Merge "lowmemorykiller: fix scan_mutex contention" (93de5f5d) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/staging/android/lowmemorykiller.c

+28 −3

Original line number	Diff line number	Diff line
		@@ -211,6 +211,22 @@ static int test_task_flag(struct task_struct *p, int flag)
		return 0;
		}

		static int test_task_state(struct task_struct *p, int state)
		{
		struct task_struct *t;

		for_each_thread(p, t) {
		task_lock(t);
		if (t->state & state) {
		task_unlock(t);
		return 1;
		}
		task_unlock(t);
		}

		return 0;
		}

		static DEFINE_MUTEX(scan_mutex);

		int can_use_cma_pages(gfp_t gfp_mask)
		@@ -398,7 +414,7 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		int other_free;
		int other_file;

		if (mutex_lock_interruptible(&scan_mutex) < 0)
		if (!mutex_trylock(&scan_mutex))
		return 0;

		other_free = global_page_state(NR_FREE_PAGES);
		@@ -457,8 +473,6 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		if (time_before_eq(jiffies, lowmem_deathpending_timeout)) {
		if (test_task_flag(tsk, TIF_MEMDIE)) {
		rcu_read_unlock();
		/* give the system time to free up the memory */
		msleep_interruptible(20);
		mutex_unlock(&scan_mutex);
		return 0;
		}
		@@ -495,6 +509,17 @@ static unsigned long lowmem_scan(struct shrinker s, struct shrink_control sc)
		long cache_limit = minfree * (long)(PAGE_SIZE / 1024);
		long free = other_free * (long)(PAGE_SIZE / 1024);
		trace_lowmemory_kill(selected, cache_size, cache_limit, free);

		if (test_task_flag(selected, TIF_MEMDIE) &&
		(test_task_state(selected, TASK_UNINTERRUPTIBLE))) {
		lowmem_print(2, "'%s' (%d) is already killed\n",
		selected->comm,
		selected->pid);
		rcu_read_unlock();
		mutex_unlock(&scan_mutex);
		return 0;
		}

		lowmem_print(1, "Killing '%s' (%d), adj %hd,\n" \
		" to free %ldkB on behalf of '%s' (%d) because\n" \
		" cache %ldkB is below limit %ldkB for oom_score_adj %hd\n" \