radix-tree: add radix_tree_split_preload()
authorMatthew Wilcox <willy@linux.intel.com>
Wed, 14 Dec 2016 23:09:04 +0000 (15:09 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 15 Dec 2016 00:04:10 +0000 (16:04 -0800)
commit2791653a6814d170fa893344618563a7b1da95c6
tree635c8ca43b49ac15836e5d4b5786d64733661755
parente157b555945fb16ddc6cce605a1eb6b4135ea5f1
radix-tree: add radix_tree_split_preload()

Calculate how many nodes we need to allocate to split an old_order entry
into multiple entries, each of size new_order.  The test suite checks
that we allocated exactly the right number of nodes; neither too many
(checked by rtp->nr == 0), nor too few (checked by comparing
nr_allocated before and after the call to radix_tree_split()).

Link: http://lkml.kernel.org/r/1480369871-5271-60-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/radix-tree.h
lib/radix-tree.c
tools/testing/radix-tree/multiorder.c
tools/testing/radix-tree/test.h