Subject: Re: [PATCH mlx5-next v1] RDMA/mlx5: Cleanup the synchronize_srcu() from the ODP flow

From: Leon Romanovsky <[email-masked]>
Date: Tue, 2 Feb 2021 08:43:49 +0200

On Mon, Feb 01, 2021 at 12:03:15PM -0800, Saeed Mahameed wrote:
> On Mon, 2021-02-01 at 15:49 -0400, Jason Gunthorpe wrote:
> > On Sun, Jan 31, 2021 at 03:24:50PM +0200, Yishai Hadas wrote:
> > > On 1/29/2021 2:23 PM, Saeed Mahameed wrote:
> > > > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mr.c
> > > > > b/drivers/net/ethernet/mellanox/mlx5/core/mr.c
> > > > > index 9eb51f06d3ae..50af84e76fb6 100644
> > > > > +++ b/drivers/net/ethernet/mellanox/mlx5/core/mr.c
> > > > > @@ -56,6 +56,7 @@ int mlx5_core_create_mkey(struct
> > > > > mlx5_core_dev
> > > > > *dev,
> > > > >          mkey->size = MLX5_GET64(mkc, mkc, len);
> > > > >          mkey->key |= mlx5_idx_to_mkey(mkey_index);
> > > > >          mkey->pd = MLX5_GET(mkc, mkc, pd);
> > > > > +       init_waitqueue_head(&mkey->wait);
> > > > >
> > > > >          mlx5_core_dbg(dev, "out 0x%x, mkey 0x%x\n",
> > > > > mkey_index, mkey-
> > > > > > key);
> > > > >          return 0;
> > > > > diff --git a/include/linux/mlx5/driver.h
> > > > > b/include/linux/mlx5/driver.h
> > > > > index 4901b4fadabb..f9e7036ae5a5 100644
> > > > > +++ b/include/linux/mlx5/driver.h
> > > > > @@ -373,6 +373,8 @@ struct mlx5_core_mkey {
> > > > >          u32                     key;
> > > > >          u32                     pd;
> > > > >          u32                     type;
> > > > > +       struct wait_queue_head wait;
> > > > > +       refcount_t usecount;
> > > > mlx5_core_mkey is used everywhere in mlx5_core and we don't care
> > > > about
> > > > odp complexity, i would like to keep the core simple and
> > > > primitive as
> > > > it is today.
> > > > please keep the layer separation and find a way to manage
> > > > refcount and
> > > > wait queue in mlx5_ib driver..
> > > >
> > > The alternative could really be to come with some wrapped mlx5_ib
> > > structure
> > > that will hold 'mlx5_core_mkey' and will add those two fields.
> >
> > Yes
> >
> > struct mlx5_ib_mkey
> > {
> >    struct mlx5_core_mkey mkey;
> >    struct wait_queue_head wait;
> >    refcount_t usecount;
> > }
> >
> > struct mlx5_ib_mr/mw/devx
> > {
> >     struct mlx5_ib_mkey mkey;
> > }
> >
>
> Yep, also i have a series internally that moves mlx5_core_mkey to
> mlx5_ib, in mlx5_core we don't need it we only need the u32 key :)
>
> I will send you this series internally.

Let's first finish this patch and perform "moving" later.

Thanks