[dpdk-dev,v8,3/3] ring: introduce new header file to support C11 memory model
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Commit Message
To support C11 memory model barrier, 2 options are suggested by Jerin:
1. use rte_smp_rmb
2. use load_acquire/store_release(refer to [1]).
CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
on any architectures so far.
The reason why providing 2 options is due to the performance benchmark
difference in different arm machines, refer to [2].
We haven't tested on ppc64. If anyone verifies it, he can add
CONFIG_RTE_RING_USE_C11_MEM_MODEL=y to ppc64 config files.
[1] https://github.com/freebsd/freebsd/blob/master/sys/sys/buf_ring.h#L170
[2] http://dpdk.org/ml/archives/dev/2017-October/080861.html
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Suggested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Jianbo Liu <jianbo.liu@arm.com>
---
config/common_linuxapp | 2 +
lib/librte_ring/Makefile | 3 +-
lib/librte_ring/rte_ring.h | 14 ++-
lib/librte_ring/rte_ring_c11_mem.h | 193 +++++++++++++++++++++++++++++++++++++
4 files changed, 210 insertions(+), 2 deletions(-)
create mode 100644 lib/librte_ring/rte_ring_c11_mem.h
Comments
17/01/2018 05:03, Jia He:
> To support C11 memory model barrier, 2 options are suggested by Jerin:
> 1. use rte_smp_rmb
> 2. use load_acquire/store_release(refer to [1]).
> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
> on any architectures so far.
In previous patches, it was enabled for ARM.
You decided to not enable it at all?
> config/common_linuxapp | 2 +
It should be defined in common_base, not common_linuxapp.
> --- /dev/null
> +++ b/lib/librte_ring/rte_ring_c11_mem.h
> @@ -0,0 +1,193 @@
> +/*-
> + * Copyright(c) 2017 Intel Corporation. All rights reserved.
> + * All rights reserved.
> + *
> + * SPDX-License-Identifier: BSD-3-Clause
> + */
It is not complying with the template.
Please check the license/ directory.
Why is it Intel Copyright?
"All rights reserved" is probably not needed.
> +/*
> + * Derived from FreeBSD's bufring.h
> + *
> + **************************************************************************
> + *
> + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
> + * All rights reserved.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright notice,
> + * this list of conditions and the following disclaimer.
> + *
> + * 2. The name of Kip Macy nor the names of other
> + * contributors may be used to endorse or promote products derived from
> + * this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> + * POSSIBILITY OF SUCH DAMAGE.
> + *
> + ***************************************************************************/
This double license may be an issue.
Hemant, comment?
Hi Thomas
On 1/17/2018 4:24 PM, Thomas Monjalon Wrote:
> 17/01/2018 05:03, Jia He:
>> To support C11 memory model barrier, 2 options are suggested by Jerin:
>> 1. use rte_smp_rmb
>> 2. use load_acquire/store_release(refer to [1]).
>> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
>> on any architectures so far.
> In previous patches, it was enabled for ARM.
> You decided to not enable it at all?
Sorry, maybe I misunderstand your previous mail.
>This config option should be added in the common file (as disabled).
Do you mean CONFIG_RTE_RING_USE_C11_MEM_MODEL=n in comm_base and
"y" in armv8 config?
Cheers,
Jia
>
>> config/common_linuxapp | 2 +
> It should be defined in common_base, not common_linuxapp.
>
>> --- /dev/null
>> +++ b/lib/librte_ring/rte_ring_c11_mem.h
>> @@ -0,0 +1,193 @@
>> +/*-
>> + * Copyright(c) 2017 Intel Corporation. All rights reserved.
>> + * All rights reserved.
>> + *
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + */
> It is not complying with the template.
> Please check the license/ directory.
>
> Why is it Intel Copyright?
> "All rights reserved" is probably not needed.
>
>> +/*
>> + * Derived from FreeBSD's bufring.h
>> + *
>> + **************************************************************************
>> + *
>> + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
>> + * All rights reserved.
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright notice,
>> + * this list of conditions and the following disclaimer.
>> + *
>> + * 2. The name of Kip Macy nor the names of other
>> + * contributors may be used to endorse or promote products derived from
>> + * this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
>> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
>> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
>> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
>> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
>> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
>> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
>> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
>> + * POSSIBILITY OF SUCH DAMAGE.
>> + *
>> + ***************************************************************************/
> This double license may be an issue.
> Hemant, comment?
>
17/01/2018 09:47, Jia He:
>
> Hi Thomas
>
> On 1/17/2018 4:24 PM, Thomas Monjalon Wrote:
> > 17/01/2018 05:03, Jia He:
> >> To support C11 memory model barrier, 2 options are suggested by Jerin:
> >> 1. use rte_smp_rmb
> >> 2. use load_acquire/store_release(refer to [1]).
> >> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
> >> on any architectures so far.
> > In previous patches, it was enabled for ARM.
> > You decided to not enable it at all?
> Sorry, maybe I misunderstand your previous mail.
> >This config option should be added in the common file (as disabled).
> Do you mean CONFIG_RTE_RING_USE_C11_MEM_MODEL=n in comm_base and
> "y" in armv8 config?
Yes, exactly
17/01/2018 10:09, Thomas Monjalon:
> 17/01/2018 09:47, Jia He:
> >
> > Hi Thomas
> >
> > On 1/17/2018 4:24 PM, Thomas Monjalon Wrote:
> > > 17/01/2018 05:03, Jia He:
> > >> To support C11 memory model barrier, 2 options are suggested by Jerin:
> > >> 1. use rte_smp_rmb
> > >> 2. use load_acquire/store_release(refer to [1]).
> > >> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
> > >> on any architectures so far.
> > > In previous patches, it was enabled for ARM.
> > > You decided to not enable it at all?
> > Sorry, maybe I misunderstand your previous mail.
> > >This config option should be added in the common file (as disabled).
> > Do you mean CONFIG_RTE_RING_USE_C11_MEM_MODEL=n in comm_base and
> > "y" in armv8 config?
>
> Yes, exactly
Please, could you send a v9?
Thanks
On 1/19/2018 7:52 AM, Thomas Monjalon Wrote:
> 17/01/2018 10:09, Thomas Monjalon:
>> 17/01/2018 09:47, Jia He:
>>> Hi Thomas
>>>
>>> On 1/17/2018 4:24 PM, Thomas Monjalon Wrote:
>>>> 17/01/2018 05:03, Jia He:
>>>>> To support C11 memory model barrier, 2 options are suggested by Jerin:
>>>>> 1. use rte_smp_rmb
>>>>> 2. use load_acquire/store_release(refer to [1]).
>>>>> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
>>>>> on any architectures so far.
>>>> In previous patches, it was enabled for ARM.
>>>> You decided to not enable it at all?
>>> Sorry, maybe I misunderstand your previous mail.
>>> >This config option should be added in the common file (as disabled).
>>> Do you mean CONFIG_RTE_RING_USE_C11_MEM_MODEL=n in comm_base and
>>> "y" in armv8 config?
>> Yes, exactly
> Please, could you send a v9?
> Thanks
>>This double license may be an issue.
>>Hemant, comment?
Ok， should I remove the double license info before Hemant's confirmation?
HI Jia,
On 1/17/2018 2:17 PM, Jia He wrote:
>
> Hi Thomas
>
> On 1/17/2018 4:24 PM, Thomas Monjalon Wrote:
>> 17/01/2018 05:03, Jia He:
>>> To support C11 memory model barrier, 2 options are suggested by Jerin:
>>> 1. use rte_smp_rmb
>>> 2. use load_acquire/store_release(refer to [1]).
>>> CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
>>> on any architectures so far.
>> In previous patches, it was enabled for ARM.
>> You decided to not enable it at all?
> Sorry, maybe I misunderstand your previous mail.
>>This config option should be added in the common file (as disabled).
> Do you mean CONFIG_RTE_RING_USE_C11_MEM_MODEL=n in comm_base and
> "y" in armv8 config?
>
> Cheers,
> Jia
>>
>>> config/common_linuxapp | 2 +
>> It should be defined in common_base, not common_linuxapp.
>>
>>> --- /dev/null
>>> +++ b/lib/librte_ring/rte_ring_c11_mem.h
>>> @@ -0,0 +1,193 @@
>>> +/*-
>>> + * Copyright(c) 2017 Intel Corporation. All rights reserved.
>>> + * All rights reserved.
>>> + *
>>> + * SPDX-License-Identifier: BSD-3-Clause
>>> + */
>> It is not complying with the template.
>> Please check the license/ directory.
>>
>> Why is it Intel Copyright?
>> "All rights reserved" is probably not needed.
SPDX shall be first line.
Agree, why are you copyrighting it to Intel?
>>
>>> +/*
>>> + * Derived from FreeBSD's bufring.h
>>> + *
>>> +
>>> **************************************************************************
>>>
>>> + *
>>> + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
>>> + * All rights reserved.
>>> + *
>>> + * Redistribution and use in source and binary forms, with or without
>>> + * modification, are permitted provided that the following
>>> conditions are met:
>>> + *
>>> + * 1. Redistributions of source code must retain the above copyright
>>> notice,
>>> + * this list of conditions and the following disclaimer.
>>> + *
>>> + * 2. The name of Kip Macy nor the names of other
>>> + * contributors may be used to endorse or promote products
>>> derived from
>>> + * this software without specific prior written permission.
>>> + *
>>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
>>> CONTRIBUTORS "AS IS"
>>> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
>>> TO, THE
>>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
>>> PARTICULAR PURPOSE
>>> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
>>> CONTRIBUTORS BE
>>> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
>>> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
>>> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
>>> BUSINESS
>>> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
>>> WHETHER IN
>>> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
>>> OTHERWISE)
>>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
>>> ADVISED OF THE
>>> + * POSSIBILITY OF SUCH DAMAGE.
>>> + *
>>> +
>>> ***************************************************************************/
>>>
>> This double license may be an issue.
>> Hemant, comment?
>>
>
Check my response in your other patch. This is not a DPDK acceptable
license. It need approval from GB.
I could not locate a BSD-3 version of bufring.h
What can be accepted in this case, without GB approval:
BSD-3 only license
+ Keep copyright of Kip Macy
+ Put statement that Kip Macy allowed it for BSD-3 uses. Or, Your
company (the copyright owner) is re-licensing the original
"BSD-2-freebsd" as "BSD-3".
+ keep the Derived from statement.
My thunderbird mails are getting delayed.
I have provided a response there that this patch is not ok in it's current state.
@@ -50,3 +50,5 @@ CONFIG_RTE_LIBRTE_AVP_PMD=y
CONFIG_RTE_LIBRTE_NFP_PMD=y
CONFIG_RTE_LIBRTE_POWER=y
CONFIG_RTE_VIRTIO_USER=y
+
+CONFIG_RTE_RING_USE_C11_MEM_MODEL=n
@@ -18,6 +18,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_RING) := rte_ring.c
# install includes
SYMLINK-$(CONFIG_RTE_LIBRTE_RING)-include := rte_ring.h \
- rte_ring_generic.h
+ rte_ring_generic.h \
+ rte_ring_c11_mem.h
include $(RTE_SDK)/mk/rte.lib.mk
@@ -356,8 +356,20 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
} \
} while (0)
-/* Move common functions to generic file */
+/* Between load and load. there might be cpu reorder in weak model
+ * (powerpc/arm).
+ * There are 2 choices for the users
+ * 1.use rmb() memory barrier
+ * 2.use one-direcion load_acquire/store_release barrier,defined by
+ * CONFIG_RTE_RING_USE_C11_MEM_MODEL=y
+ * It depends on performance test results.
+ * By default, move common functions to rte_ring_generic.h
+ */
+#ifdef RTE_RING_USE_C11_MEM_MODEL
+#include "rte_ring_c11_mem.h"
+#else
#include "rte_ring_generic.h"
+#endif
/**
* @internal Enqueue several objects on the ring
new file mode 100644
@@ -0,0 +1,193 @@
+/*-
+ * Copyright(c) 2017 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * Derived from FreeBSD's bufring.h
+ *
+ **************************************************************************
+ *
+ * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. The name of Kip Macy nor the names of other
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ***************************************************************************/
+
+#ifndef _RTE_RING_C11_MEM_H_
+#define _RTE_RING_C11_MEM_H_
+
+static __rte_always_inline void
+update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
+ uint32_t single, uint32_t enqueue)
+{
+ RTE_SET_USED(enqueue);
+
+ /*
+ * If there are other enqueues/dequeues in progress that preceded us,
+ * we need to wait for them to complete
+ */
+ if (!single)
+ while (unlikely(ht->tail != old_val))
+ rte_pause();
+
+ __atomic_store_n(&ht->tail, new_val, __ATOMIC_RELEASE);
+}
+
+/**
+ * @internal This function updates the producer head for enqueue
+ *
+ * @param r
+ * A pointer to the ring structure
+ * @param is_sp
+ * Indicates whether multi-producer path is needed or not
+ * @param n
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where enqueue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where enqueue finishes
+ * @param free_entries
+ * Returns the amount of free space in the ring BEFORE head was moved
+ * @return
+ * Actual number of objects enqueued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
+ */
+static __rte_always_inline unsigned int
+__rte_ring_move_prod_head(struct rte_ring *r, int is_sp,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *free_entries)
+{
+ const uint32_t capacity = r->capacity;
+ unsigned int max = n;
+ int success;
+
+ do {
+ /* Reset n to the initial burst count */
+ n = max;
+
+ *old_head = __atomic_load_n(&r->prod.head,
+ __ATOMIC_ACQUIRE);
+ const uint32_t cons_tail = r->cons.tail;
+ /*
+ * The subtraction is done between two unsigned 32bits value
+ * (the result is always modulo 32 bits even if we have
+ * *old_head > cons_tail). So 'free_entries' is always between 0
+ * and capacity (which is < size).
+ */
+ *free_entries = (capacity + cons_tail - *old_head);
+
+ /* check that we have enough room in ring */
+ if (unlikely(n > *free_entries))
+ n = (behavior == RTE_RING_QUEUE_FIXED) ?
+ 0 : *free_entries;
+
+ if (n == 0)
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sp)
+ r->prod.head = *new_head, success = 1;
+ else
+ success = __atomic_compare_exchange_n(&r->prod.head,
+ old_head, *new_head,
+ 0, __ATOMIC_ACQUIRE,
+ __ATOMIC_RELAXED);
+ } while (unlikely(success == 0));
+ return n;
+}
+
+/**
+ * @internal This function updates the consumer head for dequeue
+ *
+ * @param r
+ * A pointer to the ring structure
+ * @param is_sc
+ * Indicates whether multi-consumer path is needed or not
+ * @param n
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where dequeue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where dequeue finishes
+ * @param entries
+ * Returns the number of entries in the ring BEFORE head was moved
+ * @return
+ * - Actual number of objects dequeued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
+ */
+static __rte_always_inline unsigned int
+__rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *entries)
+{
+ unsigned int max = n;
+ int success;
+
+ /* move cons.head atomically */
+ do {
+ /* Restore n as it may change every loop */
+ n = max;
+ *old_head = __atomic_load_n(&r->cons.head,
+ __ATOMIC_ACQUIRE);
+ const uint32_t prod_tail = r->prod.tail;
+ /* The subtraction is done between two unsigned 32bits value
+ * (the result is always modulo 32 bits even if we have
+ * cons_head > prod_tail). So 'entries' is always between 0
+ * and size(ring)-1.
+ */
+ *entries = (prod_tail - *old_head);
+
+ /* Set the actual entries for dequeue */
+ if (n > *entries)
+ n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : *entries;
+
+ if (unlikely(n == 0))
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sc)
+ r->cons.head = *new_head, success = 1;
+ else
+ success = __atomic_compare_exchange_n(&r->cons.head,
+ old_head, *new_head,
+ 0, __ATOMIC_ACQUIRE,
+ __ATOMIC_RELAXED);
+ } while (unlikely(success == 0));
+ return n;
+}
+
+#endif /* _RTE_RING_C11_MEM_H_ */