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Commit bdfafc4f authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

locking/atomic, kref: Kill kref_sub() 



By general sentiment kref_sub() is a bad interface, make it go away.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 2c935bc5

drivers/block/drbd/drbd_main.c

+4 −3
Original line number Diff line number Diff line
@@ -2948,7 +2948,6 @@ void drbd_delete_device(struct drbd_device *device) 
	struct drbd_resource *resource = device->resource;

	struct drbd_connection *connection;

	struct drbd_peer_device *peer_device;

	int refs = 3;



	/* move to free_peer_device() */

	for_each_peer_device(peer_device, device)
@@ -2956,13 +2955,15 @@ void drbd_delete_device(struct drbd_device *device) 
	drbd_debugfs_device_cleanup(device);

	for_each_connection(connection, resource) {

		idr_remove(&connection->peer_devices, device->vnr);

		refs++;

		kref_put(&device->kref, drbd_destroy_device);

	}

	idr_remove(&resource->devices, device->vnr);

	kref_put(&device->kref, drbd_destroy_device);

	idr_remove(&drbd_devices, device_to_minor(device));

	kref_put(&device->kref, drbd_destroy_device);

	del_gendisk(device->vdisk);

	synchronize_rcu();

	kref_sub(&device->kref, refs, drbd_destroy_device);

	kref_put(&device->kref, drbd_destroy_device);

}



static int __init drbd_init(void)

drivers/block/drbd/drbd_req.c

+10 −21
Original line number Diff line number Diff line
@@ -421,7 +421,6 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, 
	struct drbd_peer_device *peer_device = first_peer_device(device);

	unsigned s = req->rq_state;

	int c_put = 0;

	int k_put = 0;



	if (drbd_suspended(device) && !((s | clear) & RQ_COMPLETION_SUSP))

		set |= RQ_COMPLETION_SUSP;
@@ -437,6 +436,8 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, 


	/* intent: get references */



	kref_get(&req->kref);



	if (!(s & RQ_LOCAL_PENDING) && (set & RQ_LOCAL_PENDING))

		atomic_inc(&req->completion_ref);
@@ -473,15 +474,12 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, 


	if (!(s & RQ_LOCAL_ABORTED) && (set & RQ_LOCAL_ABORTED)) {

		D_ASSERT(device, req->rq_state & RQ_LOCAL_PENDING);

		/* local completion may still come in later,

		 * we need to keep the req object around. */

		kref_get(&req->kref);

		++c_put;

	}



	if ((s & RQ_LOCAL_PENDING) && (clear & RQ_LOCAL_PENDING)) {

		if (req->rq_state & RQ_LOCAL_ABORTED)

			++k_put;

			kref_put(&req->kref, drbd_req_destroy);

		else

			++c_put;

		list_del_init(&req->req_pending_local);
@@ -503,7 +501,7 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, 
		if (s & RQ_NET_SENT)

			atomic_sub(req->i.size >> 9, &device->ap_in_flight);

		if (s & RQ_EXP_BARR_ACK)

			++k_put;

			kref_put(&req->kref, drbd_req_destroy);

		req->net_done_jif = jiffies;



		/* in ahead/behind mode, or just in case,
@@ -516,25 +514,16 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, 


	/* potentially complete and destroy */



	if (k_put || c_put) {

		/* Completion does it's own kref_put.  If we are going to

		 * kref_sub below, we need req to be still around then. */

		int at_least = k_put + !!c_put;

		int refcount = kref_read(&req->kref);

		if (refcount < at_least)

			drbd_err(device,

				"mod_rq_state: Logic BUG: %x -> %x: refcount = %d, should be >= %d\n",

				s, req->rq_state, refcount, at_least);

	}



	/* If we made progress, retry conflicting peer requests, if any. */

	if (req->i.waiting)

		wake_up(&device->misc_wait);



	if (c_put)

		k_put += drbd_req_put_completion_ref(req, m, c_put);

	if (k_put)

		kref_sub(&req->kref, k_put, drbd_req_destroy);

	if (c_put) {

		if (drbd_req_put_completion_ref(req, m, c_put))

			kref_put(&req->kref, drbd_req_destroy);

	} else {

		kref_put(&req->kref, drbd_req_destroy);

	}

}



static void drbd_report_io_error(struct drbd_device *device, struct drbd_request *req)

drivers/gpu/drm/ttm/ttm_bo.c

+16 −43
Original line number Diff line number Diff line
@@ -181,61 +181,46 @@ void ttm_bo_add_to_lru(struct ttm_buffer_object *bo) 
}

EXPORT_SYMBOL(ttm_bo_add_to_lru);



int ttm_bo_del_from_lru(struct ttm_buffer_object *bo)

static void ttm_bo_ref_bug(struct kref *list_kref)

{

	BUG();

}



void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)

{

	struct ttm_bo_device *bdev = bo->bdev;

	int put_count = 0;



	if (bdev->driver->lru_removal)

		bdev->driver->lru_removal(bo);



	if (!list_empty(&bo->swap)) {

		list_del_init(&bo->swap);

		++put_count;

		kref_put(&bo->list_kref, ttm_bo_ref_bug);

	}

	if (!list_empty(&bo->lru)) {

		list_del_init(&bo->lru);

		++put_count;

		kref_put(&bo->list_kref, ttm_bo_ref_bug);

	}



	return put_count;

}



static void ttm_bo_ref_bug(struct kref *list_kref)

{

	BUG();

}



void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,

			 bool never_free)

{

	kref_sub(&bo->list_kref, count,

		 (never_free) ? ttm_bo_ref_bug : ttm_bo_release_list);

}



void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo)

{

	int put_count;



	spin_lock(&bo->glob->lru_lock);

	put_count = ttm_bo_del_from_lru(bo);

	ttm_bo_del_from_lru(bo);

	spin_unlock(&bo->glob->lru_lock);

	ttm_bo_list_ref_sub(bo, put_count, true);

}

EXPORT_SYMBOL(ttm_bo_del_sub_from_lru);



void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo)

{

	struct ttm_bo_device *bdev = bo->bdev;

	int put_count = 0;



	lockdep_assert_held(&bo->resv->lock.base);



	if (bdev->driver->lru_removal)

		bdev->driver->lru_removal(bo);



	put_count = ttm_bo_del_from_lru(bo);

	ttm_bo_list_ref_sub(bo, put_count, true);

	ttm_bo_del_from_lru(bo);

	ttm_bo_add_to_lru(bo);

}

EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
@@ -447,7 +432,6 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo) 
{

	struct ttm_bo_device *bdev = bo->bdev;

	struct ttm_bo_global *glob = bo->glob;

	int put_count;

	int ret;



	spin_lock(&glob->lru_lock);
@@ -455,13 +439,10 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo) 


	if (!ret) {

		if (!ttm_bo_wait(bo, false, true)) {

			put_count = ttm_bo_del_from_lru(bo);



			ttm_bo_del_from_lru(bo);

			spin_unlock(&glob->lru_lock);

			ttm_bo_cleanup_memtype_use(bo);



			ttm_bo_list_ref_sub(bo, put_count, true);



			return;

		} else

			ttm_bo_flush_all_fences(bo);
@@ -504,7 +485,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo, 
					  bool no_wait_gpu)

{

	struct ttm_bo_global *glob = bo->glob;

	int put_count;

	int ret;



	ret = ttm_bo_wait(bo, false, true);
@@ -554,15 +534,13 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo, 
		return ret;

	}



	put_count = ttm_bo_del_from_lru(bo);

	ttm_bo_del_from_lru(bo);

	list_del_init(&bo->ddestroy);

	++put_count;

	kref_put(&bo->list_kref, ttm_bo_ref_bug);



	spin_unlock(&glob->lru_lock);

	ttm_bo_cleanup_memtype_use(bo);



	ttm_bo_list_ref_sub(bo, put_count, true);



	return 0;

}
@@ -740,7 +718,7 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev, 
	struct ttm_bo_global *glob = bdev->glob;

	struct ttm_mem_type_manager *man = &bdev->man[mem_type];

	struct ttm_buffer_object *bo;

	int ret = -EBUSY, put_count;

	int ret = -EBUSY;



	spin_lock(&glob->lru_lock);

	list_for_each_entry(bo, &man->lru, lru) {
@@ -771,13 +749,11 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev, 
		return ret;

	}



	put_count = ttm_bo_del_from_lru(bo);

	ttm_bo_del_from_lru(bo);

	spin_unlock(&glob->lru_lock);



	BUG_ON(ret != 0);



	ttm_bo_list_ref_sub(bo, put_count, true);



	ret = ttm_bo_evict(bo, interruptible, no_wait_gpu);

	ttm_bo_unreserve(bo);
@@ -1669,7 +1645,6 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink) 
	    container_of(shrink, struct ttm_bo_global, shrink);

	struct ttm_buffer_object *bo;

	int ret = -EBUSY;

	int put_count;

	uint32_t swap_placement = (TTM_PL_FLAG_CACHED | TTM_PL_FLAG_SYSTEM);



	spin_lock(&glob->lru_lock);
@@ -1692,11 +1667,9 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink) 
		return ret;

	}



	put_count = ttm_bo_del_from_lru(bo);

	ttm_bo_del_from_lru(bo);

	spin_unlock(&glob->lru_lock);



	ttm_bo_list_ref_sub(bo, put_count, true);



	/**

	 * Move to system cached

	 */

drivers/gpu/drm/ttm/ttm_execbuf_util.c

+1 −3
Original line number Diff line number Diff line
@@ -48,9 +48,7 @@ static void ttm_eu_del_from_lru_locked(struct list_head *list) 


	list_for_each_entry(entry, list, head) {

		struct ttm_buffer_object *bo = entry->bo;

		unsigned put_count = ttm_bo_del_from_lru(bo);



		ttm_bo_list_ref_sub(bo, put_count, true);

		ttm_bo_del_from_lru(bo);

	}

}

include/drm/ttm/ttm_bo_api.h

+1 −14
Original line number Diff line number Diff line
@@ -332,19 +332,6 @@ extern int ttm_bo_validate(struct ttm_buffer_object *bo, 
 */

extern void ttm_bo_unref(struct ttm_buffer_object **bo);





/**

 * ttm_bo_list_ref_sub

 *

 * @bo: The buffer object.

 * @count: The number of references with which to decrease @bo::list_kref;

 * @never_free: The refcount should not reach zero with this operation.

 *

 * Release @count lru list references to this buffer object.

 */

extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,

				bool never_free);



/**

 * ttm_bo_add_to_lru

 *
@@ -367,7 +354,7 @@ extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo); 
 * and is usually called just immediately after the bo has been reserved to

 * avoid recursive reservation from lru lists.

 */

extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);

extern void ttm_bo_del_from_lru(struct ttm_buffer_object *bo);



/**

 * ttm_bo_move_to_lru_tail