[PATCH PART3 v4 0/6] staging: zcache/ramster: fix and ramster/debugfs improvement

[PATCH PART3 v4 0/6] staging: zcache/ramster: fix and ramster/debugfs improvement

[Wanpeng Li]

Changelog: 
 v3 -> v4:
  * fix compile issue 
 v2 -> v3:
  * update patch description of staging: ramster: Move debugfs code out of ramster.c file 
  * update patch title of staging: ramster/debug: Add RAMSTER_DEBUG Kconfig entry 
 v1 -> v2:  
  * fix bisect issue 
  * fix issue in patch staging: ramster: Provide accessory functions for counter decrease
  * drop patch staging: zcache: remove zcache_freeze 
  * Add Dan Acked-by

Fix bugs in zcache and rips out the debug counters out of ramster.c and 
sticks them in a debug.c file. Introduce accessory functions for counters 
increase/decrease, they are available when config RAMSTER_DEBUG, otherwise 
they are empty non-debug functions. Using an array to initialize/use debugfs 
attributes to make them neater. Dan Magenheimer confirm these works 
are needed. http://marc.info/?l=linux-mm&m=136535713106882&w=2

Patch 1~2 fix bugs in zcache

Patch 3~8 rips out the debug counters out of ramster.c and sticks them 
		  in a debug.c file 

Patch 9 fix coding style issue introduced in zcache2 cleanups 
        (s/int/bool + debugfs movement) patchset 

Patch 10 add how-to for ramster 

Dan Magenheimer (1):
	staging: ramster: add how-to for ramster
	
Wanpeng Li (5):
	staging: ramster: Move debugfs code out of ramster.c files
	staging: ramster/debug: Use an array to initialize/use debugfs attributes
	staging: ramster/debug: Add RAMSTER_DEBUG Kconfig entry
	staging: ramster: Add incremental accessory counters
	staging: zcache/debug: fix coding style

 drivers/staging/zcache/Kconfig           |    8 +
 drivers/staging/zcache/Makefile          |    1 +
 drivers/staging/zcache/debug.h           |   95 ++++++++---
 drivers/staging/zcache/ramster/HOWTO.txt |  257 ++++++++++++++++++++++++++++++
 drivers/staging/zcache/ramster/debug.c   |   66 ++++++++
 drivers/staging/zcache/ramster/debug.h   |  145 +++++++++++++++++
 drivers/staging/zcache/ramster/ramster.c |  147 +++--------------
 7 files changed, 574 insertions(+), 145 deletions(-)
 create mode 100644 drivers/staging/zcache/ramster/HOWTO.txt
 create mode 100644 drivers/staging/zcache/ramster/debug.c
 create mode 100644 drivers/staging/zcache/ramster/debug.h

-- 
1.7.10.4

[PATCH PART3 v4 1/6] staging: ramster: Move debugfs code out of ramster.c file

[Wanpeng Li]

Note that at this point there is no CONFIG_RAMSTER_DEBUG
option in the Kconfig. So in effect all of the counters
are nop until that option gets introduced in patch:
ramster/debug: Add CONFIG_RAMSTER_DEBUG Kconfig entry

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
 drivers/staging/zcache/Makefile          |    1 +
 drivers/staging/zcache/ramster/debug.c   |   70 ++++++++++++++++++
 drivers/staging/zcache/ramster/debug.h   |   78 ++++++++++++++++++++
 drivers/staging/zcache/ramster/ramster.c |  115 ++----------------------------
 4 files changed, 154 insertions(+), 110 deletions(-)
 create mode 100644 drivers/staging/zcache/ramster/debug.c
 create mode 100644 drivers/staging/zcache/ramster/debug.h

diff --git a/drivers/staging/zcache/Makefile b/drivers/staging/zcache/Makefile
index 24fd6aa..4956fa0 100644
--- a/drivers/staging/zcache/Makefile
+++ b/drivers/staging/zcache/Makefile
@@ -1,5 +1,6 @@
 zcache-y	:=		zcache-main.o tmem.o zbud.o
 zcache-$(CONFIG_ZCACHE_DEBUG) += debug.o
+zcache-$(CONFIG_RAMSTER) += ramster/debug.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/ramster.o ramster/r2net.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/nodemanager.o ramster/tcp.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/heartbeat.o ramster/masklog.o
diff --git a/drivers/staging/zcache/ramster/debug.c b/drivers/staging/zcache/ramster/debug.c
new file mode 100644
index 0000000..76861e4
--- /dev/null
+++ b/drivers/staging/zcache/ramster/debug.c
@@ -0,0 +1,70 @@
+#include <linux/atomic.h>
+#include "debug.h"
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#define zdfs    debugfs_create_size_t
+#define zdfs64  debugfs_create_u64
+
+ssize_t ramster_eph_pages_remoted;
+ssize_t ramster_pers_pages_remoted;
+ssize_t ramster_eph_pages_remote_failed;
+ssize_t ramster_pers_pages_remote_failed;
+ssize_t ramster_remote_eph_pages_succ_get;
+ssize_t ramster_remote_pers_pages_succ_get;
+ssize_t ramster_remote_eph_pages_unsucc_get;
+ssize_t ramster_remote_pers_pages_unsucc_get;
+ssize_t ramster_pers_pages_remote_nomem;
+ssize_t ramster_remote_objects_flushed;
+ssize_t ramster_remote_object_flushes_failed;
+ssize_t ramster_remote_pages_flushed;
+ssize_t ramster_remote_page_flushes_failed;
+
+int __init ramster_debugfs_init(void)
+{
+	struct dentry *root = debugfs_create_dir("ramster", NULL);
+	if (root == NULL)
+		return -ENXIO;
+
+	zdfs("eph_pages_remoted", S_IRUGO, root, &ramster_eph_pages_remoted);
+	zdfs("pers_pages_remoted", S_IRUGO, root, &ramster_pers_pages_remoted);
+	zdfs("eph_pages_remote_failed", S_IRUGO, root,
+		&ramster_eph_pages_remote_failed);
+	zdfs("pers_pages_remote_failed", S_IRUGO, root,
+		&ramster_pers_pages_remote_failed);
+	zdfs("remote_eph_pages_succ_get", S_IRUGO, root,
+		&ramster_remote_eph_pages_succ_get);
+	zdfs("remote_pers_pages_succ_get", S_IRUGO, root,
+		&ramster_remote_pers_pages_succ_get);
+	zdfs("remote_eph_pages_unsucc_get", S_IRUGO, root,
+		&ramster_remote_eph_pages_unsucc_get);
+	zdfs("remote_pers_pages_unsucc_get", S_IRUGO, root,
+		&ramster_remote_pers_pages_unsucc_get);
+	zdfs("pers_pages_remote_nomem", S_IRUGO, root,
+		&ramster_pers_pages_remote_nomem);
+	zdfs("remote_objects_flushed", S_IRUGO, root,
+		&ramster_remote_objects_flushed);
+	zdfs("remote_pages_flushed", S_IRUGO, root,
+		&ramster_remote_pages_flushed);
+	zdfs("remote_object_flushes_failed", S_IRUGO, root,
+		&ramster_remote_object_flushes_failed);
+	zdfs("remote_page_flushes_failed", S_IRUGO, root,
+		&ramster_remote_page_flushes_failed);
+	zdfs("foreign_eph_pages", S_IRUGO, root,
+		&ramster_foreign_eph_pages);
+	zdfs("foreign_eph_pages_max", S_IRUGO, root,
+		&ramster_foreign_eph_pages_max);
+	zdfs("foreign_pers_pages", S_IRUGO, root,
+		&ramster_foreign_pers_pages);
+	zdfs("foreign_pers_pages_max", S_IRUGO, root,
+		&ramster_foreign_pers_pages_max);
+	return 0;
+}
+#undef  zdebugfs
+#undef  zdfs64
+#else
+static inline int ramster_debugfs_init(void)
+{
+	return 0;
+}
+#endif
diff --git a/drivers/staging/zcache/ramster/debug.h b/drivers/staging/zcache/ramster/debug.h
new file mode 100644
index 0000000..3f608b7
--- /dev/null
+++ b/drivers/staging/zcache/ramster/debug.h
@@ -0,0 +1,78 @@
+#include <linux/bug.h>
+
+#ifdef CONFIG_RAMSTER
+
+extern long ramster_flnodes;
+static atomic_t ramster_flnodes_atomic = ATOMIC_INIT(0);
+static unsigned long ramster_flnodes_max;
+static inline void inc_ramster_flnodes(void)
+{
+	ramster_flnodes = atomic_inc_return(&ramster_flnodes_atomic);
+	if (ramster_flnodes > ramster_flnodes_max)
+		ramster_flnodes_max = ramster_flnodes;
+}
+static inline void dec_ramster_flnodes(void)
+{
+	ramster_flnodes = atomic_dec_return(&ramster_flnodes_atomic);
+}
+extern ssize_t ramster_foreign_eph_pages;
+static atomic_t ramster_foreign_eph_pages_atomic = ATOMIC_INIT(0);
+static ssize_t ramster_foreign_eph_pages_max;
+static inline void inc_ramster_foreign_eph_pages(void)
+{
+	ramster_foreign_eph_pages = atomic_inc_return(
+		&ramster_foreign_eph_pages_atomic);
+	if (ramster_foreign_eph_pages > ramster_foreign_eph_pages_max)
+		ramster_foreign_eph_pages_max = ramster_foreign_eph_pages;
+}
+static inline void dec_ramster_foreign_eph_pages(void)
+{
+	ramster_foreign_eph_pages = atomic_dec_return(
+		&ramster_foreign_eph_pages_atomic);
+}
+extern ssize_t ramster_foreign_pers_pages;
+static atomic_t ramster_foreign_pers_pages_atomic = ATOMIC_INIT(0);
+static ssize_t ramster_foreign_pers_pages_max;
+static inline void inc_ramster_foreign_pers_pages(void)
+{
+	ramster_foreign_pers_pages = atomic_inc_return(
+		&ramster_foreign_pers_pages_atomic);
+	if (ramster_foreign_pers_pages > ramster_foreign_pers_pages_max)
+		ramster_foreign_pers_pages_max = ramster_foreign_pers_pages;
+}
+static inline void dec_ramster_foreign_pers_pages(void)
+{
+	ramster_foreign_pers_pages = atomic_dec_return(
+		&ramster_foreign_pers_pages_atomic);
+}
+
+extern ssize_t ramster_eph_pages_remoted;
+extern ssize_t ramster_pers_pages_remoted;
+extern ssize_t ramster_eph_pages_remote_failed;
+extern ssize_t ramster_pers_pages_remote_failed;
+extern ssize_t ramster_remote_eph_pages_succ_get;
+extern ssize_t ramster_remote_pers_pages_succ_get;
+extern ssize_t ramster_remote_eph_pages_unsucc_get;
+extern ssize_t ramster_remote_pers_pages_unsucc_get;
+extern ssize_t ramster_pers_pages_remote_nomem;
+extern ssize_t ramster_remote_objects_flushed;
+extern ssize_t ramster_remote_object_flushes_failed;
+extern ssize_t ramster_remote_pages_flushed;
+extern ssize_t ramster_remote_page_flushes_failed;
+
+int ramster_debugfs_init(void);
+
+#else
+
+static inline void inc_ramster_flnodes(void) { };
+static inline void dec_ramster_flnodes(void) { };
+static inline void inc_ramster_foreign_eph_pages(void) { };
+static inline void dec_ramster_foreign_eph_pages(void) { };
+static inline void inc_ramster_foreign_pers_pages(void) { };
+static inline void dec_ramster_foreign_pers_pages(void) { };
+
+static inline int ramster_debugfs_init(void)
+{
+	return 0;
+}
+#endif
diff --git a/drivers/staging/zcache/ramster/ramster.c b/drivers/staging/zcache/ramster/ramster.c
index 444189e..1d29f5b 100644
--- a/drivers/staging/zcache/ramster/ramster.c
+++ b/drivers/staging/zcache/ramster/ramster.c
@@ -42,6 +42,7 @@
 #include "ramster.h"
 #include "ramster_nodemanager.h"
 #include "tcp.h"
+#include "debug.h"
 
 #define RAMSTER_TESTING
 
@@ -63,118 +64,12 @@ static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0);
 static bool ramster_nodes_manual_up[MANUAL_NODES] __read_mostly;
 static int ramster_remote_target_nodenum __read_mostly = -1;
 
-/* these counters are made available via debugfs */
-static long ramster_flnodes;
-static atomic_t ramster_flnodes_atomic = ATOMIC_INIT(0);
-static unsigned long ramster_flnodes_max;
-static inline void inc_ramster_flnodes(void)
-{
-	ramster_flnodes = atomic_inc_return(&ramster_flnodes_atomic);
-	if (ramster_flnodes > ramster_flnodes_max)
-		ramster_flnodes_max = ramster_flnodes;
-}
-static inline void dec_ramster_flnodes(void)
-{
-	ramster_flnodes = atomic_dec_return(&ramster_flnodes_atomic);
-}
-static ssize_t ramster_foreign_eph_pages;
-static atomic_t ramster_foreign_eph_pages_atomic = ATOMIC_INIT(0);
-static ssize_t ramster_foreign_eph_pages_max;
-static inline void inc_ramster_foreign_eph_pages(void)
-{
-	ramster_foreign_eph_pages = atomic_inc_return(
-			&ramster_foreign_eph_pages_atomic);
-	if (ramster_foreign_eph_pages > ramster_foreign_eph_pages_max)
-		ramster_foreign_eph_pages_max = ramster_foreign_eph_pages;
-}
-static inline void dec_ramster_foreign_eph_pages(void)
-{
-	ramster_foreign_eph_pages = atomic_dec_return(
-			&ramster_foreign_eph_pages_atomic);
-}
-static ssize_t ramster_foreign_pers_pages;
-static atomic_t ramster_foreign_pers_pages_atomic = ATOMIC_INIT(0);
-static ssize_t ramster_foreign_pers_pages_max;
-static inline void inc_ramster_foreign_pers_pages(void)
-{
-	ramster_foreign_pers_pages = atomic_inc_return(
-		&ramster_foreign_pers_pages_atomic);
-	if (ramster_foreign_pers_pages > ramster_foreign_pers_pages_max)
-		ramster_foreign_pers_pages_max = ramster_foreign_pers_pages;
-}
-static inline void dec_ramster_foreign_pers_pages(void)
-{
-	ramster_foreign_pers_pages = atomic_dec_return(
-		&ramster_foreign_pers_pages_atomic);
-}
-static ssize_t ramster_eph_pages_remoted;
-static ssize_t ramster_pers_pages_remoted;
-static ssize_t ramster_eph_pages_remote_failed;
-static ssize_t ramster_pers_pages_remote_failed;
-static ssize_t ramster_remote_eph_pages_succ_get;
-static ssize_t ramster_remote_pers_pages_succ_get;
-static ssize_t ramster_remote_eph_pages_unsucc_get;
-static ssize_t ramster_remote_pers_pages_unsucc_get;
-static ssize_t ramster_pers_pages_remote_nomem;
-static ssize_t ramster_remote_objects_flushed;
-static ssize_t ramster_remote_object_flushes_failed;
-static ssize_t ramster_remote_pages_flushed;
-static ssize_t ramster_remote_page_flushes_failed;
+/* Used by this code. */
+long ramster_flnodes;
+ssize_t ramster_foreign_eph_pages;
+ssize_t ramster_foreign_pers_pages;
 /* FIXME frontswap selfshrinking knobs in debugfs? */
 
-#ifdef CONFIG_DEBUG_FS
-#include <linux/debugfs.h>
-#define	zdfs	debugfs_create_size_t
-#define	zdfs64	debugfs_create_u64
-static int __init ramster_debugfs_init(void)
-{
-	struct dentry *root = debugfs_create_dir("ramster", NULL);
-	if (root == NULL)
-		return -ENXIO;
-
-	zdfs("eph_pages_remoted", S_IRUGO, root, &ramster_eph_pages_remoted);
-	zdfs("pers_pages_remoted", S_IRUGO, root, &ramster_pers_pages_remoted);
-	zdfs("eph_pages_remote_failed", S_IRUGO, root,
-			&ramster_eph_pages_remote_failed);
-	zdfs("pers_pages_remote_failed", S_IRUGO, root,
-			&ramster_pers_pages_remote_failed);
-	zdfs("remote_eph_pages_succ_get", S_IRUGO, root,
-			&ramster_remote_eph_pages_succ_get);
-	zdfs("remote_pers_pages_succ_get", S_IRUGO, root,
-			&ramster_remote_pers_pages_succ_get);
-	zdfs("remote_eph_pages_unsucc_get", S_IRUGO, root,
-			&ramster_remote_eph_pages_unsucc_get);
-	zdfs("remote_pers_pages_unsucc_get", S_IRUGO, root,
-			&ramster_remote_pers_pages_unsucc_get);
-	zdfs("pers_pages_remote_nomem", S_IRUGO, root,
-			&ramster_pers_pages_remote_nomem);
-	zdfs("remote_objects_flushed", S_IRUGO, root,
-			&ramster_remote_objects_flushed);
-	zdfs("remote_pages_flushed", S_IRUGO, root,
-			&ramster_remote_pages_flushed);
-	zdfs("remote_object_flushes_failed", S_IRUGO, root,
-			&ramster_remote_object_flushes_failed);
-	zdfs("remote_page_flushes_failed", S_IRUGO, root,
-			&ramster_remote_page_flushes_failed);
-	zdfs("foreign_eph_pages", S_IRUGO, root,
-			&ramster_foreign_eph_pages);
-	zdfs("foreign_eph_pages_max", S_IRUGO, root,
-			&ramster_foreign_eph_pages_max);
-	zdfs("foreign_pers_pages", S_IRUGO, root,
-			&ramster_foreign_pers_pages);
-	zdfs("foreign_pers_pages_max", S_IRUGO, root,
-			&ramster_foreign_pers_pages_max);
-	return 0;
-}
-#undef	zdebugfs
-#undef	zdfs64
-#else
-static inline int ramster_debugfs_init(void)
-{
-	return 0;
-}
-#endif
-
 static LIST_HEAD(ramster_rem_op_list);
 static DEFINE_SPINLOCK(ramster_rem_op_list_lock);
 static DEFINE_PER_CPU(struct ramster_preload, ramster_preloads);
-- 
1.7.10.4

[PATCH PART3 v4 2/6] staging: ramster/debug: Use an array to initialize/use debugfs attributes

[Wanpeng Li]

Use an array to initialize/use debugfs attributes, it makes them 
neater as zcache/debug.c does.

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
 drivers/staging/zcache/ramster/debug.c |   68 +++++++++++++++-----------------
 1 file changed, 32 insertions(+), 36 deletions(-)

diff --git a/drivers/staging/zcache/ramster/debug.c b/drivers/staging/zcache/ramster/debug.c
index 76861e4..bf34133 100644
--- a/drivers/staging/zcache/ramster/debug.c
+++ b/drivers/staging/zcache/ramster/debug.c
@@ -3,8 +3,6 @@
 
 #ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
-#define zdfs    debugfs_create_size_t
-#define zdfs64  debugfs_create_u64
 
 ssize_t ramster_eph_pages_remoted;
 ssize_t ramster_pers_pages_remoted;
@@ -20,48 +18,46 @@ ssize_t ramster_remote_object_flushes_failed;
 ssize_t ramster_remote_pages_flushed;
 ssize_t ramster_remote_page_flushes_failed;
 
+#define ATTR(x)  { .name = #x, .val = &ramster_##x, }
+static struct debug_entry {
+	const char *name;
+	ssize_t *val;
+} attrs[] = {
+	ATTR(eph_pages_remoted),
+	ATTR(pers_pages_remoted),
+	ATTR(eph_pages_remote_failed),
+	ATTR(pers_pages_remote_failed),
+	ATTR(remote_eph_pages_succ_get),
+	ATTR(remote_pers_pages_succ_get),
+	ATTR(remote_eph_pages_unsucc_get),
+	ATTR(remote_pers_pages_unsucc_get),
+	ATTR(pers_pages_remote_nomem),
+	ATTR(remote_objects_flushed),
+	ATTR(remote_pages_flushed),
+	ATTR(remote_object_flushes_failed),
+	ATTR(remote_page_flushes_failed),
+	ATTR(foreign_eph_pages),
+	ATTR(foreign_eph_pages_max),
+	ATTR(foreign_pers_pages),
+	ATTR(foreign_pers_pages_max),
+};
+#undef ATTR
+
 int __init ramster_debugfs_init(void)
 {
+	int i;
 	struct dentry *root = debugfs_create_dir("ramster", NULL);
 	if (root == NULL)
 		return -ENXIO;
 
-	zdfs("eph_pages_remoted", S_IRUGO, root, &ramster_eph_pages_remoted);
-	zdfs("pers_pages_remoted", S_IRUGO, root, &ramster_pers_pages_remoted);
-	zdfs("eph_pages_remote_failed", S_IRUGO, root,
-		&ramster_eph_pages_remote_failed);
-	zdfs("pers_pages_remote_failed", S_IRUGO, root,
-		&ramster_pers_pages_remote_failed);
-	zdfs("remote_eph_pages_succ_get", S_IRUGO, root,
-		&ramster_remote_eph_pages_succ_get);
-	zdfs("remote_pers_pages_succ_get", S_IRUGO, root,
-		&ramster_remote_pers_pages_succ_get);
-	zdfs("remote_eph_pages_unsucc_get", S_IRUGO, root,
-		&ramster_remote_eph_pages_unsucc_get);
-	zdfs("remote_pers_pages_unsucc_get", S_IRUGO, root,
-		&ramster_remote_pers_pages_unsucc_get);
-	zdfs("pers_pages_remote_nomem", S_IRUGO, root,
-		&ramster_pers_pages_remote_nomem);
-	zdfs("remote_objects_flushed", S_IRUGO, root,
-		&ramster_remote_objects_flushed);
-	zdfs("remote_pages_flushed", S_IRUGO, root,
-		&ramster_remote_pages_flushed);
-	zdfs("remote_object_flushes_failed", S_IRUGO, root,
-		&ramster_remote_object_flushes_failed);
-	zdfs("remote_page_flushes_failed", S_IRUGO, root,
-		&ramster_remote_page_flushes_failed);
-	zdfs("foreign_eph_pages", S_IRUGO, root,
-		&ramster_foreign_eph_pages);
-	zdfs("foreign_eph_pages_max", S_IRUGO, root,
-		&ramster_foreign_eph_pages_max);
-	zdfs("foreign_pers_pages", S_IRUGO, root,
-		&ramster_foreign_pers_pages);
-	zdfs("foreign_pers_pages_max", S_IRUGO, root,
-		&ramster_foreign_pers_pages_max);
+	for (i = 0; i < ARRAY_SIZE(attrs); i++)
+		if (!debugfs_create_size_t(attrs[i].name,
+				S_IRUGO, root, attrs[i].val))
+			goto out;
 	return 0;
+out:
+	return -ENODEV;
 }
-#undef  zdebugfs
-#undef  zdfs64
 #else
 static inline int ramster_debugfs_init(void)
 {
-- 
1.7.10.4

[PATCH PART3 v4 3/6] staging: ramster: Add incremental accessory counters

[Wanpeng Li]

Add incremental accessory counters that are going to be used for 
debug fs entries.

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>

---
 drivers/staging/zcache/ramster/debug.h   |   67 ++++++++++++++++++++++++++++++
 drivers/staging/zcache/ramster/ramster.c |   32 +++++++-------
 2 files changed, 83 insertions(+), 16 deletions(-)

diff --git a/drivers/staging/zcache/ramster/debug.h b/drivers/staging/zcache/ramster/debug.h
index 3f608b7..4428c79 100644
--- a/drivers/staging/zcache/ramster/debug.h
+++ b/drivers/staging/zcache/ramster/debug.h
@@ -62,6 +62,59 @@ extern ssize_t ramster_remote_page_flushes_failed;
 
 int ramster_debugfs_init(void);
 
+static inline void inc_ramster_eph_pages_remoted(void)
+{
+	ramster_eph_pages_remoted++;
+};
+static inline void inc_ramster_pers_pages_remoted(void)
+{
+	ramster_pers_pages_remoted++;
+};
+static inline void inc_ramster_eph_pages_remote_failed(void)
+{
+	ramster_eph_pages_remote_failed++;
+};
+static inline void inc_ramster_pers_pages_remote_failed(void)
+{
+	ramster_pers_pages_remote_failed++;
+};
+static inline void inc_ramster_remote_eph_pages_succ_get(void)
+{
+	ramster_remote_eph_pages_succ_get++;
+};
+static inline void inc_ramster_remote_pers_pages_succ_get(void)
+{
+	ramster_remote_pers_pages_succ_get++;
+};
+static inline void inc_ramster_remote_eph_pages_unsucc_get(void)
+{
+	ramster_remote_eph_pages_unsucc_get++;
+};
+static inline void inc_ramster_remote_pers_pages_unsucc_get(void)
+{
+	ramster_remote_pers_pages_unsucc_get++;
+};
+static inline void inc_ramster_pers_pages_remote_nomem(void)
+{
+	ramster_pers_pages_remote_nomem++;
+};
+static inline void inc_ramster_remote_objects_flushed(void)
+{
+	ramster_remote_objects_flushed++;
+};
+static inline void inc_ramster_remote_object_flushes_failed(void)
+{
+	ramster_remote_object_flushes_failed++;
+};
+static inline void inc_ramster_remote_pages_flushed(void)
+{
+	ramster_remote_pages_flushed++;
+};
+static inline void inc_ramster_remote_page_flushes_failed(void)
+{
+	ramster_remote_page_flushes_failed++;
+};
+
 #else
 
 static inline void inc_ramster_flnodes(void) { };
@@ -71,6 +124,20 @@ static inline void dec_ramster_foreign_eph_pages(void) { };
 static inline void inc_ramster_foreign_pers_pages(void) { };
 static inline void dec_ramster_foreign_pers_pages(void) { };
 
+static inline void inc_ramster_eph_pages_remoted(void) { };
+static inline void inc_ramster_pers_pages_remoted(void) { };
+static inline void inc_ramster_eph_pages_remote_failed(void) { };
+static inline void inc_ramster_pers_pages_remote_failed(void) { };
+static inline void inc_ramster_remote_eph_pages_succ_get(void) { };
+static inline void inc_ramster_remote_pers_pages_succ_get(void) { };
+static inline void inc_ramster_remote_eph_pages_unsucc_get(void) { };
+static inline void inc_ramster_remote_pers_pages_unsucc_get(void) { };
+static inline void inc_ramster_pers_pages_remote_nomem(void) { };
+static inline void inc_ramster_remote_objects_flushed(void) { };
+static inline void inc_ramster_remote_object_flushes_failed(void) { };
+static inline void inc_ramster_remote_pages_flushed(void) { };
+static inline void inc_ramster_remote_page_flushes_failed(void) { };
+
 static inline int ramster_debugfs_init(void)
 {
 	return 0;
diff --git a/drivers/staging/zcache/ramster/ramster.c b/drivers/staging/zcache/ramster/ramster.c
index 1d29f5b..8781627 100644
--- a/drivers/staging/zcache/ramster/ramster.c
+++ b/drivers/staging/zcache/ramster/ramster.c
@@ -156,9 +156,9 @@ int ramster_localify(int pool_id, struct tmem_oid *oidp, uint32_t index,
 		pr_err("UNTESTED pampd==NULL in ramster_localify\n");
 #endif
 		if (eph)
-			ramster_remote_eph_pages_unsucc_get++;
+			inc_ramster_remote_eph_pages_unsucc_get();
 		else
-			ramster_remote_pers_pages_unsucc_get++;
+			inc_ramster_remote_pers_pages_unsucc_get();
 		obj = NULL;
 		goto finish;
 	} else if (unlikely(!pampd_is_remote(pampd))) {
@@ -167,9 +167,9 @@ int ramster_localify(int pool_id, struct tmem_oid *oidp, uint32_t index,
 		pr_err("UNTESTED dup while waiting in ramster_localify\n");
 #endif
 		if (eph)
-			ramster_remote_eph_pages_unsucc_get++;
+			inc_ramster_remote_eph_pages_unsucc_get();
 		else
-			ramster_remote_pers_pages_unsucc_get++;
+			inc_ramster_remote_pers_pages_unsucc_get();
 		obj = NULL;
 		pampd = NULL;
 		ret = -EEXIST;
@@ -178,7 +178,7 @@ int ramster_localify(int pool_id, struct tmem_oid *oidp, uint32_t index,
 		/* no remote data, delete the local is_remote pampd */
 		pampd = NULL;
 		if (eph)
-			ramster_remote_eph_pages_unsucc_get++;
+			inc_ramster_remote_eph_pages_unsucc_get();
 		else
 			BUG();
 		delete = true;
@@ -209,9 +209,9 @@ int ramster_localify(int pool_id, struct tmem_oid *oidp, uint32_t index,
 	BUG_ON(extra == NULL);
 	zcache_decompress_to_page(data, size, (struct page *)extra);
 	if (eph)
-		ramster_remote_eph_pages_succ_get++;
+		inc_ramster_remote_eph_pages_succ_get();
 	else
-		ramster_remote_pers_pages_succ_get++;
+		inc_ramster_remote_pers_pages_succ_get();
 	ret = 0;
 finish:
 	tmem_localify_finish(obj, index, pampd, saved_hb, delete);
@@ -296,7 +296,7 @@ void *ramster_pampd_repatriate_preload(void *pampd, struct tmem_pool *pool,
 		c = atomic_dec_return(&ramster_remote_pers_pages);
 		WARN_ON_ONCE(c < 0);
 	} else {
-		ramster_pers_pages_remote_nomem++;
+		inc_ramster_pers_pages_remote_nomem();
 	}
 	local_irq_restore(flags);
 out:
@@ -435,9 +435,9 @@ static void ramster_remote_flush_page(struct flushlist_node *flnode)
 	remotenode = flnode->xh.client_id;
 	ret = r2net_remote_flush(xh, remotenode);
 	if (ret >= 0)
-		ramster_remote_pages_flushed++;
+		inc_ramster_remote_pages_flushed();
 	else
-		ramster_remote_page_flushes_failed++;
+		inc_ramster_remote_page_flushes_failed();
 	preempt_enable_no_resched();
 	ramster_flnode_free(flnode, NULL);
 }
@@ -452,9 +452,9 @@ static void ramster_remote_flush_object(struct flushlist_node *flnode)
 	remotenode = flnode->xh.client_id;
 	ret = r2net_remote_flush_object(xh, remotenode);
 	if (ret >= 0)
-		ramster_remote_objects_flushed++;
+		inc_ramster_remote_objects_flushed();
 	else
-		ramster_remote_object_flushes_failed++;
+		inc_ramster_remote_object_flushes_failed();
 	preempt_enable_no_resched();
 	ramster_flnode_free(flnode, NULL);
 }
@@ -505,18 +505,18 @@ int ramster_remotify_pageframe(bool eph)
 		 * But count them so we know if it becomes a problem.
 		 */
 			if (eph)
-				ramster_eph_pages_remote_failed++;
+				inc_ramster_eph_pages_remote_failed();
 			else
-				ramster_pers_pages_remote_failed++;
+				inc_ramster_pers_pages_remote_failed();
 			break;
 		} else {
 			if (!eph)
 				atomic_inc(&ramster_remote_pers_pages);
 		}
 		if (eph)
-			ramster_eph_pages_remoted++;
+			inc_ramster_eph_pages_remoted();
 		else
-			ramster_pers_pages_remoted++;
+			inc_ramster_pers_pages_remoted();
 		/*
 		 * data was successfully remoted so change the local version to
 		 * point to the remote node where it landed
-- 
1.7.10.4

[PATCH PART3 v4 4/6] staging: ramster/debug: Add CONFIG_RAMSTER_DEBUG Kconfig entry

[Wanpeng Li]

Add CONFIG_RAMSTER_DEBUG Kconfig entry.

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
 drivers/staging/zcache/Kconfig         |    8 ++++++++
 drivers/staging/zcache/Makefile        |    2 +-
 drivers/staging/zcache/ramster/debug.h |    2 +-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/zcache/Kconfig b/drivers/staging/zcache/Kconfig
index c3b8a10..05e87a1 100644
--- a/drivers/staging/zcache/Kconfig
+++ b/drivers/staging/zcache/Kconfig
@@ -33,6 +33,14 @@ config RAMSTER
 	  zcache2, compresses swap pages into local RAM, but then remotifies
 	  the compressed pages to another node in the RAMster cluster.
 
+config RAMSTER_DEBUG
+        bool "Enable ramster debug statistics"
+        depends on DEBUG_FS && RAMSTER
+        default n
+        help
+          This is used to provide an debugfs directory with counters of
+          how ramster is doing. You probably want to set this to 'N'.
+
 # Depends on not-yet-upstreamed mm patches to export end_swap_bio_write and
 # __add_to_swap_cache, and implement __swap_writepage (which is swap_writepage
 # without the frontswap call. When these are in-tree, the dependency on
diff --git a/drivers/staging/zcache/Makefile b/drivers/staging/zcache/Makefile
index 4956fa0..845a5c2 100644
--- a/drivers/staging/zcache/Makefile
+++ b/drivers/staging/zcache/Makefile
@@ -1,6 +1,6 @@
 zcache-y	:=		zcache-main.o tmem.o zbud.o
 zcache-$(CONFIG_ZCACHE_DEBUG) += debug.o
-zcache-$(CONFIG_RAMSTER) += ramster/debug.o
+zcache-$(CONFIG_RAMSTER_DEBUG) += ramster/debug.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/ramster.o ramster/r2net.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/nodemanager.o ramster/tcp.o
 zcache-$(CONFIG_RAMSTER)	+=	ramster/heartbeat.o ramster/masklog.o
diff --git a/drivers/staging/zcache/ramster/debug.h b/drivers/staging/zcache/ramster/debug.h
index 4428c79..5ffab50 100644
--- a/drivers/staging/zcache/ramster/debug.h
+++ b/drivers/staging/zcache/ramster/debug.h
@@ -1,6 +1,6 @@
 #include <linux/bug.h>
 
-#ifdef CONFIG_RAMSTER
+#ifdef CONFIG_RAMSTER_DEBUG
 
 extern long ramster_flnodes;
 static atomic_t ramster_flnodes_atomic = ATOMIC_INIT(0);
-- 
1.7.10.4

[PATCH PART3 v4 5/6] staging: zcache/debug: fix coding style

[Wanpeng Li]

Fix coding style issue: ERROR: space prohibited before that '++' (ctx:WxO)
and line beyond 8 characters.

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
 drivers/staging/zcache/debug.h |   95 ++++++++++++++++++++++++++++++++--------
 1 file changed, 76 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/zcache/debug.h b/drivers/staging/zcache/debug.h
index ddad92f..8088d28 100644
--- a/drivers/staging/zcache/debug.h
+++ b/drivers/staging/zcache/debug.h
@@ -174,26 +174,83 @@ extern ssize_t zcache_writtenback_pages;
 extern ssize_t zcache_outstanding_writeback_pages;
 #endif
 
-static inline void inc_zcache_flush_total(void) { zcache_flush_total ++; };
-static inline void inc_zcache_flush_found(void) { zcache_flush_found ++; };
-static inline void inc_zcache_flobj_total(void) { zcache_flobj_total ++; };
-static inline void inc_zcache_flobj_found(void) { zcache_flobj_found ++; };
-static inline void inc_zcache_failed_eph_puts(void) { zcache_failed_eph_puts ++; };
-static inline void inc_zcache_failed_pers_puts(void) { zcache_failed_pers_puts ++; };
-static inline void inc_zcache_failed_getfreepages(void) { zcache_failed_getfreepages ++; };
-static inline void inc_zcache_failed_alloc(void) { zcache_failed_alloc ++; };
-static inline void inc_zcache_put_to_flush(void) { zcache_put_to_flush ++; };
-static inline void inc_zcache_compress_poor(void) { zcache_compress_poor ++; };
-static inline void inc_zcache_mean_compress_poor(void) { zcache_mean_compress_poor ++; };
-static inline void inc_zcache_eph_ate_tail(void) { zcache_eph_ate_tail ++; };
-static inline void inc_zcache_eph_ate_tail_failed(void) { zcache_eph_ate_tail_failed ++; };
-static inline void inc_zcache_pers_ate_eph(void) { zcache_pers_ate_eph ++; };
-static inline void inc_zcache_pers_ate_eph_failed(void) { zcache_pers_ate_eph_failed ++; };
-static inline void inc_zcache_evicted_eph_zpages(unsigned zpages) { zcache_evicted_eph_zpages += zpages; };
-static inline void inc_zcache_evicted_eph_pageframes(void) { zcache_evicted_eph_pageframes ++; };
+static inline void inc_zcache_flush_total(void)
+{
+	zcache_flush_total++;
+};
+static inline void inc_zcache_flush_found(void)
+{
+	zcache_flush_found++;
+};
+static inline void inc_zcache_flobj_total(void)
+{
+	zcache_flobj_total++;
+};
+static inline void inc_zcache_flobj_found(void)
+{
+	zcache_flobj_found++;
+};
+static inline void inc_zcache_failed_eph_puts(void)
+{
+	zcache_failed_eph_puts++;
+};
+static inline void inc_zcache_failed_pers_puts(void)
+{
+	zcache_failed_pers_puts++;
+};
+static inline void inc_zcache_failed_getfreepages(void)
+{
+	zcache_failed_getfreepages++;
+};
+static inline void inc_zcache_failed_alloc(void)
+{
+	zcache_failed_alloc++;
+};
+static inline void inc_zcache_put_to_flush(void)
+{
+	zcache_put_to_flush++;
+};
+static inline void inc_zcache_compress_poor(void)
+{
+	zcache_compress_poor++;
+};
+static inline void inc_zcache_mean_compress_poor(void)
+{
+	zcache_mean_compress_poor++;
+};
+static inline void inc_zcache_eph_ate_tail(void)
+{
+	zcache_eph_ate_tail++;
+};
+static inline void inc_zcache_eph_ate_tail_failed(void)
+{
+	zcache_eph_ate_tail_failed++;
+};
+static inline void inc_zcache_pers_ate_eph(void)
+{
+	zcache_pers_ate_eph++;
+};
+static inline void inc_zcache_pers_ate_eph_failed(void)
+{
+	zcache_pers_ate_eph_failed++;
+};
+static inline void inc_zcache_evicted_eph_zpages(unsigned zpages)
+{
+	zcache_evicted_eph_zpages += zpages;
+};
+static inline void inc_zcache_evicted_eph_pageframes(void)
+{
+	zcache_evicted_eph_pageframes++;
+};
 
-static inline void inc_zcache_eph_nonactive_puts_ignored(void) { zcache_eph_nonactive_puts_ignored ++; };
-static inline void inc_zcache_pers_nonactive_puts_ignored(void) { zcache_pers_nonactive_puts_ignored ++; };
+static inline void inc_zcache_eph_nonactive_puts_ignored(void)
+{
+	zcache_eph_nonactive_puts_ignored++;
+};
+static inline void inc_zcache_pers_nonactive_puts_ignored(void)
+{
+	zcache_pers_nonactive_puts_ignored++;
+};
 
 int zcache_debugfs_init(void);
 #else
-- 
1.7.10.4

[PATCH PART2 v4 6/6] staging: ramster: add how-to for ramster

[Wanpeng Li]

Add how-to for ramster.

Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Singed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
 drivers/staging/zcache/ramster/HOWTO.txt |  257 ++++++++++++++++++++++++++++++
 1 file changed, 257 insertions(+)
 create mode 100644 drivers/staging/zcache/ramster/HOWTO.txt

diff --git a/drivers/staging/zcache/ramster/HOWTO.txt b/drivers/staging/zcache/ramster/HOWTO.txt
new file mode 100644
index 0000000..a4ee979
--- /dev/null
+++ b/drivers/staging/zcache/ramster/HOWTO.txt
@@ -0,0 +1,257 @@
+Version: 130309
+ Dan Magenheimer <dan.magenheimer@oracle.com>
+
+This is a how-to document for RAMster.  It applies to the March 9, 2013
+version of RAMster, re-merged with the new zcache codebase, built and tested
+on the 3.9 tree and submitted for the staging tree for 3.9.
+
+Note that this document was created from notes taken earlier.  I would
+appreciate any feedback from anyone who follows the process as described
+to confirm that it works and to clarify any possible misunderstandings,
+or to report problems.
+
+A. PRELIMINARY
+
+1) Install two or more Linux systems that are known to work when upgraded
+   to a recent upstream Linux kernel version (e.g. v3.9).  I used Oracle
+   Linux 6 ("OL6") on two Dell Optiplex 790s.  Note that it should be possible
+   to use ocfs2 as a filesystem on your systems but this hasn't been
+   tested thoroughly, so if you do use ocfs2 and run into problems, please
+   report them.  Up to eight nodes should work, but not much testing has
+   been done with more than three nodes.
+
+On each system:
+
+2) Configure, build and install then boot Linux (e.g. 3.9), just to ensure it
+   can be done with an unmodified upstream kernel.  Confirm you booted
+   the upstream kernel with "uname -a".
+
+3) Install ramster-tools.  The src.rpm and an OL6 rpm are available
+   in this directory.  I'm not very good at userspace stuff and
+   would welcome any help in turning ramster-tools into more
+   distributable rpms/debs for a wider range of distros.
+
+B. BUILDING RAMSTER INTO THE KERNEL
+
+Do the following on each system:
+
+1) Ensure you have the new codebase for drivers/staging/zcache in your source.
+
+2) Change your .config to have:
+
+	CONFIG_CLEANCACHE=y
+	CONFIG_FRONTSWAP=y
+	CONFIG_STAGING=y
+	CONFIG_ZCACHE=y
+	CONFIG_RAMSTER=y
+
+   You may have to reconfigure your kernel multiple times to ensure
+   all of these are set properly.  I use:
+
+	# yes "" | make oldconfig
+
+   and then manually check the .config file to ensure my selections
+   have "taken".
+
+   Do not bother to build the kernel until you are certain all of
+   the above config selections will stick for the build.
+
+3) Build this kernel and "make install" so that you have a new kernel
+   in /etc/grub.conf
+
+4) Add "ramster" to the kernel boot line in /etc/grub.conf.
+
+5) Reboot and check dmesg to ensure there are some messages from ramster
+   and that "ramster_enabled=1" appears.
+
+	# dmesg | grep ramster
+
+   You should also see a lot of files in:
+
+	# ls /sys/kernel/debug/zcache
+	# ls /sys/kernel/debug/ramster
+
+   and a few files in:
+
+	# ls /sys/kernel/mm/ramster
+
+   RAMster now will act as a single-system zcache but doesn't yet
+   know anything about the cluster so can't do anything remotely.
+
+C. BUILDING THE RAMSTER CLUSTER
+
+This is the error prone part unless you are a clustering expert.  We need
+to describe the cluster in /etc/ramster.conf file and the init scripts
+that parse it are extremely picky about the syntax.
+
+1) Create the /etc/ramster.conf file and ensure it is identical
+   on both systems.  There is a good amount of similar documentation
+   for ocfs2 /etc/cluster.conf that can be googled for this, but I use:
+
+	cluster:
+		name = ramster
+		node_count = 2
+	node:
+		name = system1
+		cluster = ramster
+		number = 0
+		ip_address = my.ip.ad.r1
+		ip_port = 7777
+	node:
+		name = system2
+		cluster = ramster
+		number = 0
+		ip_address = my.ip.ad.r2
+		ip_port = 7777
+
+   You must ensure that the "name" field in the file exactly matches
+   the output of "hostname" on each system.  The following assumes
+   you use "ramster" as the name of your cluster.
+
+2) Enable the ramster service and configure it:
+
+	# chkconfig --add ramster
+	# service ramster configure
+
+   Set "load on boot" to "y", cluster to start is "ramster" (or whatever
+   name you chose in ramster.conf), heartbeat dead threshold as "500",
+   network idle timeout as "1000000".  Leave the others as default.
+
+4) Reboot.  After reboot, try:
+
+	# service ramster status
+
+   You should see "Checking ramster cluster ramster: Online".  If you do
+   not, something is wrong and RAMster will not work.  Note that you
+   should also see that the driver for "configfs" is loaded and mounted,
+   the driver for ocfs2_dlmfs is not loaded, and some numbers for network
+   parameters.  You will also see "Checking ramster heartbeat: Not active".
+   That's all OK.
+
+5) Now you need to start the cluster heartbeat; the cluster is not "up"
+   until all nodes detect a heartbeat.  Normally this is done via
+   a cluster filesystem, but you don't have one.  Some hack-y
+   code in RAMster can start it for you though if you tell it what
+   nodes are "up".  To enable it for nodes 0 and 1, do:
+
+	# echo 0 > /sys/kernel/mm/ramster/manual_node_up
+	# echo 1 > /sys/kernel/mm/ramster/manual_node_up
+
+   This must be done on ALL nodes.  I usually put these lines
+   in /etc/rc.local as otherwise I forget.  To confirm that
+   the cluster is now up, on both systems do:
+
+	# dmesg | grep ramster
+
+   You should see "Accepted connection" messages in dmesg after this.
+
+6) You must tell each node the node to which it should "remotify" pages.
+   For example if you have a three-node cluster and you want nodes
+   1 and 2 to be "clients" and node 0 to be the "memory server", then
+   on nodes 1 and 2, you do:
+
+	# echo 0 > /sys/kernel/mm/ramster/remote_target_nodenum
+
+   You should see "ramster: node N set as remotification target"
+   in dmesg.  Again, /etc/rc.local is a good place to put this
+   so you don't forget to do it at each boot.
+
+7) One more step:  By default, the RAMster code does not "remotify" any
+   pages; this is primarily for testing purposes, but sometimes it is
+   useful.  This may change in the future, but for now, you must:
+
+	# echo 1 > /sys/kernel/mm/ramster/pers_remotify_enable
+	# echo 1 > /sys/kernel/mm/ramster/eph_remotify_enable
+
+   The first enables remotifying swap (persistent, aka frontswap) pages,
+   the second enables remotifying of page cache (ephemeral, cleancache)
+   pages.
+
+   These lines can also be put in /etc/rc.local (AFTER the node_up
+   lines), or I often just put them at the beginning of my script that
+   runs a workload.
+
+8) Most testing has been done with both/all machines booted roughly
+   simultaneously.  Ideally, you should do this too unless you are
+   trying to break RAMster rather than just use it. ;-)
+
+D. TESTING RAMSTER
+
+1) Note that RAMster has no value unless pages get "remotified".  For
+   swap/frontswap/persistent pages, this doesn't happen unless/until
+   the workload would cause swapping to occur, at which point pages
+   are put into frontswap/zcache, and the remotification thread starts
+   working.  To get to the point where the system swaps, you either
+   need a workload for which the working set exceeds the RAM in the
+   system; or you need to somehow reduce the amount of RAM one of
+   the system sees.  This latter is easy when testing in a VM, but
+   harder on physical systems.  In some cases, "mem=xxxM" on the
+   kernel command line restricts memory, but for some values of xxx
+   my kernel fails to boot.  I may also try creating a fixed RAMdisk,
+   doing nothing with it, but ensuring that it eats up a fixed
+   amount of RAM.
+2) To see if RAMster is working, on the remote system, I do:
+
+	# watch -d 'cat /sys/kernel/debug/ramster/foreign_*'
+
+   to monitor the number (and max) ephemeral and persistent pages
+   that RAMster has sent.  If these stay at 0, RAMster is not working
+   either because the workload isn't creating enough memory pressure
+   or because "remotifying" isn't working.  On the system with the
+   workload, you can watch lots of useful information also, but beware
+   that you may be affecting the workload and performance.  I use
+	# watch ./watchme
+   where the watchme file contains:
+
+	for i in /sys/kernel/debug/zcache/evicted_buddied_pages \
+		/sys/kernel/debug/zcache/evicted_raw_pages \
+		/sys/kernel/debug/zcache/evicted_unbuddied_pages \
+		/sys/kernel/debug/zcache/zbud_curr_raw_pages \
+		/sys/kernel/debug/zcache/zbud_curr_zbytes \
+		/sys/kernel/debug/zcache/zbud_curr_zpages \
+		/sys/kernel/debug/ramster/eph_pages_remoted \
+		/sys/kernel/debug/ramster/remote_eph_pages_succ_get \
+		/sys/kernel/debug/ramster/remote_pers_pages_succ_get \
+		/sys/kernel/debug/frontswap/succ_puts
+	do
+		echo $i ": " $(cat $i)
+	done
+   And if you have debugfs mounted (as /sys/kernel/debug), you can
+   add to the watchme script some interesting counters in
+   /sys/kernel/debug/cleancache/* and /sys/kernel/debug/frontswap/*
+
+3) In v4, there are known issues in counting certain values.  As a result
+   you may see periodic warnings from the kernel.  Almost always you
+   will see "ramster: bad accounting for XXX".  There are also "WARN_ONCE"
+   messages.  If you see kernel warnings with a tombstone, please report
+   them.  They are harmless but reflect bugs that need to be eventually fixed.
+
+AUTOMATIC SWAP REPATRIATION
+
+You may notice that while the systems are idle, the foreign persistent
+page count on the remote machine slowly decreases.  This is because
+RAMster implements "frontswap selfshrinking":  When possible, swap
+pages that have been remotified are slowly repatriated to the local
+machine.  This is so that local RAM can be used when possible and
+so that, in case of remote machine crash, the probability of loss
+of data is reduced.
+
+REBOOTING / POWEROFF
+
+If a system is shut down while some of its swap pages still reside
+on a remote system, the system may lock up partially through the shutdown
+sequence.  This is because the network is shut down before the
+swap mechansim is shut down.  To avoid this annoying problem, simply
+shut off the swap subsystem before starting the shutdown sequence, e.g.:
+
+	# swapoff -a
+	# reboot
+
+
+CHANGELOG:
+v5-120214->120817: updated for merge into new zcache codebase
+v4-120126->v5-120214: updated for V5
+111227->v4-120126: added info on selfshrinking and rebooting
+111227->v4-120126: added more info for tracking RAMster stats
+111227->v4-120126: CONFIG_PREEMPT_NONE no longer necessary
+111227->v4-120126: cleancache now works completely so no need to disable it
-- 
1.7.10.4

Re: [PATCH PART2 v4 6/6] staging: ramster: add how-to for ramster

[Greg Kroah-Hartman]

On Sat, Apr 13, 2013 at 09:01:32PM +0800, Wanpeng Li wrote:
> Add how-to for ramster.
> 
> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
> Singed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
> ---
>  drivers/staging/zcache/ramster/HOWTO.txt |  257 ++++++++++++++++++++++++++++++
>  1 file changed, 257 insertions(+)
>  create mode 100644 drivers/staging/zcache/ramster/HOWTO.txt
> 
> diff --git a/drivers/staging/zcache/ramster/HOWTO.txt b/drivers/staging/zcache/ramster/HOWTO.txt
> new file mode 100644
> index 0000000..a4ee979
> --- /dev/null
> +++ b/drivers/staging/zcache/ramster/HOWTO.txt
> @@ -0,0 +1,257 @@
> +Version: 130309
> + Dan Magenheimer <dan.magenheimer@oracle.com>

If Dan wrote this, why are you listing yourself as the author of this
patch?

> +CHANGELOG:
> +v5-120214->120817: updated for merge into new zcache codebase
> +v4-120126->v5-120214: updated for V5
> +111227->v4-120126: added info on selfshrinking and rebooting
> +111227->v4-120126: added more info for tracking RAMster stats
> +111227->v4-120126: CONFIG_PREEMPT_NONE no longer necessary
> +111227->v4-120126: cleancache now works completely so no need to disable it

That is not needed in an in-kernel file, please remove it.

greg k-h