From f6bb2a2c0b81c47282ddb7883f92e65a063c27dd Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 10 Apr 2018 16:36:52 -0700 Subject: xarray: add the xa_lock to the radix_tree_root This results in no change in structure size on 64-bit machines as it fits in the padding between the gfp_t and the void *. 32-bit machines will grow the structure from 8 to 12 bytes. Almost all radix trees are protected with (at least) a spinlock, so as they are converted from radix trees to xarrays, the data structures will shrink again. 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. Link: http://lkml.kernel.org/r/20180313132639.17387-8-willy@infradead.org Signed-off-by: Matthew Wilcox Reviewed-by: Jeff Layton Cc: Darrick J. Wong Cc: Dave Chinner Cc: Ryusuke Konishi Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/idr.h | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'include/linux/idr.h') diff --git a/include/linux/idr.h b/include/linux/idr.h index 913c335054f0..e856f4e0ab35 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -32,27 +32,28 @@ struct idr { #define IDR_RT_MARKER (ROOT_IS_IDR | (__force gfp_t) \ (1 << (ROOT_TAG_SHIFT + IDR_FREE))) -#define IDR_INIT_BASE(base) { \ - .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER), \ +#define IDR_INIT_BASE(name, base) { \ + .idr_rt = RADIX_TREE_INIT(name, IDR_RT_MARKER), \ .idr_base = (base), \ .idr_next = 0, \ } /** * IDR_INIT() - Initialise an IDR. + * @name: Name of IDR. * * A freshly-initialised IDR contains no IDs. */ -#define IDR_INIT IDR_INIT_BASE(0) +#define IDR_INIT(name) IDR_INIT_BASE(name, 0) /** - * DEFINE_IDR() - Define a statically-allocated IDR - * @name: Name of IDR + * DEFINE_IDR() - Define a statically-allocated IDR. + * @name: Name of IDR. * * An IDR defined using this macro is ready for use with no additional * initialisation required. It contains no IDs. */ -#define DEFINE_IDR(name) struct idr name = IDR_INIT +#define DEFINE_IDR(name) struct idr name = IDR_INIT(name) /** * idr_get_cursor - Return the current position of the cyclic allocator @@ -219,10 +220,10 @@ struct ida { struct radix_tree_root ida_rt; }; -#define IDA_INIT { \ - .ida_rt = RADIX_TREE_INIT(IDR_RT_MARKER | GFP_NOWAIT), \ +#define IDA_INIT(name) { \ + .ida_rt = RADIX_TREE_INIT(name, IDR_RT_MARKER | GFP_NOWAIT), \ } -#define DEFINE_IDA(name) struct ida name = IDA_INIT +#define DEFINE_IDA(name) struct ida name = IDA_INIT(name) int ida_pre_get(struct ida *ida, gfp_t gfp_mask); int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); -- cgit v1.2.3