Hello,
On 2/22/24 19:05, Chautru, Nicolas wrote:
Hi Maxime,
Why would we change this here and now? Is the intent not to use new suggested
semantics for new patches only?
The pull request was rejected because of the use of such barrier, which
is reported by checkpatch.
### [PATCH] baseband/fpga_5gnr_fec: add AGX100 support
Warning in drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c:
Using rte_smp_[r/w]mb
Are all DPDK drivers being changed?
My understanding is that for now, only new occurrences are prohibited,
can you confirm Tyler?
If so we could only change for now the patch adding ACX100.
But... I preferred doing the changes for all bbdev drivers for
consistency.
I am unsure we would want to change these drivers, this is kind of risk
introduced by code churn that gets ecosystem unwilling to move to latest
version.
I think it is better to change now that we are far from the next LTS.
These memory barriers issues are awful to troubleshoot or properly validate, so
personally quite reluctant to change.
If I disassemble fpga_dequeue_enc() with and without the patch, I cannot
spot a difference.
Thomas, are you waiting for this series to be applied to take the pull
request that was initially for -rc1?
Thanks,
Maxime
Thanks
Nic
-----Original Message-----
From: Maxime Coquelin <maxime.coque...@redhat.com>
Sent: Thursday, February 22, 2024 8:21 AM
To: dev@dpdk.org; Chautru, Nicolas <nicolas.chau...@intel.com>; Vargas,
Hernan <hernan.var...@intel.com>; Marchand, David
<david.march...@redhat.com>; tho...@monjalon.net;
roret...@linux.microsoft.com
Cc: Maxime Coquelin <maxime.coque...@redhat.com>
Subject: [PATCH 1/2] baseband/fpga_5gnr_fec: use new barrier API
rte_smp_rmb() is deprecated, use the new API instead as suggested in
rte_atomic header.
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c
b/drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c
index efc1d3a772..314c87350e 100644
--- a/drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c
+++ b/drivers/baseband/fpga_5gnr_fec/rte_fpga_5gnr_fec.c
@@ -2661,7 +2661,7 @@ vc_5gnr_dequeue_ldpc_enc_one_op_cb(struct
fpga_5gnr_queue *q, struct rte_bbdev_e
return -1;
/* make sure the response is read atomically */
- rte_smp_rmb();
+ rte_atomic_thread_fence(rte_memory_order_acquire);
rte_bbdev_log_debug("DMA response desc %p", desc);
@@ -2690,7 +2690,7 @@ agx100_dequeue_ldpc_enc_one_op_cb(struct
fpga_5gnr_queue *q, struct rte_bbdev_en
return -1;
/* make sure the response is read atomically. */
- rte_smp_rmb();
+ rte_atomic_thread_fence(rte_memory_order_acquire);
rte_bbdev_log_debug("DMA response desc %p", desc);
@@ -2722,7 +2722,7 @@ vc_5gnr_dequeue_ldpc_dec_one_op_cb(struct
fpga_5gnr_queue *q, struct rte_bbdev_d
return -1;
/* make sure the response is read atomically */
- rte_smp_rmb();
+ rte_atomic_thread_fence(rte_memory_order_acquire);
#ifdef RTE_LIBRTE_BBDEV_DEBUG
vc_5gnr_print_dma_dec_desc_debug_info(desc);
@@ -2768,7 +2768,7 @@ agx100_dequeue_ldpc_dec_one_op_cb(struct
fpga_5gnr_queue *q, struct rte_bbdev_de
return -1;
/* make sure the response is read atomically. */
- rte_smp_rmb();
+ rte_atomic_thread_fence(rte_memory_order_acquire);
#ifdef RTE_LIBRTE_BBDEV_DEBUG
agx100_print_dma_dec_desc_debug_info(desc);
--
2.43.0
