On Thu, May 21, 2020 at 08:38:35PM +0800, Muchun Song wrote: > There is another safe way to get the file structure without > holding the files->file_lock. That is rcu lock, and this way > has better performance. So use the rcu lock instead of the > files->file_lock. What makes you think this is safe? Are you actually seeing contention on this spinlock?