Re: [PATCH rdma-next 02/10] RDMA/core: Enable Relaxed Ordering in __ib_alloc_pd()

From: Leon Romanovsky <leon@kernel.org>
To: Tom Talpey <tom@talpey.com>
Cc: Doug Ledford <dledford@redhat.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Avihai Horon <avihaih@nvidia.com>,
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Subject: Re: [PATCH rdma-next 02/10] RDMA/core: Enable Relaxed Ordering in __ib_alloc_pd()
Date: Tue, 6 Apr 2021 09:28:46 +0300	[thread overview]
Message-ID: <YGv/nne+E5xXHsME@unreal> (raw)
In-Reply-To: <befc60f3-d28a-5420-b381-0f408bd7cca9@talpey.com>

On Mon, Apr 05, 2021 at 02:01:16PM -0400, Tom Talpey wrote:
> On 4/5/2021 1:23 AM, Leon Romanovsky wrote:
> > From: Avihai Horon <avihaih@nvidia.com>
> > 
> > Enable Relaxed Ordering in __ib_alloc_pd() allocation of the
> > local_dma_lkey.
> > 
> > This will take effect only for devices that don't pre-allocate the lkey
> > but allocate it per PD allocation.
> > 
> > Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> > Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
> > Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> > ---
> >   drivers/infiniband/core/verbs.c              | 3 ++-
> >   drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c | 1 +
> >   2 files changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
> > index a1782f8a6ca0..9b719f7d6fd5 100644
> > --- a/drivers/infiniband/core/verbs.c
> > +++ b/drivers/infiniband/core/verbs.c
> > @@ -287,7 +287,8 @@ struct ib_pd *__ib_alloc_pd(struct ib_device *device, unsigned int flags,
> >   	if (device->attrs.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
> >   		pd->local_dma_lkey = device->local_dma_lkey;
> >   	else
> > -		mr_access_flags |= IB_ACCESS_LOCAL_WRITE;
> > +		mr_access_flags |=
> > +			IB_ACCESS_LOCAL_WRITE | IB_ACCESS_RELAXED_ORDERING;
> 
> So, do local_dma_lkey's get relaxed ordering unconditionally?

Yes, in mlx5, this lkey is created on the fly.

Thanks