diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-06 20:15:42 -0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-20 09:35:02 -0300 |
| commit | c7d8b7824ff9de866a356e1892dbe9f191aa5d06 (patch) | |
| tree | a0e5a54cc6d3647bbcfcefb7aa72522a130e68d8 /include/linux/hmm.h | |
| parent | e4c057d02c9ef0b39bb88544b0c3c0a0a4d55ed6 (diff) | |
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 'include/linux/hmm.h')
| -rw-r--r-- | include/linux/hmm.h | 12 |
1 files changed, 1 insertions, 11 deletions
diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 51e18fbb8953..3fec513b9c00 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -84,15 +84,12 @@ * @notifiers: count of active mmu notifiers */ struct hmm { - struct mm_struct *mm; - struct kref kref; + struct mmu_notifier mmu_notifier; spinlock_t ranges_lock; struct list_head ranges; struct list_head mirrors; - struct mmu_notifier mmu_notifier; struct rw_semaphore mirrors_sem; wait_queue_head_t wq; - struct rcu_head rcu; long notifiers; }; @@ -409,13 +406,6 @@ long hmm_range_dma_unmap(struct hmm_range *range, */ #define HMM_RANGE_DEFAULT_TIMEOUT 1000 -/* Below are for HMM internal use only! Not to be used by device driver! */ -static inline void hmm_mm_init(struct mm_struct *mm) -{ - mm->hmm = NULL; -} -#else /* IS_ENABLED(CONFIG_HMM_MIRROR) */ -static inline void hmm_mm_init(struct mm_struct *mm) {} #endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */ #endif /* LINUX_HMM_H */ |