linux/tools/testing/radix-tree
Matthew Wilcox 070c5ac274 radix-tree: fix radix_tree_range_tag_if_tagged() for multiorder entries
I had previously decided that tagging a single multiorder entry would
count as tagging 2^order entries for the purposes of 'nr_to_tag'.  I now
believe that decision to be a mistake, and it should count as a single
entry.  That's more likely to be what callers expect.

When walking back up the tree from a newly-tagged entry, the current
code assumed we were starting from the lowest level of the tree; if we
have a multiorder entry with an order at least RADIX_TREE_MAP_SHIFT in
size then we need to shift the index by 'shift' before we start walking
back up the tree, or we will end up not setting tags on higher entries,
and then mistakenly thinking that entries below a certain point in the
tree are not tagged.

If the first index we examine is a sibling entry of a tagged multiorder
entry, we were not tagging it.  We need to examine the canonical entry,
and the easiest way to do that is to use radix_tree_descend().  We then
have to skip over sibling slots when looking for the next entry in the
tree or we will end up walking back to the canonical entry.

Add several tests for radix_tree_range_tag_if_tagged().

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
..
generated radix-tree: add support for multi-order iterating 2016-05-20 17:58:30 -07:00
linux radix-tree: add test for radix_tree_locate_item() 2016-05-20 17:58:30 -07:00
.gitignore
find_next_bit.c
linux.c
main.c radix-tree: add test for radix_tree_locate_item() 2016-05-20 17:58:30 -07:00
Makefile radix tree test suite: start adding multiorder tests 2016-05-20 17:58:30 -07:00
multiorder.c radix-tree: fix radix_tree_range_tag_if_tagged() for multiorder entries 2016-05-20 17:58:30 -07:00
rcupdate.c
regression1.c
regression2.c radix tree test suite: allow testing other fan-out values 2016-05-20 17:58:30 -07:00
regression3.c radix-tree tests: add test for radix_tree_iter_next 2016-03-17 15:09:34 -07:00
regression.h radix-tree tests: add regression3 test 2016-03-17 15:09:34 -07:00
tag_check.c radix-tree: fix radix_tree_range_tag_if_tagged() for multiorder entries 2016-05-20 17:58:30 -07:00
test.c radix tree test suite: start adding multiorder tests 2016-05-20 17:58:30 -07:00
test.h radix tree test suite: start adding multiorder tests 2016-05-20 17:58:30 -07:00