Merge "lowmemorykiller: sysfs node and notifications" (9c0dc3d9) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/staging/android/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,17 @@ config ANDROID_VSOC
		a 'cuttlefish' Android image inside QEmu. The driver interacts with
		a QEmu ivshmem device. If built as a module, it will be called vsoc.

		config ANDROID_LMK_NOTIFY_TRIGGER
		bool "Android Low Memory Killer Notify Trigger"
		depends on ANDROID_LOW_MEMORY_KILLER
		default n
		---help---
		Create node "/sys/kernel/mm/lowmemkiller/notify_trigger_active",
		on which an userspace application can poll for notification when
		the number of free physical memory pages in the system falls below
		a set threshold. The threshold is set by the new module parameter
		"/sys/module/lowmemorykiller/parameters/notify_trigger".

		source "drivers/staging/android/ion/Kconfig"

		endif # if ANDROID

drivers/staging/android/lowmemorykiller.c

+110 −1

Original line number	Diff line number	Diff line
		@@ -92,6 +92,12 @@ static int lmk_fast_run = 1;

		static unsigned long lowmem_deathpending_timeout;

		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		static struct shrink_control lowmem_notif_sc = {GFP_KERNEL, 0};
		static int lowmem_minfree_notif_trigger;
		static struct kobject *lowmem_notify_kobj;
		#endif

		#define lowmem_print(level, x...) \
		do { \
		if (lowmem_debug_level >= (level)) \
		@@ -582,6 +588,34 @@ static void mark_lmk_victim(struct task_struct *tsk)
		}
		}

		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		static void lowmem_notify_killzone_approach(void);

		static int get_free_ram(int other_free, int other_file,
		struct shrink_control *sc)
		{
		*other_free = global_page_state(NR_FREE_PAGES) - totalreserve_pages;

		if (global_node_page_state(NR_SHMEM) + total_swapcache_pages() +
		global_node_page_state(NR_UNEVICTABLE) <
		global_node_page_state(NR_FILE_PAGES))
		*other_file = global_node_page_state(NR_FILE_PAGES) -
		global_node_page_state(NR_SHMEM) -
		global_node_page_state(NR_UNEVICTABLE) -
		total_swapcache_pages();
		else
		*other_file = 0;

		tune_lmk_param(other_free, other_file, sc);

		if (*other_free < lowmem_minfree_notif_trigger &&
		*other_file < lowmem_minfree_notif_trigger)
		return 1;
		else
		return 0;
		}
		#endif

		static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		{
		struct task_struct *tsk;
		@@ -601,6 +635,12 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		if (!mutex_trylock(&scan_mutex))
		return 0;

		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		lowmem_notif_sc.gfp_mask = sc->gfp_mask;

		if (get_free_ram(&other_free, &other_file, sc))
		lowmem_notify_killzone_approach();
		#else
		other_free = global_page_state(NR_FREE_PAGES) - totalreserve_pages;

		if (global_node_page_state(NR_SHMEM) + total_swapcache_pages() +
		@@ -614,6 +654,7 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		other_file = 0;

		tune_lmk_param(&other_free, &other_file, sc);
		#endif

		if (lowmem_adj_size < array_size)
		array_size = lowmem_adj_size;
		@@ -801,8 +842,74 @@ static struct shrinker lowmem_shrinker = {
		.seeks = DEFAULT_SEEKS * 16
		};

		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		static void lowmem_notify_killzone_approach(void)
		{
		lowmem_print(3, "notification trigger activated\n");
		sysfs_notify(lowmem_notify_kobj, NULL,
		"notify_trigger_active");
		}

		static ssize_t lowmem_notify_trigger_active_show(struct kobject *k,
		struct kobj_attribute *attr,
		char *buf)
		{
		int other_free, other_file;

		if (get_free_ram(&other_free, &other_file, &lowmem_notif_sc))
		return snprintf(buf, 3, "1\n");
		else
		return snprintf(buf, 3, "0\n");
		}

		static struct kobj_attribute lowmem_notify_trigger_active_attr =
		__ATTR(notify_trigger_active, 0444,
		lowmem_notify_trigger_active_show, NULL);

		static struct attribute *lowmem_notify_default_attrs[] = {
		&lowmem_notify_trigger_active_attr.attr, NULL,
		};

		static ssize_t lowmem_show(struct kobject k, struct attribute attr, char *buf)
		{
		struct kobj_attribute *kobj_attr;

		kobj_attr = container_of(attr, struct kobj_attribute, attr);
		return kobj_attr->show(k, kobj_attr, buf);
		}

		static const struct sysfs_ops lowmem_notify_ops = {
		.show = lowmem_show,
		};

		static void lowmem_notify_kobj_release(struct kobject *kobj)
		{
		/* Nothing to be done here */
		}

		static struct kobj_type lowmem_notify_kobj_type = {
		.release = lowmem_notify_kobj_release,
		.sysfs_ops = &lowmem_notify_ops,
		.default_attrs = lowmem_notify_default_attrs,
		};
		#endif

		static int __init lowmem_init(void)
		{
		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		int rc;

		lowmem_notify_kobj = kzalloc(sizeof(*lowmem_notify_kobj), GFP_KERNEL);
		if (!lowmem_notify_kobj)
		return -ENOMEM;

		rc = kobject_init_and_add(lowmem_notify_kobj, &lowmem_notify_kobj_type,
		mm_kobj, "lowmemkiller");
		if (rc) {
		kfree(lowmem_notify_kobj);
		return rc;
		}
		#endif
		register_shrinker(&lowmem_shrinker);
		vmpressure_notifier_register(&lmk_vmpr_nb);
		lmk_event_init();
		@@ -904,4 +1011,6 @@ 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);
		module_param_named(lmk_fast_run, lmk_fast_run, int, S_IRUGO \| S_IWUSR);

		#ifdef CONFIG_ANDROID_LMK_NOTIFY_TRIGGER
		module_param_named(notify_trigger, lowmem_minfree_notif_trigger, uint, 0644);
		#endif