On Tue, Dec 18, 2018 at 05:39:30PM +0000, Jason Gunthorpe wrote:
> On Tue, Dec 18, 2018 at 02:15:56PM +0200, Leon Romanovsky wrote:
> > From: Huy Nguyen <huyn@xxxxxxxxxxxx>
> >
> > On NVMe offloads connection with many IO queues, EEH takes long time to
> > recover. The culprit is the synchronize_srcu in the destroy_mkey. Solution
> > is to use synchronize_srcu only for ODP mkey.
> >
> > Fixes: b4cfe447d47b ("IB/mlx5: Implement on demand paging by adding support for MMU notifiers")
> > Signed-off-by: Huy Nguyen <huyn@xxxxxxxxxxxx>
> > Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
> > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> > drivers/infiniband/hw/mlx5/mr.c | 19 ++++++++++++++++---
> > 1 file changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
> > index d45a9163c198..0f01059724e9 100644
> > +++ b/drivers/infiniband/hw/mlx5/mr.c
> > @@ -73,7 +73,8 @@ static int destroy_mkey(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
> >
> > #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
> > /* Wait until all page fault handlers using the mr complete. */
> > - synchronize_srcu(&dev->mr_srcu);
> > + if (mr->umem && mr->umem->is_odp)
> > + synchronize_srcu(&dev->mr_srcu);
> > #endif
>
> We don't need any of these gross #ifdef's..
>
> Add a
>
> static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
> {
> return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem && mr->umem->is_odp;
> }
>
> And use it in place of all the is_odp tests.
>
> Since it returns the constant false if ODP is disabled the compiler
> will drop all the branches naturally without the horrible #ifdef mess.
>
> Someone should send a cleanup patch for ODP to get rid of more
> #ifdefs.
Jason,
Let's take this patch as is and I'll clean ODP code after that in one shot.
Thanks
>
> Jason
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