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Commit 59e6ae53 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller
Browse files

ptr_ring: support resizing multiple queues 



Sometimes, we need support resizing multiple queues at once. This is
because it was not easy to recover to recover from a partial failure
of multiple queues resizing.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fd68adec

include/linux/ptr_ring.h

+62 −9
Original line number Diff line number Diff line
@@ -349,20 +349,14 @@ static inline int ptr_ring_init(struct ptr_ring *r, int size, gfp_t gfp) 
	return 0;

}



static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp,

static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue,

					   int size, gfp_t gfp,

					   void (*destroy)(void *))

{

	unsigned long flags;

	int producer = 0;

	void **queue = __ptr_ring_init_queue_alloc(size, gfp);

	void **old;

	void *ptr;



	if (!queue)

		return -ENOMEM;



	spin_lock_irqsave(&(r)->producer_lock, flags);



	while ((ptr = ptr_ring_consume(r)))

		if (producer < size)

			queue[producer++] = ptr;
@@ -375,6 +369,23 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, 
	old = r->queue;

	r->queue = queue;



	return old;

}



static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp,

				  void (*destroy)(void *))

{

	unsigned long flags;

	void **queue = __ptr_ring_init_queue_alloc(size, gfp);

	void **old;



	if (!queue)

		return -ENOMEM;



	spin_lock_irqsave(&(r)->producer_lock, flags);



	old = __ptr_ring_swap_queue(r, queue, size, gfp, destroy);



	spin_unlock_irqrestore(&(r)->producer_lock, flags);



	kfree(old);
@@ -382,6 +393,48 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, 
	return 0;

}



static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings,

					   int size,

					   gfp_t gfp, void (*destroy)(void *))

{

	unsigned long flags;

	void ***queues;

	int i;



	queues = kmalloc(nrings * sizeof *queues, gfp);

	if (!queues)

		goto noqueues;



	for (i = 0; i < nrings; ++i) {

		queues[i] = __ptr_ring_init_queue_alloc(size, gfp);

		if (!queues[i])

			goto nomem;

	}



	for (i = 0; i < nrings; ++i) {

		spin_lock_irqsave(&(rings[i])->producer_lock, flags);

		queues[i] = __ptr_ring_swap_queue(rings[i], queues[i],

						  size, gfp, destroy);

		spin_unlock_irqrestore(&(rings[i])->producer_lock, flags);

	}



	for (i = 0; i < nrings; ++i)

		kfree(queues[i]);



	kfree(queues);



	return 0;



nomem:

	while (--i >= 0)

		kfree(queues[i]);



	kfree(queues);



noqueues:

	return -ENOMEM;

}



static inline void ptr_ring_cleanup(struct ptr_ring *r, void (*destroy)(void *))

{

	void *ptr;

tools/virtio/ringtest/ptr_ring.c

+5 −0
Original line number Diff line number Diff line
@@ -17,6 +17,11 @@ 
typedef pthread_spinlock_t  spinlock_t;



typedef int gfp_t;

static void *kmalloc(unsigned size, gfp_t gfp)

{

	return memalign(64, size);

}



static void *kzalloc(unsigned size, gfp_t gfp)

{

	void *p = memalign(64, size);