Re: [PATCH] IB/mlx5: avoid binding a new mpi unit to the same devices repeatedly

[Qing Huang]

Hi Daniel,


On 7/23/2018 11:11 AM, Daniel Jurgens wrote:
> On 7/23/2018 10:36 AM, Qing Huang wrote:
> > Hi Daniel/Parav,
> >
> > Have you got a chance to review this patch? Thanks!
> Hi Qing, sorry for the delay, I just got back to the office today. I don't agree with the proposed fix, I provided an alternative suggestion below.
> > > > Or.
> > > >
> > > > > Reported-by: Gerald Gibson <gerald.gibson@xxxxxxxxxx>
> > > > > Signed-off-by: Qing Huang <qing.huang@xxxxxxxxxx>
> > > > > ---
> > > > >  Â drivers/infiniband/hw/mlx5/main.c | 3 ++-
> > > > >  Â 1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> > > > > index b3ba9a2..1ddd1d3 100644
> > > > > --- a/drivers/infiniband/hw/mlx5/main.c
> > > > > +++ b/drivers/infiniband/hw/mlx5/main.c
> > > > > @@ -6068,7 +6068,8 @@ static void *mlx5_ib_add_slave_port(struct mlx5_core_dev *mdev, u8 port_num)
> > > > >
> > > > >  ÂÂÂÂÂÂÂÂ mutex_lock(&mlx5_ib_multiport_mutex);
> > > > >  ÂÂÂÂÂÂÂÂ list_for_each_entry(dev, &mlx5_ib_dev_list, ib_dev_list) {
> > > > > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ if (dev->sys_image_guid == mpi->sys_image_guid)
> > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ if (dev->sys_image_guid == mpi->sys_image_guid &&
> > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ !dev->port[mlx5_core_native_port_num(mdev) - 1].mp.mpi)
> You shouldn't check the mpi field that without holding the lock in the mp structure. Prefer you change the print from a warning in mlx5_ib_bind_slave_port to a debug message.
Thanks for the review. That works for us too. Will resend the patch.

Regards,
Qing

> > > > >  ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ bound = mlx5_ib_bind_slave_port(dev, mpi);
> > > > >
> > > > >  ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ if (bound) {
> > > > > --
> > > > > 2.9.3
> > > > >
> > > > > --
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