RE: [PATCH] net/mlx5: remove redundant "set used"

[Slava Ovsiienko <viacheslavo@nvidia.com>]

Hi, Ferruh

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Thursday, November 11, 2021 14:08
> To: Slava Ovsiienko <viacheslavo@nvidia.com>; dev@dpdk.org
> Cc: Raslan Darawsheh <rasland@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; stable@dpdk.org; Chengfeng Ye
> <cyeaa@connect.ust.hk>
> Subject: Re: [PATCH] net/mlx5: remove redundant "set used"
> 
> On 11/11/2021 8:59 AM, Slava Ovsiienko wrote:
> > Hi, Ferruh
> >
> > I've also inspected the mlx5 PMD code for RTE_SET_USED() for the
> > similar issues related to the MLX5_ASSERT().
> >
> > The patch
> > http://patches.dpdk.org/project/dpdk/patch/20211111084751.26721-1-
> viac
> > heslavo@nvidia.com/
> > should refine the few found ones.
> >
> > I do not mind about squashing with "net/mlx5: fix mutex unlock in txpp
> cleanup"
> > After getting this code in Upstream will care about the version for LTS.
> >
> 
> It will cause additional complexity for the LTS, since a small part of the below
> fix will be originated from Chengfeng's change. To help LTS, what do you think
> - First get your fix on top of current task
> - Have a new version from Chengfeng on top of latest head, with 'claim_zero'
> usage?
Would be nice, I have no any objections.
Chengfeng, could you please, squash (or write by yourself) my proposed updates
and send the next version of your patch with "claim_zero()"?

> So only your update need to be merged to LTS releases.
Yes, agree, it is even better than my proposal.

With best regards,
Slava

> >
> >> -----Original Message-----
> >> From: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> >> Sent: Thursday, November 11, 2021 10:48
> >> To: dev@dpdk.org
> >> Cc: ferruh.yigit@intel.com; Raslan Darawsheh <rasland@nvidia.com>;
> >> Matan Azrad <matan@nvidia.com>; stable@dpdk.org
> >> Subject: [PATCH] net/mlx5: remove redundant "set used"
> >>
> >> The patch just refines the code and replaces the pairs of
> >> MLX5_ASSERT() and
> >> RTE_SET_USED() with equivalent claim_zero().
> >>
> >> Cc: stable@dpdk.org
> >>
> >> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> >> ---
> >>   drivers/net/mlx5/mlx5_txpp.c | 30 ++++++++++--------------------
> >>   1 file changed, 10 insertions(+), 20 deletions(-)
> >>
> >> diff --git a/drivers/net/mlx5/mlx5_txpp.c
> >> b/drivers/net/mlx5/mlx5_txpp.c index 73626f0e8f..af77e91e4c 100644
> >> --- a/drivers/net/mlx5/mlx5_txpp.c
> >> +++ b/drivers/net/mlx5/mlx5_txpp.c
> >> @@ -890,7 +890,6 @@ mlx5_txpp_start(struct rte_eth_dev *dev)
> >>   	struct mlx5_priv *priv = dev->data->dev_private;
> >>   	struct mlx5_dev_ctx_shared *sh = priv->sh;
> >>   	int err = 0;
> >> -	int ret;
> >>
> >>   	if (!priv->config.tx_pp) {
> >>   		/* Packet pacing is not requested for the device. */ @@ -
> >> 903,14 +902,14 @@ mlx5_txpp_start(struct rte_eth_dev *dev)
> >>   		return 0;
> >>   	}
> >>   	if (priv->config.tx_pp > 0) {
> >> -		ret = rte_mbuf_dynflag_lookup
> >> -
> >> 	(RTE_MBUF_DYNFLAG_TX_TIMESTAMP_NAME, NULL);
> >> -		if (ret < 0)
> >> +		err = rte_mbuf_dynflag_lookup
> >> +			(RTE_MBUF_DYNFLAG_TX_TIMESTAMP_NAME,
> >> NULL);
> >> +		/* No flag registered means no service needed. */
> >> +		if (err < 0)
> >>   			return 0;
> >> +		err = 0;
> >>   	}
> >> -	ret = pthread_mutex_lock(&sh->txpp.mutex);
> >> -	MLX5_ASSERT(!ret);
> >> -	RTE_SET_USED(ret);
> >> +	claim_zero(pthread_mutex_lock(&sh->txpp.mutex));
> >>   	if (sh->txpp.refcnt) {
> >>   		priv->txpp_en = 1;
> >>   		++sh->txpp.refcnt;
> >> @@ -924,9 +923,7 @@ mlx5_txpp_start(struct rte_eth_dev *dev)
> >>   			rte_errno = -err;
> >>   		}
> >>   	}
> >> -	ret = pthread_mutex_unlock(&sh->txpp.mutex);
> >> -	MLX5_ASSERT(!ret);
> >> -	RTE_SET_USED(ret);
> >> +	claim_zero(pthread_mutex_unlock(&sh->txpp.mutex));
> >>   	return err;
> >>   }
> >>
> >> @@ -944,28 +941,21 @@ mlx5_txpp_stop(struct rte_eth_dev *dev)  {
> >>   	struct mlx5_priv *priv = dev->data->dev_private;
> >>   	struct mlx5_dev_ctx_shared *sh = priv->sh;
> >> -	int ret;
> >>
> >>   	if (!priv->txpp_en) {
> >>   		/* Packet pacing is already disabled for the device. */
> >>   		return;
> >>   	}
> >>   	priv->txpp_en = 0;
> >> -	ret = pthread_mutex_lock(&sh->txpp.mutex);
> >> -	MLX5_ASSERT(!ret);
> >> -	RTE_SET_USED(ret);
> >> +	claim_zero(pthread_mutex_lock(&sh->txpp.mutex));
> >>   	MLX5_ASSERT(sh->txpp.refcnt);
> >>   	if (!sh->txpp.refcnt || --sh->txpp.refcnt) {
> >> -		ret = pthread_mutex_unlock(&sh->txpp.mutex);
> >> -		MLX5_ASSERT(!ret);
> >> -		RTE_SET_USED(ret);
> >> +		claim_zero(pthread_mutex_unlock(&sh->txpp.mutex));
> >>   		return;
> >>   	}
> >>   	/* No references any more, do actual destroy. */
> >>   	mlx5_txpp_destroy(sh);
> >> -	ret = pthread_mutex_unlock(&sh->txpp.mutex);
> >> -	MLX5_ASSERT(!ret);
> >> -	RTE_SET_USED(ret);
> >> +	claim_zero(pthread_mutex_unlock(&sh->txpp.mutex));
> >>   }
> >>
> >>   /*
> >> --
> >> 2.18.1
> >