Merge "ANDROID: Avoid taking multiple locks in handle_lmk_event" (409330d3) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/staging/android/lowmemorykiller.c

+17 −12

Original line number	Diff line number	Diff line
		@@ -127,6 +127,7 @@ void handle_lmk_event(struct task_struct *selected, short min_score_adj)
		struct lmk_event *event;
		int res;
		long rss_in_pages = -1;
		char taskname[MAX_TASKNAME];
		struct mm_struct *mm = get_task_mm(selected);

		if (mm) {
		@@ -134,6 +135,17 @@ void handle_lmk_event(struct task_struct *selected, short min_score_adj)
		mmput(mm);
		}

		res = get_cmdline(selected, taskname, MAX_TASKNAME - 1);

		/* No valid process name means this is definitely not associated with a
		* userspace activity.
		*/

		if (res <= 0 \|\| res >= MAX_TASKNAME)
		return;

		taskname[res] = '\0';

		spin_lock(&lmk_event_lock);

		head = event_buffer.head;
		@@ -148,18 +160,8 @@ void handle_lmk_event(struct task_struct *selected, short min_score_adj)
		events = (struct lmk_event *) event_buffer.buf;
		event = &events[head];

		res = get_cmdline(selected, event->taskname, MAX_TASKNAME - 1);
		memcpy(event->taskname, taskname, res + 1);

		/* No valid process name means this is definitely not associated with a
		* userspace activity.
		*/

		if (res <= 0 \|\| res >= MAX_TASKNAME) {
		spin_unlock(&lmk_event_lock);
		return;
		}

		event->taskname[res] = '\0';
		event->pid = selected->pid;
		event->uid = from_kuid_munged(current_user_ns(), task_uid(selected));
		if (selected->group_leader)
		@@ -785,7 +787,6 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)

		lowmem_deathpending_timeout = jiffies + HZ;
		rem += selected_tasksize;
		handle_lmk_event(selected, min_score_adj);
		rcu_read_unlock();
		/* give the system time to free up the memory */
		msleep_interruptible(20);
		@@ -800,6 +801,10 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
		sc->nr_to_scan, sc->gfp_mask, rem);
		mutex_unlock(&scan_mutex);

		if (selected)
		handle_lmk_event(selected, min_score_adj);

		return rem;
		}