diff options
author | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-06 20:15:41 -0300 |
---|---|---|
committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-16 12:02:59 -0300 |
commit | e4c057d02c9ef0b39bb88544b0c3c0a0a4d55ed6 (patch) | |
tree | b1840936690813e3898520822b8f73cf1ce8d6b7 /drivers/misc/sgi-gru/grufile.c | |
parent | 2c7933f53f6bff7656e3324ca1a04e478bdc57c1 (diff) |
misc/sgi-gru: use mmu_notifier_get/put for struct gru_mm_struct
GRU is already using almost the same algorithm as get/put, it even
helpfully has a 10 year old comment to make this algorithm common, which
is finally happening.
There are a few differences and fixes from this conversion:
- GRU used rcu not srcu to read the hlist
- Unclear how the locking worked to prevent gru_register_mmu_notifier()
from running concurrently with gru_drop_mmu_notifier() - this version is
safe
- GRU had a release function which only set a variable without any locking
that skiped the synchronize_srcu during unregister which looks racey,
but this makes it reliable via the integrated call_srcu().
- It is unclear if the mmap_sem is actually held when
__mmu_notifier_register() was called, lockdep will now warn if this is
wrong
Link: https://lore.kernel.org/r/20190806231548.25242-5-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dimitri Sivanich <sivanich@hpe.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/misc/sgi-gru/grufile.c')
-rw-r--r-- | drivers/misc/sgi-gru/grufile.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/misc/sgi-gru/grufile.c b/drivers/misc/sgi-gru/grufile.c index a2a142ae087b..9d042310214f 100644 --- a/drivers/misc/sgi-gru/grufile.c +++ b/drivers/misc/sgi-gru/grufile.c @@ -573,6 +573,7 @@ static void __exit gru_exit(void) gru_free_tables(); misc_deregister(&gru_miscdev); gru_proc_exit(); + mmu_notifier_synchronize(); } static const struct file_operations gru_fops = { |