search for: __ptr_ring_produce

...ol ptr_ring_full_bh(struct ptr_ring *r) /* Note: callers invoking this in a loop must use a compiler barrier, * for example cpu_relax(). Callers must hold producer_lock. + * Callers are responsible for making sure pointer that is being queued + * points to a valid data. */ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; + /* Make sure the pointer we are storing points to a valid data. */ + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ + smp_wmb(); + r->queue[r->producer++] =...

...ol ptr_ring_full_bh(struct ptr_ring *r) /* Note: callers invoking this in a loop must use a compiler barrier, * for example cpu_relax(). Callers must hold producer_lock. + * Callers are responsible for making sure pointer that is being queued + * points to a valid data. */ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; + /* Make sure the pointer we are storing points to a valid data. */ + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ + smp_wmb(); + r->queue[r->producer++] =...

...allers invoking this in a loop must use a compiler barrier, > > * for example cpu_relax(). Callers must hold producer_lock. > > + * Callers are responsible for making sure pointer that is being queued > > + * points to a valid data. > > */ > > static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > > { > > if (unlikely(!r->size) || r->queue[r->producer]) > > return -ENOSPC; > > + /* Make sure the pointer we are storing points to a valid data. */ > > + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume....

...allers invoking this in a loop must use a compiler barrier, > > * for example cpu_relax(). Callers must hold producer_lock. > > + * Callers are responsible for making sure pointer that is being queued > > + * points to a valid data. > > */ > > static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > > { > > if (unlikely(!r->size) || r->queue[r->producer]) > > return -ENOSPC; > > + /* Make sure the pointer we are storing points to a valid data. */ > > + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume....

...n at cavium.com> --- include/linux/ptr_ring.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 37b4bb2..bc3b36b 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -106,6 +106,12 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; + /* + * This barrier is necessary in order to prevent race condition with + * with __ptr_ring_consume(). By this we make sure all the prior + * writes to *ptr elements are updated....

...n at cavium.com> --- include/linux/ptr_ring.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 37b4bb2..bc3b36b 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -106,6 +106,12 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; + /* + * This barrier is necessary in order to prevent race condition with + * with __ptr_ring_consume(). By this we make sure all the prior + * writes to *ptr elements are updated....

...> > /* Note: callers invoking this in a loop must use a compiler barrier, > * for example cpu_relax(). Callers must hold producer_lock. > + * Callers are responsible for making sure pointer that is being queued > + * points to a valid data. > */ > static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > { > if (unlikely(!r->size) || r->queue[r->producer]) > return -ENOSPC; > > + /* Make sure the pointer we are storing points to a valid data. */ > + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ > + smp_wmb...

...linux/ptr_ring.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h > index 37b4bb2..bc3b36b 100644 > --- a/include/linux/ptr_ring.h > +++ b/include/linux/ptr_ring.h > @@ -106,6 +106,12 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > { > if (unlikely(!r->size) || r->queue[r->producer]) > return -ENOSPC; > + /* > + * This barrier is necessary in order to prevent race condition with > + * with __ptr_ring_consume(). By this we make sure all the prior > + * writes to *p...

...linux/ptr_ring.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h > index 37b4bb2..bc3b36b 100644 > --- a/include/linux/ptr_ring.h > +++ b/include/linux/ptr_ring.h > @@ -106,6 +106,12 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > { > if (unlikely(!r->size) || r->queue[r->producer]) > return -ENOSPC; > + /* > + * This barrier is necessary in order to prevent race condition with > + * with __ptr_ring_consume(). By this we make sure all the prior > + * writes to *p...

...> > /* Note: callers invoking this in a loop must use a compiler barrier, > * for example cpu_relax(). Callers must hold producer_lock. > + * Callers are responsible for making sure pointer that is being queued > + * points to a valid data. > */ > static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > { > if (unlikely(!r->size) || r->queue[r->producer]) > return -ENOSPC; > > + /* Make sure the pointer we are storing points to a valid data. */ > + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ > + smp_wmb...

...allers invoking this in a loop must use a compiler barrier, > > * for example cpu_relax(). Callers must hold producer_lock. > > + * Callers are responsible for making sure pointer that is being queued > > + * points to a valid data. > > */ > > static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > > { > > if (unlikely(!r->size) || r->queue[r->producer]) > > return -ENOSPC; > > + /* Make sure the pointer we are storing points to a valid data. */ > > + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume....

...nux/ptr_ring.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h > index 37b4bb2..bc3b36b 100644 > --- a/include/linux/ptr_ring.h > +++ b/include/linux/ptr_ring.h > @@ -106,6 +106,12 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) > { > if (unlikely(!r->size) || r->queue[r->producer]) > return -ENOSPC; > + /* > + * This barrier is necessary in order to prevent race condition with > + * with __ptr_ring_consume(). By this we make sure all the prior > + * wri...

..., Cherian, George wrote: > > @@ -275,6 +281,13 @@ static inline void *__ptr_ring_consume(struct ptr_ring > *r) > > if (ptr) > > __ptr_ring_discard_one(r); > > > > + /* > > + * This barrier is necessary in order to prevent race condition with > > + * with __ptr_ring_produce(). Make sure all the elements of ptr is > > + * in sync with the earlier writes which was done prior to pushing > > + * it to ring > > + */ > > + rmb(); > > return ptr; > > } > > You are trying to synchronise two CPUs so non-smp barriers make no > sense...

...adcnt, tailcnt; +static struct ptr_ring array ____cacheline_aligned_in_smp; + +/* implemented by ring */ +void alloc_ring(void) +{ + int ret = ptr_ring_init(&array, ring_size, 0); + assert(!ret); +} + +/* guest side */ +int add_inbuf(unsigned len, void *buf, void *datap) +{ + int ret; + + ret = __ptr_ring_produce(&array, buf); + if (ret >= 0) { + ret = 0; + headcnt++; + } + + return ret; +} + +/* + * ptr_ring API provides no way for producer to find out whether a given + * buffer was consumed. Our tests merely require that a successful get_buf + * implies that add_inbuf succeed in the past, and th...

...adcnt, tailcnt; +static struct ptr_ring array ____cacheline_aligned_in_smp; + +/* implemented by ring */ +void alloc_ring(void) +{ + int ret = ptr_ring_init(&array, ring_size, 0); + assert(!ret); +} + +/* guest side */ +int add_inbuf(unsigned len, void *buf, void *datap) +{ + int ret; + + ret = __ptr_ring_produce(&array, buf); + if (ret >= 0) { + ret = 0; + headcnt++; + } + + return ret; +} + +/* + * ptr_ring API provides no way for producer to find out whether a given + * buffer was consumed. Our tests merely require that a successful get_buf + * implies that add_inbuf succeed in the past, and th...

Hi all: This series tries to switch to use skb array in tun. This is used to eliminate the spinlock contention between producer and consumer. The conversion was straightforward: just introdce a tx skb array and use it instead of sk_receive_queue. A minor issue is to keep the tx_queue_len behaviour, since tun used to use it for the length of sk_receive_queue. This is done through: - add the

Hi all: This series tries to switch to use skb array in tun. This is used to eliminate the spinlock contention between producer and consumer. The conversion was straightforward: just introdce a tx skb array and use it instead of sk_receive_queue. A minor issue is to keep the tx_queue_len behaviour, since tun used to use it for the length of sk_receive_queue. This is done through: - add the

Hi all: This series tries to switch to use skb array in tun. This is used to eliminate the spinlock contention between producer and consumer. The conversion was straightforward: just introdce a tx skb array and use it instead of sk_receive_queue. A minor issue is to keep the tx_queue_len behaviour, since tun used to use it for the length of sk_receive_queue. This is done through: - add the

Hi all: This series tries to switch to use skb array in tun. This is used to eliminate the spinlock contention between producer and consumer. The conversion was straightforward: just introdce a tx skb array and use it instead of sk_receive_queue. A minor issue is to keep the tx_queue_len behaviour, since tun used to use it for the length of sk_receive_queue. This is done through: - add the

Hi all, Although [smp_]read_barrier_depends() became part of READ_ONCE() in commit 76ebbe78f739 ("locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()"), it still limps on in the Linux memory model with the sinister hope of attracting innocent new users so that it becomes impossible to remove altogether. Let's strike before it's too late: there's only