android-tracking.patch

Minimal set of kernel changes to support Android operation.
Note arch/arm/configs/gta02-android-defconfig

3 files changed, 125 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 9494400e8fd..e07ea1cec56 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -391,6 +391,11 @@ config THINKPAD_ACPI_HOTKEY_POLL
 	  If you are not sure, say Y here.  The driver enables polling only if
 	  it is strictly necessary to do so.
 
+config LOW_MEMORY_KILLER
+    tristate "Low Memory Killer"
+	  ---help---
+	  Register processes to be killed when memory is low.
+
 config ATMEL_SSC
 	tristate "Device driver for Atmel SSC peripheral"
 	depends on AVR32 || ARCH_AT91
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 909e2468cdc..8455289665b 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -31,3 +31,4 @@ obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
 obj-$(CONFIG_SGI_XP)		+= sgi-xp/
 obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
 obj-$(CONFIG_HP_ILO)		+= hpilo.o
+obj-$(CONFIG_LOW_MEMORY_KILLER)	+= lowmemorykiller.o
diff --git a/drivers/misc/lowmemorykiller.c b/drivers/misc/lowmemorykiller.c
new file mode 100644
index 00000000000..3715d56ca96
--- /dev/null
+++ b/drivers/misc/lowmemorykiller.c
@@ -0,0 +1,119 @@
+/* drivers/misc/lowmemorykiller.c
+ *
+ * Copyright (C) 2007-2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/oom.h>
+#include <linux/sched.h>
+
+static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask);
+
+static struct shrinker lowmem_shrinker = {
+	.shrink = lowmem_shrink,
+	.seeks = DEFAULT_SEEKS * 16
+};
+static uint32_t lowmem_debug_level = 2;
+static int lowmem_adj[6] = {
+	0,
+	1,
+	6,
+	12,
+};
+static int lowmem_adj_size = 4;
+static size_t lowmem_minfree[6] = {
+	3*512, // 6MB
+	2*1024, // 8MB
+	4*1024, // 16MB
+	16*1024, // 64MB
+};
+static int lowmem_minfree_size = 4;
+
+#define lowmem_print(level, x...) do { if(lowmem_debug_level >= (level)) printk(x); } while(0)
+
+module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR);
+module_param_array_named(adj, lowmem_adj, int, &lowmem_adj_size, S_IRUGO | S_IWUSR);
+module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size, S_IRUGO | S_IWUSR);
+module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR);
+
+static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask)
+{
+	struct task_struct *p;
+	struct task_struct *selected = NULL;
+	int rem = 0;
+	int tasksize;
+	int i;
+	int min_adj = OOM_ADJUST_MAX + 1;
+	int selected_tasksize = 0;
+	int array_size = ARRAY_SIZE(lowmem_adj);
+	int other_free = global_page_state(NR_FREE_PAGES) + global_page_state(NR_FILE_PAGES);
+	if(lowmem_adj_size < array_size)
+		array_size = lowmem_adj_size;
+	if(lowmem_minfree_size < array_size)
+		array_size = lowmem_minfree_size;
+	for(i = 0; i < array_size; i++) {
+		if(other_free < lowmem_minfree[i]) {
+			min_adj = lowmem_adj[i];
+			break;
+		}
+	}
+	if(nr_to_scan > 0)
+		lowmem_print(3, "lowmem_shrink %d, %x, ofree %d, ma %d\n", nr_to_scan, gfp_mask, other_free, min_adj);
+	read_lock(&tasklist_lock);
+	for_each_process(p) {
+		if(p->oomkilladj >= 0 && p->mm) {
+			tasksize = get_mm_rss(p->mm);
+			if(nr_to_scan > 0 && tasksize > 0 && p->oomkilladj >= min_adj) {
+				if(selected == NULL ||
+				   p->oomkilladj > selected->oomkilladj ||
+				   (p->oomkilladj == selected->oomkilladj &&
+				    tasksize > selected_tasksize)) {
+					selected = p;
+					selected_tasksize = tasksize;
+					lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n",
+					             p->pid, p->comm, p->oomkilladj, tasksize);
+				}
+			}
+			rem += tasksize;
+		}
+	}
+	if(selected != NULL) {
+		lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d\n",
+		             selected->pid, selected->comm,
+		             selected->oomkilladj, selected_tasksize);
+		force_sig(SIGKILL, selected);
+		rem -= selected_tasksize;
+	}
+	lowmem_print(4, "lowmem_shrink %d, %x, return %d\n", nr_to_scan, gfp_mask, rem);
+	read_unlock(&tasklist_lock);
+	return rem;
+}
+
+static int __init lowmem_init(void)
+{
+	register_shrinker(&lowmem_shrinker);
+	return 0;
+}
+
+static void __exit lowmem_exit(void)
+{
+	unregister_shrinker(&lowmem_shrinker);
+}
+
+module_init(lowmem_init);
+module_exit(lowmem_exit);
+
+MODULE_LICENSE("GPL");
+