Merge "sched: Prevent race conditions where upmigrate_min_nice changes" (44dd0219) · Commits · e / devices / android_kernel_sony_msm8994

kernel/sched/fair.c

+37 −15

Original line number	Diff line number	Diff line
		@@ -1324,6 +1324,7 @@ unsigned int __read_mostly sysctl_sched_downmigrate_pct = 60;
		* Tasks whose nice value is > sysctl_sched_upmigrate_min_nice are never
		* considered as "big" tasks.
		*/
		static int __read_mostly sched_upmigrate_min_nice = 15;
		int __read_mostly sysctl_sched_upmigrate_min_nice = 15;

		/*
		@@ -1374,6 +1375,8 @@ void set_hmp_defaults(void)
		sched_init_task_load_windows =
		div64_u64((u64)sysctl_sched_init_task_load_pct *
		(u64)sched_ravg_window, 100);

		sched_upmigrate_min_nice = sysctl_sched_upmigrate_min_nice;
		}

		u32 sched_get_init_task_load(struct task_struct *p)
		@@ -1470,7 +1473,7 @@ static inline int is_big_task(struct task_struct *p)
		int nice = TASK_NICE(p);

		/* Todo: Provide cgroup-based control as well? */
		if (nice > sysctl_sched_upmigrate_min_nice)
		if (nice > sched_upmigrate_min_nice)
		return 0;

		load = scale_load_to_cpu(load, task_cpu(p));
		@@ -1658,7 +1661,7 @@ static int task_will_fit(struct task_struct *p, int cpu)
		return 1;
		} else {
		/* Todo: Provide cgroup-based control as well? */
		if (nice > sysctl_sched_upmigrate_min_nice)
		if (nice > sched_upmigrate_min_nice)
		return 1;

		load = scale_load_to_cpu(task_load(p), cpu);
		@@ -2197,11 +2200,16 @@ int sched_hmp_proc_update_handler(struct ctl_table *table, int write,
		int ret;
		unsigned int data = (unsigned int )table->data;
		unsigned int old_val = *data;
		int update_min_nice = 0;

		ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);

		if (ret \|\| !write \|\| !sched_enable_hmp)
		return ret;

		if (write && (old_val == *data))
		return 0;

		if (data == &sysctl_sched_min_runtime) {
		sched_min_runtime = ((u64) sysctl_sched_min_runtime) * 1000;
		return 0;
		@@ -2212,6 +2220,23 @@ int sched_hmp_proc_update_handler(struct ctl_table *table, int write,
		return -EINVAL;
		}

		if (data == (unsigned int *)&sysctl_sched_upmigrate_min_nice)
		update_min_nice = 1;

		if (update_min_nice) {
		if (((int )data) < -20 \|\| ((int )data) > 19) {
		*data = old_val;
		return -EINVAL;
		}
		} else {
		/* all tunables other than min_nice are in percentage */
		if (sysctl_sched_downmigrate_pct >
		sysctl_sched_upmigrate_pct \|\| *data > 100) {
		*data = old_val;
		return -EINVAL;
		}
		}

		/*
		* Big/Small task tunable change will need to re-classify tasks on
		* runqueue as big and small and set their counters appropriately.
		@@ -2220,18 +2245,16 @@ int sched_hmp_proc_update_handler(struct ctl_table *table, int write,
		* includes taking runqueue lock of all online cpus and re-initiatizing
		* their big/small counter values based on changed criteria.
		*/
		if ((*data != old_val) &&
		(data == &sysctl_sched_upmigrate_pct \|\|
		data == &sysctl_sched_small_task_pct)) {
		if ((data == &sysctl_sched_upmigrate_pct \|\|
		data == &sysctl_sched_small_task_pct \|\| update_min_nice)) {
		get_online_cpus();
		pre_big_small_task_count_change(cpu_online_mask);
		}

		set_hmp_defaults();

		if ((*data != old_val) &&
		(data == &sysctl_sched_upmigrate_pct \|\|
		data == &sysctl_sched_small_task_pct)) {
		if ((data == &sysctl_sched_upmigrate_pct \|\|
		data == &sysctl_sched_small_task_pct \|\| update_min_nice)) {
		post_big_small_task_count_change(cpu_online_mask);
		put_online_cpus();
		}
		@@ -2346,8 +2369,7 @@ static inline int migration_needed(struct rq rq, struct task_struct p)
		return 0;

		/* Todo: cgroup-based control? */
		if (nice > sysctl_sched_upmigrate_min_nice &&
		rq->capacity > min_capacity)
		if (nice > sched_upmigrate_min_nice && rq->capacity > min_capacity)
		return MOVE_TO_LITTLE_CPU;

		if (!task_will_fit(p, cpu_of(rq)))

kernel/sysctl.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -414,7 +414,7 @@ static struct ctl_table kern_table[] = {
		.data = &sysctl_sched_upmigrate_min_nice,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = proc_dointvec,
		.proc_handler = sched_hmp_proc_update_handler,
		},
		{
		.procname = "sched_prefer_idle",