On Tue, Dec 26, 2017 at 07:54:40PM +0300, Kirill A. Shutemov wrote: > On Fri, Dec 15, 2017 at 02:03:35PM -0800, Matthew Wilcox wrote: > > From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> > > > > This results in no change in structure size on 64-bit x86 as it fits in > > the padding between the gfp_t and the void *. > > The patch does more than described in the subject and commit message. At first > I was confused why do you need to touch idr here. It took few minutes to figure > it out. > > Could you please add more into commit message about lockname and xa_ locking > interface since you introduce it here? Sure! How's this? xarray: Add the xa_lock to the radix_tree_root This results in no change in structure size on 64-bit x86 as it fits in the padding between the gfp_t and the void *. Initialising the spinlock requires a name for the benefit of lockdep, so RADIX_TREE_INIT() now needs to know the name of the radix tree it's initialising, and so do IDR_INIT() and IDA_INIT(). Also add the xa_lock() and xa_unlock() family of wrappers to make it easier to use the lock. If we could rely on -fplan9-extensions in the compiler, we could avoid all of this syntactic sugar, but that wasn't added until gcc 4.6. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>