On Sun, Oct 06, 2019 at 06:51:36PM +0300, Leon Romanovsky wrote:
> From: Erez Alfasi <ereza@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 ++++
> drivers/infiniband/hw/mlx5/odp.c | 18 ++++++++++++++++++
> include/rdma/ib_verbs.h | 6 ++++++
> 3 files changed, 28 insertions(+)
>
> diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> index bf30d53d94dc..5aae05ebf64b 100644
> +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> @@ -585,6 +585,9 @@ struct mlx5_ib_dm {
> IB_ACCESS_REMOTE_READ |\
> IB_ZERO_BASED)
>
> +#define mlx5_update_odp_stats(mr, counter_name, value) \
> + atomic64_add(value, &((mr)->odp_stats.counter_name))
> +
> struct mlx5_ib_mr {
> struct ib_mr ibmr;
> void *descs;
> @@ -622,6 +625,7 @@ struct mlx5_ib_mr {
> wait_queue_head_t q_leaf_free;
> struct mlx5_async_work cb_work;
> atomic_t num_pending_prefetch;
> + struct ib_odp_counters odp_stats;
> };
>
> static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
> diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
> index 95cf0249b015..966783bfb557 100644
> +++ b/drivers/infiniband/hw/mlx5/odp.c
> @@ -261,6 +261,10 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
> blk_start_idx = idx;
> in_block = 1;
> }
> +
> + /* Count page invalidations */
> + mlx5_update_odp_stats(mr, invalidations,
> + (idx - blk_start_idx + 1));
I feel like these should be batched and the atomic done once at the
end of the routine..
> } else {
> u64 umr_offset = idx & umr_block_mask;
>
> @@ -287,6 +291,7 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
>
> ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
>
> +
> if (unlikely(!umem_odp->npages && mr->parent &&
> !umem_odp->dying)) {
> WRITE_ONCE(umem_odp->dying, 1);
> @@ -801,6 +806,19 @@ static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
> if (ret < 0)
> goto srcu_unlock;
>
> + /*
> + * When prefetching a page, page fault is generated
> + * in order to bring the page to the main memory.
> + * In the current flow, page faults are being counted.
> + * Prefetched pages counter will be updated as well
> + * only if the current page fault flow was derived
> + * from prefetching flow.
> + */
> + mlx5_update_odp_stats(mr, faults, ret);
> +
> + if (prefetch)
> + mlx5_update_odp_stats(mr, prefetched, ret);
Hm, I'm about to post a series that eliminates 'prefetch' here..
This is also not quite right for prefetch as we are doing a form of
prefetching in the mlx5_ib_mr_rdma_pfault_handler() too, although it
is less clear how to count those. Maybe this should be split to SQ/RQ
faults?
Jason
