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| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-07 01:15:42 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-20 14:35:02 +0200 |
| commit | c7d8b7824ff9de866a356e1892dbe9f191aa5d06 (patch) | |
| tree | a0e5a54cc6d3647bbcfcefb7aa72522a130e68d8 /kernel/fork.c | |
| parent | misc/sgi-gru: use mmu_notifier_get/put for struct gru_mm_struct (diff) | |
| download | linux-c7d8b7824ff9de866a356e1892dbe9f191aa5d06.tar.xz linux-c7d8b7824ff9de866a356e1892dbe9f191aa5d06.zip | |
hmm: use mmu_notifier_get/put for 'struct hmm'
This is a significant simplification, it eliminates all the remaining
'hmm' stuff in mm_struct, eliminates krefing along the critical notifier
paths, and takes away all the ugly locking and abuse of page_table_lock.
mmu_notifier_get() provides the single struct hmm per struct mm which
eliminates mm->hmm.
It also directly guarantees that no mmu_notifier op callback is callable
while concurrent free is possible, this eliminates all the krefs inside
the mmu_notifier callbacks.
The remaining krefs in the range code were overly cautious, drivers are
already not permitted to free the mirror while a range exists.
Link: https://lore.kernel.org/r/20190806231548.25242-6-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index d8ae0f1b4148..bd4a0762f12f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1007,7 +1007,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_owner(mm, p); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_mm_init(mm); - hmm_mm_init(mm); init_tlb_flush_pending(mm); #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS mm->pmd_huge_pte = NULL; |