Commit 7cf2b0f9 authored by Dave Chinner's avatar Dave Chinner Committed by Darrick J. Wong
Browse files

xfs: bound maximum wait time for inodegc work 



Currently inodegc work can sit queued on the per-cpu queue until
the workqueue is either flushed of the queue reaches a depth that
triggers work queuing (and later throttling). This means that we
could queue work that waits for a long time for some other event to
trigger flushing.

Hence instead of just queueing work at a specific depth, use a
delayed work that queues the work at a bound time. We can still
schedule the work immediately at a given depth, but we no long need
to worry about leaving a number of items on the list that won't get
processed until external events prevail.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent e89ab76d

fs/xfs/xfs_icache.c

+22 −14
Original line number Diff line number Diff line
@@ -440,7 +440,7 @@ xfs_inodegc_queue_all( 
	for_each_online_cpu(cpu) {

		gc = per_cpu_ptr(mp->m_inodegc, cpu);

		if (!llist_empty(&gc->list))

			queue_work_on(cpu, mp->m_inodegc_wq, &gc->work);

			mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0);

	}

}
@@ -1841,8 +1841,8 @@ void 
xfs_inodegc_worker(

	struct work_struct	*work)

{

	struct xfs_inodegc	*gc = container_of(work, struct xfs_inodegc,

							work);

	struct xfs_inodegc	*gc = container_of(to_delayed_work(work),

						struct xfs_inodegc, work);

	struct llist_node	*node = llist_del_all(&gc->list);

	struct xfs_inode	*ip, *n;
@@ -2014,6 +2014,7 @@ xfs_inodegc_queue( 
	struct xfs_inodegc	*gc;

	int			items;

	unsigned int		shrinker_hits;

	unsigned long		queue_delay = 1;



	trace_xfs_inode_set_need_inactive(ip);

	spin_lock(&ip->i_flags_lock);
@@ -2025,19 +2026,26 @@ xfs_inodegc_queue( 
	items = READ_ONCE(gc->items);

	WRITE_ONCE(gc->items, items + 1);

	shrinker_hits = READ_ONCE(gc->shrinker_hits);

	put_cpu_ptr(gc);



	if (!xfs_is_inodegc_enabled(mp))

	/*

	 * We queue the work while holding the current CPU so that the work

	 * is scheduled to run on this CPU.

	 */

	if (!xfs_is_inodegc_enabled(mp)) {

		put_cpu_ptr(gc);

		return;

	}



	if (xfs_inodegc_want_queue_work(ip, items))

		queue_delay = 0;



	if (xfs_inodegc_want_queue_work(ip, items)) {

	trace_xfs_inodegc_queue(mp, __return_address);

		queue_work(mp->m_inodegc_wq, &gc->work);

	}

	mod_delayed_work(mp->m_inodegc_wq, &gc->work, queue_delay);

	put_cpu_ptr(gc);



	if (xfs_inodegc_want_flush_work(ip, items, shrinker_hits)) {

		trace_xfs_inodegc_throttle(mp, __return_address);

		flush_work(&gc->work);

		flush_delayed_work(&gc->work);

	}

}
@@ -2054,7 +2062,7 @@ xfs_inodegc_cpu_dead( 
	unsigned int		count = 0;



	dead_gc = per_cpu_ptr(mp->m_inodegc, dead_cpu);

	cancel_work_sync(&dead_gc->work);

	cancel_delayed_work_sync(&dead_gc->work);



	if (llist_empty(&dead_gc->list))

		return;
@@ -2073,12 +2081,12 @@ xfs_inodegc_cpu_dead( 
	llist_add_batch(first, last, &gc->list);

	count += READ_ONCE(gc->items);

	WRITE_ONCE(gc->items, count);

	put_cpu_ptr(gc);



	if (xfs_is_inodegc_enabled(mp)) {

		trace_xfs_inodegc_queue(mp, __return_address);

		queue_work(mp->m_inodegc_wq, &gc->work);

		mod_delayed_work(mp->m_inodegc_wq, &gc->work, 0);

	}

	put_cpu_ptr(gc);

}



/*
@@ -2173,7 +2181,7 @@ xfs_inodegc_shrinker_scan( 
			unsigned int	h = READ_ONCE(gc->shrinker_hits);



			WRITE_ONCE(gc->shrinker_hits, h + 1);

			queue_work_on(cpu, mp->m_inodegc_wq, &gc->work);

			mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0);

			no_items = false;

		}

	}

fs/xfs/xfs_mount.h

+1 −1
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ struct xfs_error_cfg { 
 */

struct xfs_inodegc {

	struct llist_head	list;

	struct work_struct	work;

	struct delayed_work	work;



	/* approximate count of inodes in the list */

	unsigned int		items;

fs/xfs/xfs_super.c

+1 −1
Original line number Diff line number Diff line
@@ -1074,7 +1074,7 @@ xfs_inodegc_init_percpu( 
		gc = per_cpu_ptr(mp->m_inodegc, cpu);

		init_llist_head(&gc->list);

		gc->items = 0;

		INIT_WORK(&gc->work, xfs_inodegc_worker);

		INIT_DELAYED_WORK(&gc->work, xfs_inodegc_worker);

	}

	return 0;

}