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| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-11-12 16:22:22 -0400 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-11-23 19:56:44 -0400 |
| commit | f25a546e65292b36f15cca0912450c4944fae031 (patch) | |
| tree | 045faece87dbe0b3294db953432c84221a620b50 /drivers/infiniband/hw/mlx5/mr.c | |
| parent | 107e899874e95dcddc779142942bf285eba38bc5 (diff) | |
| download | kernel_replicant_linux-f25a546e65292b36f15cca0912450c4944fae031.tar.gz kernel_replicant_linux-f25a546e65292b36f15cca0912450c4944fae031.tar.bz2 kernel_replicant_linux-f25a546e65292b36f15cca0912450c4944fae031.zip | |
RDMA/odp: Use mmu_interval_notifier_insert()
Replace the internal interval tree based mmu notifier with the new common
mmu_interval_notifier_insert() API. This removes a lot of code and fixes a
deadlock that can be triggered in ODP:
zap_page_range()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem)
unmap_single_vma()
[..]
__split_huge_page_pmd()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem) // DEADLOCK
mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)
mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)
The umem_rwsem is held across the range_start/end as the ODP algorithm for
invalidate_range_end cannot tolerate changes to the interval
tree. However, due to the nested invalidation regions the second
down_read() can deadlock if there are competing writers. The new core code
provides an alternative scheme to solve this problem.
Fixes: ca748c39ea3f ("RDMA/umem: Get rid of per_mm->notifier_count")
Link: https://lore.kernel.org/r/20191112202231.3856-6-jgg@ziepe.ca
Tested-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/mlx5/mr.c')
| -rw-r--r-- | drivers/infiniband/hw/mlx5/mr.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 199f7959aaa5..fbe31830b228 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -743,7 +743,8 @@ static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata, if (access_flags & IB_ACCESS_ON_DEMAND) { struct ib_umem_odp *odp; - odp = ib_umem_odp_get(udata, start, length, access_flags); + odp = ib_umem_odp_get(udata, start, length, access_flags, + &mlx5_mn_ops); if (IS_ERR(odp)) { mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(odp)); |