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author | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-21 14:10:36 -0300 |
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committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-21 14:10:36 -0300 |
commit | 868df536f5e84672c3e002b949e0e44f97cb0f09 (patch) | |
tree | f76da5f6d06125b6d91c75ebfe4079ec9e2f958a /mm/hugetlb.c | |
parent | b2299e83815c59ab59c4ee4fb4842b3b28e5072f (diff) | |
parent | fba0e448a2c5b297a4ddc1ec4e48f4aa6600a1c9 (diff) | |
download | linux-868df536f5e84672c3e002b949e0e44f97cb0f09.tar.bz2 |
Merge branch 'odp_fixes' into rdma.git for-next
Jason Gunthorpe says:
====================
This is a collection of general cleanups for ODP to clarify some of the
flows around umem creation and use of the interval tree.
====================
The branch is based on v5.3-rc5 due to dependencies
* odp_fixes:
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
RDMA/core: Make invalidate_range a device operation
RDMA/odp: Use kvcalloc for the dma_list and page_list
RDMA/odp: Check for overflow when computing the umem_odp end
RDMA/odp: Provide ib_umem_odp_release() to undo the allocs
RDMA/odp: Split creating a umem_odp from ib_umem_get
RDMA/odp: Make the three ways to create a umem_odp clear
RMDA/odp: Consolidate umem_odp initialization
RDMA/odp: Make it clearer when a umem is an implicit ODP umem
RDMA/odp: Iterate over the whole rbtree directly
RDMA/odp: Use the common interval tree library instead of generic
RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r-- | mm/hugetlb.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index ede7e7f5d1ab..6d7296dd11b8 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3856,6 +3856,25 @@ retry: page = alloc_huge_page(vma, haddr, 0); if (IS_ERR(page)) { + /* + * Returning error will result in faulting task being + * sent SIGBUS. The hugetlb fault mutex prevents two + * tasks from racing to fault in the same page which + * could result in false unable to allocate errors. + * Page migration does not take the fault mutex, but + * does a clear then write of pte's under page table + * lock. Page fault code could race with migration, + * notice the clear pte and try to allocate a page + * here. Before returning error, get ptl and make + * sure there really is no pte entry. + */ + ptl = huge_pte_lock(h, mm, ptep); + if (!huge_pte_none(huge_ptep_get(ptep))) { + ret = 0; + spin_unlock(ptl); + goto out; + } + spin_unlock(ptl); ret = vmf_error(PTR_ERR(page)); goto out; } |