On Tue, 14 Apr 2020, Michel Lespinasse wrote:
This change wraps the existing mmap_sem related rwsem calls into a new
mmap locking API. There are two justifications for the new API:
- At first, it provides an easy hooking point to instrument mmap_sem
locking latencies independently of any other rwsems.
- In the future, it may be a starting point for replacing the rwsem
implementation with a different one, such as range locks.
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dbueso@xxxxxxx>
With one observation below.
+static inline void mmap_downgrade_write_lock(struct mm_struct *mm)
+{
+ downgrade_write(&mm->mmap_sem);
+}
Shouldn't this really be just mmap_downgrade_write()? In locking
normally don't add the _lock at the end as it implies the operation
of acquiring the lock.
Thanks,
Davidlohr
