[PATCH 1/3 v2 staging-next] android: Collect statistics from lowmemorykiller

From: peter enderborg
Date: Thu Feb 09 2017 - 10:54:43 EST


This collects stats for shrinker calls and how much
waste work we do within the lowmemorykiller.

Signed-off-by: Peter Enderborg <peter.enderborg@xxxxxxxxxxxxxx>
---
drivers/staging/android/Kconfig | 11 ++++
drivers/staging/android/Makefile | 1 +
drivers/staging/android/lowmemorykiller.c | 9 ++-
drivers/staging/android/lowmemorykiller_stats.c | 85 +++++++++++++++++++++++++
drivers/staging/android/lowmemorykiller_stats.h | 29 +++++++++
5 files changed, 134 insertions(+), 1 deletion(-)
create mode 100644 drivers/staging/android/lowmemorykiller_stats.c
create mode 100644 drivers/staging/android/lowmemorykiller_stats.h

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 6c00d6f..96e86c7 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -24,6 +24,17 @@ config ANDROID_LOW_MEMORY_KILLER
scripts (/init.rc), and it defines priority values with minimum free memory size
for each priority.

+config ANDROID_LOW_MEMORY_KILLER_STATS
+ bool "Android Low Memory Killer: collect statistics"
+ depends on ANDROID_LOW_MEMORY_KILLER
+ default n
+ help
+ Create a file in /proc/lmkstats that includes
+ collected statistics about kills, scans and counts
+ and interaction with the shrinker. Its content
+ will be different depeding on lmk implementation used.
+
+
source "drivers/staging/android/ion/Kconfig"

endif # if ANDROID
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 7ed1be7..d710eb2 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -4,3 +4,4 @@ obj-y += ion/

obj-$(CONFIG_ASHMEM) += ashmem.o
obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER) += lowmemorykiller.o
+obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER_STATS) += lowmemorykiller_stats.o
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index ec3b665..15c1b38 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -42,6 +42,7 @@
#include <linux/rcupdate.h>
#include <linux/profile.h>
#include <linux/notifier.h>
+#include "lowmemorykiller_stats.h"

static u32 lowmem_debug_level = 1;
static short lowmem_adj[6] = {
@@ -72,6 +73,7 @@ static unsigned long lowmem_deathpending_timeout;
static unsigned long lowmem_count(struct shrinker *s,
struct shrink_control *sc)
{
+ lmk_inc_stats(LMK_COUNT);
return global_node_page_state(NR_ACTIVE_ANON) +
global_node_page_state(NR_ACTIVE_FILE) +
global_node_page_state(NR_INACTIVE_ANON) +
@@ -95,6 +97,7 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
global_node_page_state(NR_SHMEM) -
total_swapcache_pages();

+ lmk_inc_stats(LMK_SCAN);
if (lowmem_adj_size < array_size)
array_size = lowmem_adj_size;
if (lowmem_minfree_size < array_size)
@@ -134,6 +137,7 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
if (task_lmk_waiting(p) &&
time_before_eq(jiffies, lowmem_deathpending_timeout)) {
task_unlock(p);
+ lmk_inc_stats(LMK_TIMEOUT);
rcu_read_unlock();
return 0;
}
@@ -179,7 +183,9 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
other_free * (long)(PAGE_SIZE / 1024));
lowmem_deathpending_timeout = jiffies + HZ;
rem += selected_tasksize;
- }
+ lmk_inc_stats(LMK_KILL);
+ } else
+ lmk_inc_stats(LMK_WASTE);

lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
sc->nr_to_scan, sc->gfp_mask, rem);
@@ -196,6 +202,7 @@ static struct shrinker lowmem_shrinker = {
static int __init lowmem_init(void)
{
register_shrinker(&lowmem_shrinker);
+ init_procfs_lmk();
return 0;
}
device_initcall(lowmem_init);
diff --git a/drivers/staging/android/lowmemorykiller_stats.c b/drivers/staging/android/lowmemorykiller_stats.c
new file mode 100644
index 0000000..673691c
--- /dev/null
+++ b/drivers/staging/android/lowmemorykiller_stats.c
@@ -0,0 +1,85 @@
+/*
+ * lowmemorykiller_stats
+ *
+ * Copyright (C) 2017 Sony Mobile Communications Inc.
+ *
+ * Author: Peter Enderborg <peter.enderborg@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+/* This code is bookkeeping of statistical information
+ * from lowmemorykiller and provide a node in proc "/proc/lmkstats".
+ */
+
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "lowmemorykiller_stats.h"
+
+struct lmk_stats {
+ atomic_long_t scans; /* counter as in shrinker scans */
+ atomic_long_t kills; /* the number of sigkills sent */
+ atomic_long_t waste; /* the numer of extensive calls that did
+ * not lead to anything
+ */
+ atomic_long_t timeout; /* counter for shrinker calls that needed
+ * to be cancelled due to pending kills
+ */
+ atomic_long_t count; /* number of shrinker count calls */
+ atomic_long_t unknown; /* internal */
+} st;
+
+void lmk_inc_stats(int key)
+{
+ switch (key) {
+ case LMK_SCAN:
+ atomic_long_inc(&st.scans);
+ break;
+ case LMK_KILL:
+ atomic_long_inc(&st.kills);
+ break;
+ case LMK_WASTE:
+ atomic_long_inc(&st.waste);
+ break;
+ case LMK_TIMEOUT:
+ atomic_long_inc(&st.timeout);
+ break;
+ case LMK_COUNT:
+ atomic_long_inc(&st.count);
+ break;
+ default:
+ atomic_long_inc(&st.unknown);
+ break;
+ }
+}
+
+static int lmk_proc_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "kill: %ld\n", atomic_long_read(&st.kills));
+ seq_printf(m, "scan: %ld\n", atomic_long_read(&st.scans));
+ seq_printf(m, "waste: %ld\n", atomic_long_read(&st.waste));
+ seq_printf(m, "timeout: %ld\n", atomic_long_read(&st.timeout));
+ seq_printf(m, "count: %ld\n", atomic_long_read(&st.count));
+ seq_printf(m, "unknown: %ld (internal)\n",
+ atomic_long_read(&st.unknown));
+
+ return 0;
+}
+
+static int lmk_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, lmk_proc_show, PDE_DATA(inode));
+}
+
+static const struct file_operations lmk_proc_fops = {
+ .open = lmk_proc_open,
+ .read = seq_read,
+ .release = single_release
+};
+
+int __init init_procfs_lmk(void)
+{
+ proc_create_data(LMK_PROCFS_NAME, 0444, NULL, &lmk_proc_fops, NULL);
+ return 0;
+}
diff --git a/drivers/staging/android/lowmemorykiller_stats.h b/drivers/staging/android/lowmemorykiller_stats.h
new file mode 100644
index 0000000..abeb6924
--- /dev/null
+++ b/drivers/staging/android/lowmemorykiller_stats.h
@@ -0,0 +1,29 @@
+/*
+ * lowmemorykiller_stats interface
+ *
+ * Copyright (C) 2017 Sony Mobile Communications Inc.
+ *
+ * Author: Peter Enderborg <peter.enderborg@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+enum lmk_kill_stats {
+ LMK_SCAN = 1,
+ LMK_KILL = 2,
+ LMK_WASTE = 3,
+ LMK_TIMEOUT = 4,
+ LMK_COUNT = 5
+};
+
+#define LMK_PROCFS_NAME "lmkstats"
+
+#ifdef CONFIG_ANDROID_LOW_MEMORY_KILLER_STATS
+void lmk_inc_stats(int key);
+int __init init_procfs_lmk(void);
+#else
+static inline void lmk_inc_stats(int key) { return; };
+static inline int __init init_procfs_lmk(void) { return 0; };
+#endif
--
2.4.2