On Fri, Jul 26, 2013 at 02:13:38PM -0700, Cody P Schafer wrote: > Postorder iteration yields all of a node's children prior to yielding the node > itself, and this particular implementation also avoids examining the leaf links > in a node after that node has been yielded. > > In what I expect will be it's most common usage, postorder iteration allows the s/it's/its/ > deletion of every node in an rbtree without modifying the rbtree nodes (no > _requirement_ that they be nulled) while avoiding referencing child nodes after > they have been "deleted" (most commonly, freed). > > I have only updated zswap to use this functionality at this point, but numerous > bits of code (most notably in the filesystem drivers) use a hand rolled > postorder iteration that NULLs child links as it traverses the tree. Each of > those instances could be replaced with this common implementation. Thanks for doing this Cody! Other than the nits I've sent, it looks good. Whole set: Reviewed-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx> > > Cody P Schafer (5): > rbtree: add postorder iteration functions. > rbtree: add rbtree_postorder_for_each_entry_safe() helper. > rbtree_test: add test for postorder iteration. > rbtree: allow tests to run as builtin > mm/zswap: use postorder iteration when destroying rbtree > > include/linux/rbtree.h | 21 +++++++++++++++++++++ > lib/Kconfig.debug | 2 +- > lib/rbtree.c | 40 ++++++++++++++++++++++++++++++++++++++++ > lib/rbtree_test.c | 12 ++++++++++++ > mm/zswap.c | 15 ++------------- > 5 files changed, 76 insertions(+), 14 deletions(-) > > -- > 1.8.3.4 > -- 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>