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Commit 69f60905 authored by Jin Qian's avatar Jin Qian
Browse files

uid_sys_stats: defer io stats calulation for dead tasks 



Store sum of dead task io stats in uid_entry and defer uid io
calulation until next uid proc stat change or dumpsys.

Bug: 37754877
Change-Id: I970f010a4c841c5ca26d0efc7e027414c3c952e0
Signed-off-by: default avatarJin Qian <jinqian@google.com>
parent 1607c0b6

drivers/misc/uid_sys_stats.c

+42 −65
Original line number Diff line number Diff line
@@ -49,7 +49,8 @@ struct io_stats { 


#define UID_STATE_TOTAL_CURR	2

#define UID_STATE_TOTAL_LAST	3

#define UID_STATE_SIZE		4

#define UID_STATE_DEAD_TASKS	4

#define UID_STATE_SIZE		5



struct uid_entry {

	uid_t uid;
@@ -226,35 +227,44 @@ static u64 compute_write_bytes(struct task_struct *task) 
	return task->ioac.write_bytes - task->ioac.cancelled_write_bytes;

}



static void add_uid_io_curr_stats(struct uid_entry *uid_entry,

			struct task_struct *task)

static void add_uid_io_stats(struct uid_entry *uid_entry,

			struct task_struct *task, int slot)

{

	struct io_stats *io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];

	struct io_stats *io_slot = &uid_entry->io[slot];



	io_curr->read_bytes += task->ioac.read_bytes;

	io_curr->write_bytes += compute_write_bytes(task);

	io_curr->rchar += task->ioac.rchar;

	io_curr->wchar += task->ioac.wchar;

	io_curr->fsync += task->ioac.syscfs;

	io_slot->read_bytes += task->ioac.read_bytes;

	io_slot->write_bytes += compute_write_bytes(task);

	io_slot->rchar += task->ioac.rchar;

	io_slot->wchar += task->ioac.wchar;

	io_slot->fsync += task->ioac.syscfs;

}



static void clean_uid_io_last_stats(struct uid_entry *uid_entry,

			struct task_struct *task)

static void compute_uid_io_bucket_stats(struct io_stats *io_bucket,

					struct io_stats *io_curr,

					struct io_stats *io_last,

					struct io_stats *io_dead)

{

	struct io_stats *io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

	io_bucket->read_bytes += io_curr->read_bytes + io_dead->read_bytes -

		io_last->read_bytes;

	io_bucket->write_bytes += io_curr->write_bytes + io_dead->write_bytes -

		io_last->write_bytes;

	io_bucket->rchar += io_curr->rchar + io_dead->rchar - io_last->rchar;

	io_bucket->wchar += io_curr->wchar + io_dead->wchar - io_last->wchar;

	io_bucket->fsync += io_curr->fsync + io_dead->fsync - io_last->fsync;



	io_last->read_bytes -= task->ioac.read_bytes;

	io_last->write_bytes -= compute_write_bytes(task);

	io_last->rchar -= task->ioac.rchar;

	io_last->wchar -= task->ioac.wchar;

	io_last->fsync -= task->ioac.syscfs;

	io_last->read_bytes = io_curr->read_bytes;

	io_last->write_bytes = io_curr->write_bytes;

	io_last->rchar = io_curr->rchar;

	io_last->wchar = io_curr->wchar;

	io_last->fsync = io_curr->fsync;



	memset(io_dead, 0, sizeof(struct io_stats));

}



static void update_io_stats_all_locked(void)

{

	struct uid_entry *uid_entry;

	struct task_struct *task, *temp;

	struct io_stats *io_bucket, *io_curr, *io_last;

	struct user_namespace *user_ns = current_user_ns();

	unsigned long bkt;

	uid_t uid;
@@ -269,70 +279,38 @@ static void update_io_stats_all_locked(void) 
		uid_entry = find_or_register_uid(uid);

		if (!uid_entry)

			continue;

		add_uid_io_curr_stats(uid_entry, task);

		add_uid_io_stats(uid_entry, task, UID_STATE_TOTAL_CURR);

	} while_each_thread(temp, task);

	rcu_read_unlock();



	hash_for_each(hash_table, bkt, uid_entry, hash) {

		io_bucket = &uid_entry->io[uid_entry->state];

		io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];

		io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];



		io_bucket->read_bytes +=

			io_curr->read_bytes - io_last->read_bytes;

		io_bucket->write_bytes +=

			io_curr->write_bytes - io_last->write_bytes;

		io_bucket->rchar += io_curr->rchar - io_last->rchar;

		io_bucket->wchar += io_curr->wchar - io_last->wchar;

		io_bucket->fsync += io_curr->fsync - io_last->fsync;



		io_last->read_bytes = io_curr->read_bytes;

		io_last->write_bytes = io_curr->write_bytes;

		io_last->rchar = io_curr->rchar;

		io_last->wchar = io_curr->wchar;

		io_last->fsync = io_curr->fsync;

		compute_uid_io_bucket_stats(&uid_entry->io[uid_entry->state],

					&uid_entry->io[UID_STATE_TOTAL_CURR],

					&uid_entry->io[UID_STATE_TOTAL_LAST],

					&uid_entry->io[UID_STATE_DEAD_TASKS]);

	}

}



static void update_io_stats_uid_locked(uid_t target_uid)

static void update_io_stats_uid_locked(struct uid_entry *uid_entry)

{

	struct uid_entry *uid_entry;

	struct task_struct *task, *temp;

	struct io_stats *io_bucket, *io_curr, *io_last;

	struct user_namespace *user_ns = current_user_ns();



	uid_entry = find_or_register_uid(target_uid);

	if (!uid_entry)

		return;



	memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,

		sizeof(struct io_stats));



	rcu_read_lock();

	do_each_thread(temp, task) {

		if (from_kuid_munged(user_ns, task_uid(task)) != target_uid)

		if (from_kuid_munged(user_ns, task_uid(task)) != uid_entry->uid)

			continue;

		add_uid_io_curr_stats(uid_entry, task);

		add_uid_io_stats(uid_entry, task, UID_STATE_TOTAL_CURR);

	} while_each_thread(temp, task);

	rcu_read_unlock();



	io_bucket = &uid_entry->io[uid_entry->state];

	io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];

	io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];



	io_bucket->read_bytes +=

		io_curr->read_bytes - io_last->read_bytes;

	io_bucket->write_bytes +=

		io_curr->write_bytes - io_last->write_bytes;

	io_bucket->rchar += io_curr->rchar - io_last->rchar;

	io_bucket->wchar += io_curr->wchar - io_last->wchar;

	io_bucket->fsync += io_curr->fsync - io_last->fsync;



	io_last->read_bytes = io_curr->read_bytes;

	io_last->write_bytes = io_curr->write_bytes;

	io_last->rchar = io_curr->rchar;

	io_last->wchar = io_curr->wchar;

	io_last->fsync = io_curr->fsync;

	compute_uid_io_bucket_stats(&uid_entry->io[uid_entry->state],

				&uid_entry->io[UID_STATE_TOTAL_CURR],

				&uid_entry->io[UID_STATE_TOTAL_LAST],

				&uid_entry->io[UID_STATE_DEAD_TASKS]);

}



static int uid_io_show(struct seq_file *m, void *v)
@@ -417,7 +395,7 @@ static ssize_t uid_procstat_write(struct file *file, 
		return count;

	}



	update_io_stats_uid_locked(uid);

	update_io_stats_uid_locked(uid_entry);



	uid_entry->state = state;
@@ -457,8 +435,7 @@ static int process_notifier(struct notifier_block *self, 
	uid_entry->power += task->cpu_power;

	task->cpu_power = ULLONG_MAX;



	update_io_stats_uid_locked(uid);

	clean_uid_io_last_stats(uid_entry, task);

	add_uid_io_stats(uid_entry, task, UID_STATE_DEAD_TASKS);



exit:

	rt_mutex_unlock(&uid_lock);