From 197a5212c3dd70be267b5cd930be0fb68bb53018 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 17 May 2017 12:14:37 +0800 Subject: ptr_ring: add ptr_ring_unconsume Applications that consume a batch of entries in one go can benefit from ability to return some of them back into the ring. Add an API for that - assuming there's space. If there's no space naturally can't do this and have to drop entries, but this implies ring is full so we'd likely drop some anyway. Signed-off-by: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 6b2e0dd88569..796b90f6d4e9 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -403,6 +403,61 @@ static inline int ptr_ring_init(struct ptr_ring *r, int size, gfp_t gfp) return 0; } +/* + * Return entries into ring. Destroy entries that don't fit. + * + * Note: this is expected to be a rare slow path operation. + * + * Note: producer lock is nested within consumer lock, so if you + * resize you must make sure all uses nest correctly. + * In particular if you consume ring in interrupt or BH context, you must + * disable interrupts/BH when doing so. + */ +static inline void ptr_ring_unconsume(struct ptr_ring *r, void **batch, int n, + void (*destroy)(void *)) +{ + unsigned long flags; + int head; + + spin_lock_irqsave(&r->consumer_lock, flags); + spin_lock(&r->producer_lock); + + if (!r->size) + goto done; + + /* + * Clean out buffered entries (for simplicity). This way following code + * can test entries for NULL and if not assume they are valid. + */ + head = r->consumer_head - 1; + while (likely(head >= r->consumer_tail)) + r->queue[head--] = NULL; + r->consumer_tail = r->consumer_head; + + /* + * Go over entries in batch, start moving head back and copy entries. + * Stop when we run into previously unconsumed entries. + */ + while (n) { + head = r->consumer_head - 1; + if (head < 0) + head = r->size - 1; + if (r->queue[head]) { + /* This batch entry will have to be destroyed. */ + goto done; + } + r->queue[head] = batch[--n]; + r->consumer_tail = r->consumer_head = head; + } + +done: + /* Destroy all entries left in the batch. */ + while (n) + destroy(batch[--n]); + spin_unlock(&r->producer_lock); + spin_unlock_irqrestore(&r->consumer_lock, flags); +} + static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue, int size, gfp_t gfp, void (*destroy)(void *)) -- cgit v1.2.3 From 3acb696015a222f4b25c1b5dce4e36b2d4980da6 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:38 +0800 Subject: skb_array: introduce skb_array_unconsume Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- include/linux/skb_array.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h index f4dfade428f0..79850b638bf2 100644 --- a/include/linux/skb_array.h +++ b/include/linux/skb_array.h @@ -156,6 +156,12 @@ static void __skb_array_destroy_skb(void *ptr) kfree_skb(ptr); } +static inline void skb_array_unconsume(struct skb_array *a, + struct sk_buff **skbs, int n) +{ + ptr_ring_unconsume(&a->ring, (void **)skbs, n, __skb_array_destroy_skb); +} + static inline int skb_array_resize(struct skb_array *a, int size, gfp_t gfp) { return ptr_ring_resize(&a->ring, size, gfp, __skb_array_destroy_skb); -- cgit v1.2.3 From 728fc8d5532b956f9c4b48dff0577fb722251343 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:39 +0800 Subject: ptr_ring: introduce batch dequeuing This patch introduce a batched version of consuming, consumer can dequeue more than one pointers from the ring at a time. We don't care about the reorder of reading here so no need for compiler barrier. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 796b90f6d4e9..d8c97ec8a8e6 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -278,6 +278,22 @@ static inline void *__ptr_ring_consume(struct ptr_ring *r) return ptr; } +static inline int __ptr_ring_consume_batched(struct ptr_ring *r, + void **array, int n) +{ + void *ptr; + int i; + + for (i = 0; i < n; i++) { + ptr = __ptr_ring_consume(r); + if (!ptr) + break; + array[i] = ptr; + } + + return i; +} + /* * Note: resize (below) nests producer lock within consumer lock, so if you * call this in interrupt or BH context, you must disable interrupts/BH when @@ -328,6 +344,55 @@ static inline void *ptr_ring_consume_bh(struct ptr_ring *r) return ptr; } +static inline int ptr_ring_consume_batched(struct ptr_ring *r, + void **array, int n) +{ + int ret; + + spin_lock(&r->consumer_lock); + ret = __ptr_ring_consume_batched(r, array, n); + spin_unlock(&r->consumer_lock); + + return ret; +} + +static inline int ptr_ring_consume_batched_irq(struct ptr_ring *r, + void **array, int n) +{ + int ret; + + spin_lock_irq(&r->consumer_lock); + ret = __ptr_ring_consume_batched(r, array, n); + spin_unlock_irq(&r->consumer_lock); + + return ret; +} + +static inline int ptr_ring_consume_batched_any(struct ptr_ring *r, + void **array, int n) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&r->consumer_lock, flags); + ret = __ptr_ring_consume_batched(r, array, n); + spin_unlock_irqrestore(&r->consumer_lock, flags); + + return ret; +} + +static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r, + void **array, int n) +{ + int ret; + + spin_lock_bh(&r->consumer_lock); + ret = __ptr_ring_consume_batched(r, array, n); + spin_unlock_bh(&r->consumer_lock); + + return ret; +} + /* Cast to structure type and call a function without discarding from FIFO. * Function must return a value. * Callers must take consumer_lock. -- cgit v1.2.3 From 3528c1a52e7af001e0e387fcb6bac2bdb3775d3e Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:40 +0800 Subject: skb_array: introduce batch dequeuing Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- include/linux/skb_array.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h index 79850b638bf2..35226cd4efb0 100644 --- a/include/linux/skb_array.h +++ b/include/linux/skb_array.h @@ -97,21 +97,46 @@ static inline struct sk_buff *skb_array_consume(struct skb_array *a) return ptr_ring_consume(&a->ring); } +static inline int skb_array_consume_batched(struct skb_array *a, + struct sk_buff **array, int n) +{ + return ptr_ring_consume_batched(&a->ring, (void **)array, n); +} + static inline struct sk_buff *skb_array_consume_irq(struct skb_array *a) { return ptr_ring_consume_irq(&a->ring); } +static inline int skb_array_consume_batched_irq(struct skb_array *a, + struct sk_buff **array, int n) +{ + return ptr_ring_consume_batched_irq(&a->ring, (void **)array, n); +} + static inline struct sk_buff *skb_array_consume_any(struct skb_array *a) { return ptr_ring_consume_any(&a->ring); } +static inline int skb_array_consume_batched_any(struct skb_array *a, + struct sk_buff **array, int n) +{ + return ptr_ring_consume_batched_any(&a->ring, (void **)array, n); +} + + static inline struct sk_buff *skb_array_consume_bh(struct skb_array *a) { return ptr_ring_consume_bh(&a->ring); } +static inline int skb_array_consume_batched_bh(struct skb_array *a, + struct sk_buff **array, int n) +{ + return ptr_ring_consume_batched_bh(&a->ring, (void **)array, n); +} + static inline int __skb_array_len_with_tag(struct sk_buff *skb) { if (likely(skb)) { -- cgit v1.2.3 From 83339c6b159ea6429a1db40b0d9d1083ab574733 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:41 +0800 Subject: tun: export skb_array This patch exports skb_array through tun_get_skb_array(). Caller can then manipulate skb array directly. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 13 +++++++++++++ include/linux/if_tun.h | 5 +++++ 2 files changed, 18 insertions(+) (limited to 'include/linux') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index bbd707b9ef7a..3cbfc5c707e3 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2626,6 +2626,19 @@ struct socket *tun_get_socket(struct file *file) } EXPORT_SYMBOL_GPL(tun_get_socket); +struct skb_array *tun_get_skb_array(struct file *file) +{ + struct tun_file *tfile; + + if (file->f_op != &tun_fops) + return ERR_PTR(-EINVAL); + tfile = file->private_data; + if (!tfile) + return ERR_PTR(-EBADFD); + return &tfile->tx_array; +} +EXPORT_SYMBOL_GPL(tun_get_skb_array); + module_init(tun_init); module_exit(tun_cleanup); MODULE_DESCRIPTION(DRV_DESCRIPTION); diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index ed6da2e6df90..bf9bdf42d577 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -19,6 +19,7 @@ #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE) struct socket *tun_get_socket(struct file *); +struct skb_array *tun_get_skb_array(struct file *file); #else #include #include @@ -28,5 +29,9 @@ static inline struct socket *tun_get_socket(struct file *f) { return ERR_PTR(-EINVAL); } +static inline struct skb_array *tun_get_skb_array(struct file *f) +{ + return ERR_PTR(-EINVAL); +} #endif /* CONFIG_TUN */ #endif /* __IF_TUN_H */ -- cgit v1.2.3 From 49f96fd0cb3808e5ff96573f28b3dceb16eb6998 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:42 +0800 Subject: tap: export skb_array This patch exports skb_array through tap_get_skb_array(). Caller can then manipulate skb array directly. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/tap.c | 13 +++++++++++++ include/linux/if_tap.h | 5 +++++ 2 files changed, 18 insertions(+) (limited to 'include/linux') diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 4d4173d25dd0..abdaf867774d 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1193,6 +1193,19 @@ struct socket *tap_get_socket(struct file *file) } EXPORT_SYMBOL_GPL(tap_get_socket); +struct skb_array *tap_get_skb_array(struct file *file) +{ + struct tap_queue *q; + + if (file->f_op != &tap_fops) + return ERR_PTR(-EINVAL); + q = file->private_data; + if (!q) + return ERR_PTR(-EBADFD); + return &q->skb_array; +} +EXPORT_SYMBOL_GPL(tap_get_skb_array); + int tap_queue_resize(struct tap_dev *tap) { struct net_device *dev = tap->dev; diff --git a/include/linux/if_tap.h b/include/linux/if_tap.h index 3482c3c2037d..4837157da0dc 100644 --- a/include/linux/if_tap.h +++ b/include/linux/if_tap.h @@ -3,6 +3,7 @@ #if IS_ENABLED(CONFIG_TAP) struct socket *tap_get_socket(struct file *); +struct skb_array *tap_get_skb_array(struct file *file); #else #include #include @@ -12,6 +13,10 @@ static inline struct socket *tap_get_socket(struct file *f) { return ERR_PTR(-EINVAL); } +static inline struct skb_array *tap_get_skb_array(struct file *f) +{ + return ERR_PTR(-EINVAL); +} #endif /* CONFIG_TAP */ #include -- cgit v1.2.3