Merge "mm: oom_kill: Support further prioritization of OOM kills" (7b082008) · Commits · e / devices / android_kernel_fairphone_FP5

include/linux/oom.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,9 @@ struct oom_control {
		unsigned long totalpages;
		struct task_struct *chosen;
		unsigned long chosen_points;
		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		short min_kill_adj;
		#endif

		/* Used to print the constraint info. */
		enum oom_constraint constraint;

mm/Kconfig

+27 −0

Original line number	Diff line number	Diff line
		@@ -804,4 +804,31 @@ config ARCH_HAS_PTE_SPECIAL
		config ARCH_HAS_HUGEPD
		bool

		config PRIORITIZE_OOM_TASKS
		bool "Attempt to further prioritize OOM killer kills"
		depends on QGKI
		help
		When the OOM killer selects a task to kill it considers all tasks
		with a oom_score_adj value > OOM_SCORE_ADJ_MIN. This doesn't work
		well when the OS has 'high priority' tasks which should only be
		considered for killing after all other 'lower priority' tasks
		have first been killed.

		Enable this option to impose a limit on the minimum task
		oom_score_adj which should first be considered for killing
		before allowing the OOM killer to select tasks without
		limitation.

		If unsure, say N.

		config OOM_TASK_PRIORITY_ADJ_LIMIT
		int "Min oom_score_adj when priotizing OOM killer kills"
		depends on PRIORITIZE_OOM_TASKS
		range -1000 1000
		default 0
		help
		With this parameter you can limit the OOM killer to first kill
		tasks with an oom_score_adj value above a certain threshold
		before considering tasks with a lower oom_score_adj value.

		endmenu

mm/oom_kill.c

+51 −10

Original line number	Diff line number	Diff line
		@@ -317,6 +317,10 @@ static int oom_evaluate_task(struct task_struct task, void arg)
		{
		struct oom_control *oc = arg;
		unsigned long points;
		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		struct task_struct *p;
		short adj;
		#endif

		if (oom_unkillable_task(task))
		goto next;
		@@ -337,6 +341,18 @@ static int oom_evaluate_task(struct task_struct task, void arg)
		goto abort;
		}

		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		p = find_lock_task_mm(task);
		if (!p)
		goto next;

		adj = p->signal->oom_score_adj;
		task_unlock(p);

		if (adj < oc->min_kill_adj)
		goto next;
		#endif

		/*
		* If task is allocating a lot of memory and has been marked to be
		* killed first if it triggers an oom, then select it.
		@@ -994,7 +1010,11 @@ static void oom_kill_process(struct oom_control oc, const char message)
		}
		task_unlock(victim);

		if (__ratelimit(&oom_rs))
		if (__ratelimit(&oom_rs)
		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		&& oc->min_kill_adj < CONFIG_OOM_TASK_PRIORITY_ADJ_LIMIT
		#endif
		)
		dump_header(oc, victim);

		/*
		@@ -1070,13 +1090,9 @@ bool out_of_memory(struct oom_control *oc)

		if (oom_killer_disabled)
		return false;

		if (try_online_one_block(numa_node_id())) {
		/* Got some memory back */
		WARN(1, "OOM killer had to online a memory block\n");
		return true;
		}

		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		oc->min_kill_adj = OOM_SCORE_ADJ_MIN;
		#endif
		if (!is_memcg_oom(oc)) {
		blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
		if (freed > 0)
		@@ -1112,19 +1128,44 @@ bool out_of_memory(struct oom_control *oc)
		oc->constraint = constrained_alloc(oc);
		if (oc->constraint != CONSTRAINT_MEMORY_POLICY)
		oc->nodemask = NULL;
		check_panic_on_oom(oc);

		if (!is_memcg_oom(oc) && sysctl_oom_kill_allocating_task &&
		current->mm && !oom_unkillable_task(current) &&
		oom_cpuset_eligible(current, oc) &&
		current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
		check_panic_on_oom(oc);
		get_task_struct(current);
		oc->chosen = current;
		oom_kill_process(oc, "Out of memory (oom_kill_allocating_task)");
		return true;
		}

		#ifdef CONFIG_PRIORITIZE_OOM_TASKS
		if (oc->min_kill_adj < CONFIG_OOM_TASK_PRIORITY_ADJ_LIMIT) {
		short prev_min_kill_adj = oc->min_kill_adj;

		oc->min_kill_adj = CONFIG_OOM_TASK_PRIORITY_ADJ_LIMIT;
		select_bad_process(oc);
		if (!oc->chosen) {
		pr_warn_ratelimited("Could not find task with adj >= %d\n",
		CONFIG_OOM_TASK_PRIORITY_ADJ_LIMIT);
		oc->min_kill_adj = prev_min_kill_adj;
		oc->chosen_points = 0;
		}

		}
		#endif

		if (!oc->chosen) {
		if (try_online_one_block(numa_node_id())) {
		/* Got some memory back */
		WARN(1, "OOM killer had to online a memory block\n");
		return true;
		}
		check_panic_on_oom(oc);
		select_bad_process(oc);
		}

		/* Found nothing?!?! */
		if (!oc->chosen) {
		dump_header(oc, NULL);