Re: [PATCH rdma-next v1 1/4] IB/mlx5: Introduce ODP diagnostic counters

[Jason Gunthorpe <jgg@mellanox.com>]

On Fri, Aug 30, 2019 at 11:16:09AM +0300, Leon Romanovsky wrote:
> From: Erez Alfasi <ereza@mellanox.com>
> 
> Introduce ODP diagnostic counters and count the following
> per MR within IB/mlx5 driver:
>  1) Page faults:
> 	Total number of faulted pages.
>  2) Page invalidations:
> 	Total number of pages invalidated by the OS during all
> 	invalidation events. The translations can be no longer
> 	valid due to either non-present pages or mapping changes.
>  3) Prefetched pages:
> 	When prefetching a page, page fault is generated
> 	in order to bring the page to the main memory.
> 	The prefetched pages counter will be updated
> 	during a page fault flow only if it was derived
> 	from prefetching operation.
> 
> Signed-off-by: Erez Alfasi <ereza@mellanox.com>
> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
>  drivers/infiniband/hw/mlx5/odp.c | 18 ++++++++++++++++++
>  include/rdma/ib_umem_odp.h       | 14 ++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
> index 905936423a03..b7c8a49ac753 100644
> +++ b/drivers/infiniband/hw/mlx5/odp.c
> @@ -287,6 +287,10 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
>  
>  	ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
>  
> +	/* Count page invalidations */
> +	ib_update_odp_stats(umem_odp, invalidations,
> +			    ib_umem_odp_num_pages(umem_odp));

This doesn't seem right, it should only count the number of pages that
were actually removed from the mapping

> diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h
> index b37c674b7fe6..3359e34516da 100644
> +++ b/include/rdma/ib_umem_odp.h
> @@ -37,6 +37,12 @@
>  #include <rdma/ib_verbs.h>
>  #include <linux/interval_tree.h>
>  
> +struct ib_odp_counters {
> +	atomic64_t faults;
> +	atomic64_t invalidations;
> +	atomic64_t prefetched;
> +};
> +
>  struct ib_umem_odp {
>  	struct ib_umem umem;
>  	struct ib_ucontext_per_mm *per_mm;
> @@ -62,6 +68,11 @@ struct ib_umem_odp {
>  	struct mutex		umem_mutex;
>  	void			*private; /* for the HW driver to use. */
>  
> +	/*
> +	 * ODP diagnostic counters.
> +	 */
> +	struct ib_odp_counters odp_stats;

This really belongs in the MR not the umem

>  	int notifiers_seq;
>  	int notifiers_count;
>  	int npages;
> @@ -106,6 +117,9 @@ static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
>  	       umem_odp->page_shift;
>  }
>  
> +#define ib_update_odp_stats(umem_odp, counter_name, value)		    \
> +	atomic64_add(value, &(umem_odp->odp_stats.counter_name))

Missing brackets in a macro

Jason