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authorMichael S. Tsirkin <mst@redhat.com>2016-06-30 09:45:33 +0300
committerDavid S. Miller <davem@davemloft.net>2016-07-01 12:32:17 +0300
commit59e6ae53248a72d83cec77dd704b6990b2394479 (patch)
tree6978c2c81e9c807a544304ea2c28ce49696d3ad4 /include/linux/ptr_ring.h
parentfd68adec9de3104c236ffbcb3bd829d3e635a444 (diff)
downloadlinux-59e6ae53248a72d83cec77dd704b6990b2394479.tar.xz
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: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ptr_ring.h')
-rw-r--r--include/linux/ptr_ring.h71
1 files changed, 62 insertions, 9 deletions
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index d78b8b89c707..2052011bf9fb 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -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,
- void (*destroy)(void *))
+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;