec01..6274f8a 100644
> --- a/testcases/kernel/mem/ksm/ksm02.c
> +++ b/testcases/kernel/mem/ksm/ksm02.c
> @@ -125,6 +125,8 @@ void cleanup(void)
>  		FILE_PRINTF(PATH_KSM "merge_across_nodes",
>  				 "%d", merge_across_nodes);
>  
> +	restore_max_page_sharing();
> +
>  	umount_mem(CPATH, CPATH_NEW);
>  }
>  
> @@ -136,6 +138,7 @@ void setup(void)
>  		tst_brkm(TCONF, NULL, "2.6.32 or greater kernel required");
>  	if (access(PATH_KSM, F_OK) == -1)
>  		tst_brkm(TCONF, NULL, "KSM configuration is not enabled");
> +	save_max_page_sharing();
>  
>  	if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) {
>  		SAFE_FILE_SCANF(NULL, PATH_KSM "merge_across_nodes",
> diff --git a/testcases/kernel/mem/ksm/ksm03.c b/testcases/kernel/mem/ksm/ksm03.c
> index b73e023..979222a 100644
> --- a/testcases/kernel/mem/ksm/ksm03.c
> +++ b/testcases/kernel/mem/ksm/ksm03.c
> @@ -113,6 +113,8 @@ void setup(void)
>  		SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1");
>  	}
>  
> +	save_max_page_sharing();
> +
>  	mount_mem("memcg", "cgroup", "memory", MEMCG_PATH, MEMCG_PATH_NEW);
>  	tst_sig(FORK, DEF_HANDLER, NULL);
>  	TEST_PAUSE;
> @@ -124,5 +126,7 @@ void cleanup(void)
>  		FILE_PRINTF(PATH_KSM "merge_across_nodes",
>  				 "%d", merge_across_nodes);
>  
> +	restore_max_page_sharing();
> +
>  	umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
>  }
> diff --git a/testcases/kernel/mem/ksm/ksm04.c b/testcases/kernel/mem/ksm/ksm04.c
> index 0c1d4e0..4beeed6 100644
> --- a/testcases/kernel/mem/ksm/ksm04.c
> +++ b/testcases/kernel/mem/ksm/ksm04.c
> @@ -127,6 +127,8 @@ void cleanup(void)
>  		FILE_PRINTF(PATH_KSM "merge_across_nodes",
>  				 "%d", merge_across_nodes);
>  
> +	restore_max_page_sharing();
> +
>  	umount_mem(CPATH, CPATH_NEW);
>  	umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
>  }
> @@ -146,6 +148,8 @@ void setup(void)
>  		SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1");
>  	}
>  
> +	save_max_page_sharing();
> +
>  	tst_sig(FORK, DEF_HANDLER, cleanup);
>  	TEST_PAUSE;
>  	mount_mem("cpuset", "cpuset", NULL, CPATH, CPATH_NEW);
> diff --git a/testcases/kernel/mem/ksm/ksm06.c b/testcases/kernel/mem/ksm/ksm06.c
> index 02d304f..2092746 100644
> --- a/testcases/kernel/mem/ksm/ksm06.c
> +++ b/testcases/kernel/mem/ksm/ksm06.c
> @@ -105,6 +105,8 @@ void setup(void)
>  	SAFE_FILE_SCANF(NULL, PATH_KSM "sleep_millisecs",
>  			"%d", &sleep_millisecs);
>  
> +	save_max_page_sharing();
> +
>  	tst_sig(FORK, DEF_HANDLER, cleanup);
>  	TEST_PAUSE;
>  }
> @@ -116,6 +118,8 @@ void cleanup(void)
>  	FILE_PRINTF(PATH_KSM "sleep_millisecs",
>  			 "%d", sleep_millisecs);
>  	FILE_PRINTF(PATH_KSM "run", "%d", run);
> +
> +	restore_max_page_sharing();
>  }
>  
>  static void usage(void)
> diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
> index 7b5bb35..084e5a4 100644
> --- a/testcases/kernel/mem/lib/mem.c
> +++ b/testcases/kernel/mem/lib/mem.c
> @@ -230,6 +230,20 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
>  
>  /* KSM */
>  
> +void save_max_page_sharing(void)
> +{
> +	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
> +	        SAFE_FILE_SCANF(NULL, PATH_KSM "max_page_sharing",
> +	                        "%d", &max_page_sharing);
> +}
> +
> +void restore_max_page_sharing(void)
> +{
> +	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
> +	        FILE_PRINTF(PATH_KSM "max_page_sharing",
> +	                         "%d", max_page_sharing);
> +}
> +
>  static void check(char *path, long int value)
>  {
>  	char fullpath[BUFSIZ];
> @@ -502,9 +516,12 @@ void create_same_memory(int size, int num, int unit)
>  	stop_ksm_children(child, num);
>  
>  	tst_resm(TINFO, "KSM merging...");
> +	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
> +		SAFE_FILE_PRINTF(cleanup, PATH_KSM "max_page_sharing",
> +				"%ld", size * pages * num);
>  	SAFE_FILE_PRINTF(cleanup, PATH_KSM "run", "1");
>  	SAFE_FILE_PRINTF(cleanup, PATH_KSM "pages_to_scan", "%ld",
> -			 size * pages *num);
> +			 size * pages * num);
>  	SAFE_FILE_PRINTF(cleanup, PATH_KSM "sleep_millisecs", "0");
>  
>  	resume_ksm_children(child, num);
> @@ -595,6 +612,9 @@ void test_ksm_merge_across_nodes(unsigned long nr_pages)
>  	SAFE_FILE_PRINTF(cleanup, PATH_KSM "sleep_millisecs", "0");
>  	SAFE_FILE_PRINTF(cleanup, PATH_KSM "pages_to_scan", "%ld",
>  			 nr_pages * num_nodes);
> +	if (access(PATH_KSM "max_page_sharing", F_OK) == 0)
> +		SAFE_FILE_PRINTF(cleanup, PATH_KSM "max_page_sharing",
> +			"%ld", nr_pages * num_nodes);
>  	/*
>  	 * merge_across_nodes setting can be changed only when there
>  	 * are no ksm shared pages in system, so set run 2 to unmerge

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH V2 3/3] mm/oom: enable ksm before OOM-KSM testing

[Cyril Hrubis]

Hi!
>  void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
>  {
> +	int ksm_run_orig;
> +
>  	set_global_mempolicy(mempolicy);
>  
>  	tst_resm(TINFO, "start normal OOM testing.");
> @@ -224,7 +226,10 @@ void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
>  			 "skip OOM test for KSM pags");
>  	} else {
>  		tst_resm(TINFO, "start OOM testing for KSM pages.");
> +		SAFE_FILE_SCANF(cleanup, PATH_KSM "run", "%d", &ksm_run_orig);
> +		SAFE_FILE_PRINTF(cleanup, PATH_KSM "run", "1");
>  		oom(KSM, lite, retcode, allow_sigkill);
> +		SAFE_FILE_PRINTF(cleanup,PATH_KSM "run", "%d", ksm_run_orig);
                                         ^
					 missing space

Technically the oom() can actually exit the test execution (calls
tst_brkm()) so it would be a bit better if the value was restored in the
test cleanup. But I guess that it's unlikely to happen and we can
proceed with this patch.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH V2 2/3] mm/ksm: extend 'max_page_sharing' before ksm testing

[Li Wang]

On Thu, Mar 31, 2016 at 9:31 PM, Cyril Hrubis <chrubis@suse.cz> wrote:

> Hi!
> >  testcases/kernel/mem/include/mem.h |  3 +++
> >  testcases/kernel/mem/ksm/ksm01.c   |  4 ++++
> >  testcases/kernel/mem/ksm/ksm02.c   |  3 +++
> >  testcases/kernel/mem/ksm/ksm03.c   |  4 ++++
> >  testcases/kernel/mem/ksm/ksm04.c   |  4 ++++
> >  testcases/kernel/mem/ksm/ksm06.c   |  4 ++++
> >  testcases/kernel/mem/lib/mem.c     | 22 +++++++++++++++++++++-
> >  7 files changed, 43 insertions(+), 1 deletion(-)
> >
> > diff --git a/testcases/kernel/mem/include/mem.h
> b/testcases/kernel/mem/include/mem.h
> > index 43988fe..69d08dd 100644
> > --- a/testcases/kernel/mem/include/mem.h
> > +++ b/testcases/kernel/mem/include/mem.h
> > @@ -43,7 +43,10 @@ void testoom(int mempolicy, int lite, int retcode,
> int allow_sigkill);
> >  /* KSM */
> >
> >  #define PATH_KSM             "/sys/kernel/mm/ksm/"
> > +int max_page_sharing;
>
> This value is not modified outside the library. It makes no sense to
> declare it in the header.
>
> As a matter of fact it would be far better to declare it as static int
> inside the library so that there is no chance that it will be modified
> by the testcases.
>

sounds good, could you help to fix that, or need I format a patch next
version?


-- 
Regards,
Li Wang
Email: liwang@redhat.com
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[LTP] [PATCH V2 3/3] mm/oom: enable ksm before OOM-KSM testing

[Li Wang]

On Thu, Mar 31, 2016 at 9:52 PM, Cyril Hrubis <chrubis@suse.cz> wrote:

> Hi!
> >  void testoom(int mempolicy, int lite, int retcode, int allow_sigkill)
> >  {
> > +     int ksm_run_orig;
> > +
> >       set_global_mempolicy(mempolicy);
> >
> >       tst_resm(TINFO, "start normal OOM testing.");
> > @@ -224,7 +226,10 @@ void testoom(int mempolicy, int lite, int retcode,
> int allow_sigkill)
> >                        "skip OOM test for KSM pags");
> >       } else {
> >               tst_resm(TINFO, "start OOM testing for KSM pages.");
> > +             SAFE_FILE_SCANF(cleanup, PATH_KSM "run", "%d",
> &ksm_run_orig);
> > +             SAFE_FILE_PRINTF(cleanup, PATH_KSM "run", "1");
> >               oom(KSM, lite, retcode, allow_sigkill);
> > +             SAFE_FILE_PRINTF(cleanup,PATH_KSM "run", "%d",
> ksm_run_orig);
>                                          ^
>                                          missing space
>
> Technically the oom() can actually exit the test execution (calls
> tst_brkm()) so it would be a bit better if the value was restored in the
> test cleanup. But I guess that it's unlikely to happen and we can
> proceed with this patch.
>

hmm, right. To be honest, before I go this way, I took a consideration that
if we can enable the ksm in oom*.c codes, but looks like mm library(mem.c)
achieves so many functions for the oom test, and it will mix with other oom
special test if do like that.

Anyway, with the patch applied, oom + ksm PASS on kernel-4.4 currently.
------------------------------
oom01       0  TINFO  :  start OOM testing for KSM pages.
oom01       0  TINFO  :  expected victim is 1044.
oom01       0  TINFO  :  thread (7f6b8e4df700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8dcde700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8bcda700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8c4db700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8b4d9700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8ccdc700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8d4dd700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8e4df700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8bcda700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8c4db700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8dcde700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8ccdc700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8b4d9700), allocating 3221225472 bytes.
oom01       0  TINFO  :  thread (7f6b8d4dd700), allocating 3221225472 bytes.
oom01       5  TPASS  :  victim signalled: (9) SIGKILL
oom01       0  TINFO  :  set overcommit_memory to 0



-- 
Regards,
Li Wang
Email: liwang@redhat.com
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[LTP] [PATCH V2 2/3] mm/ksm: extend 'max_page_sharing' before ksm testing

[Cyril Hrubis]

Hi!
> sounds good, could you help to fix that, or need I format a patch next
> version?

Patchset pushed with the change I proposed, thanks.

-- 
Cyril Hrubis
chrubis@suse.cz