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| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-10-09 19:09:29 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-10-28 22:41:14 +0300 |
| commit | 423f52d65005e8f5067d94bd4f41d8a7d8388135 (patch) | |
| tree | e98ea824d6b8dd6cccc3571f9d03bdcc420c163d /include/rdma | |
| parent | 54375e7382952daded7002d1618eadaae859cecb (diff) | |
| download | linux-423f52d65005e8f5067d94bd4f41d8a7d8388135.tar.xz | |
RDMA/mlx5: Use an xarray for the children of an implicit ODP
Currently the child leaves are stored in the shared interval tree and
every lookup for a child must be done under the interval tree rwsem.
This is further complicated by dropping the rwsem during iteration (ie the
odp_lookup(), odp_next() pattern), which requires a very tricky an
difficult to understand locking scheme with SRCU.
Instead reserve the interval tree for the exclusive use of the mmu
notifier related code in umem_odp.c and give each implicit MR a xarray
containing all the child MRs.
Since the size of each child is 1GB of VA, a 1 level xarray will index 64G
of VA, and a 2 level will index 2TB, making xarray a much better
data structure choice than an interval tree.
The locking properties of xarray will be used in the next patches to
rework the implicit ODP locking scheme into something simpler.
At this point, the xarray is locked by the implicit MR's umem_mutex, and
read can also be locked by the odp_srcu.
Link: https://lore.kernel.org/r/20191009160934.3143-10-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'include/rdma')
| -rw-r--r-- | include/rdma/ib_umem_odp.h | 16 |
1 files changed, 0 insertions, 16 deletions
diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h index 253df1a1fa54..28078efc3833 100644 --- a/include/rdma/ib_umem_odp.h +++ b/include/rdma/ib_umem_odp.h @@ -156,22 +156,6 @@ int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root, umem_call_back cb, bool blockable, void *cookie); -/* - * Find first region intersecting with address range. - * Return NULL if not found - */ -static inline struct ib_umem_odp * -rbt_ib_umem_lookup(struct rb_root_cached *root, u64 addr, u64 length) -{ - struct interval_tree_node *node; - - node = interval_tree_iter_first(root, addr, addr + length - 1); - if (!node) - return NULL; - return container_of(node, struct ib_umem_odp, interval_tree); - -} - static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp, unsigned long mmu_seq) { |