Re: [dpdk-dev] [PATCH] net/mlx5: fix port dead lock when port shutdown

["Xueming(Steven) Li" <xuemingl@mellanox.com>]

> -----Original Message-----
> From: Yongseok Koh
> Sent: Friday, May 25, 2018 2:30 AM
> To: Xueming(Steven) Li <xuemingl@mellanox.com>
> Cc: Shahaf Shuler <shahafs@mellanox.com>; dev@dpdk.org; Adrien Mazarguil <adrien.mazarguil@6wind.com>
> Subject: Re: [PATCH] net/mlx5: fix port dead lock when port shutdown
> 
> 
> > On May 24, 2018, at 8:20 AM, Xueming Li <xuemingl@mellanox.com> wrote:
> >
> > This patch add check to avoid init device MR data twcie which caused
> > priv data linked to itself in list.
> 
> A typo.
> 
> > Fixes: 974f1e7ef146 ("net/mlx5: add new memory region support")
> > Cc: yskoh@mellanox.com
> >
> > Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> > ---
> > drivers/net/mlx5/mlx5_ethdev.c | 2 ++
> > drivers/net/mlx5/mlx5_mr.c     | 1 +
> > 2 files changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/mlx5/mlx5_ethdev.c
> > b/drivers/net/mlx5/mlx5_ethdev.c index c52ec6fb7..7ffd17ff3 100644
> > --- a/drivers/net/mlx5/mlx5_ethdev.c
> > +++ b/drivers/net/mlx5/mlx5_ethdev.c
> > @@ -398,6 +398,8 @@ mlx5_dev_configure(struct rte_eth_dev *dev)
> > 	 * deadlock. If it overflows, lookup should be done by searching MR list
> > 	 * linearly, which is slow.
> > 	 */
> > +	if (priv->mr.cache.table)
> > +		return 0;
> 
> Thanks, nice catch!
> 
> Adrien submitted a fix [1] for the similar issue. Adding device to the memory event callback list is
> moved to mlx5_pci_probe() as it should be done once. So, how about moving the rest
> (mlx5_mr_btree_init()) to mlx5_pci_probe() as well? I mean, instead of adding this check, you can move
> the btree_init() above the line where Adrien moved
> LIST_INSERT_HEAD() to. You'll need to rebase on Adrien's patch and add a comment to Shahaf there's
> dependency.
> 

Adrien's patch seems resolved the dead lock issue as well :) 
Moving mlx5_mr_btree_init() not related to it, I'll start a new patch.

> 
> [1]
> net/mlx5: fix crash when configure is not called http://dpdk.org/dev/patchwork/patch/40404/
> 
> 
> Yongseok
> 
> > 	if (mlx5_mr_btree_init(&priv->mr.cache, MLX5_MR_BTREE_CACHE_N * 2,
> > 			       dev->device->numa_node)) {
> > 		/* rte_errno is already set. */
> > diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
> > index abb1f5179..08105a443 100644
> > --- a/drivers/net/mlx5/mlx5_mr.c
> > +++ b/drivers/net/mlx5/mlx5_mr.c
> > @@ -191,6 +191,7 @@ mlx5_mr_btree_init(struct mlx5_mr_btree *bt, int n, int socket)
> > 		rte_errno = EINVAL;
> > 		return -rte_errno;
> > 	}
> > +	assert(!bt->table && !bt->size);
> > 	memset(bt, 0, sizeof(*bt));
> > 	bt->table = rte_calloc_socket("B-tree table",
> > 				      n, sizeof(struct mlx5_mr_cache),
> > --
> > 2.13.3
> >