path: root/arch
diff options
authorMatthew Wilcox <>2016-05-20 17:03:54 -0700
committerLinus Torvalds <>2016-05-20 17:58:30 -0700
commit3bcadd6fa6c4fd07ace3626357c824eb532488a6 (patch)
tree4e0fee97bdc25e76f7a786e1049a9aab6208d518 /arch
parent78a9be0a0a3367b94af242632c525d22b26f1a87 (diff)
radix-tree: free up the bottom bit of exceptional entries for reuse
We are guaranteed that pointers to radix_tree_nodes always have the bottom two bits clear (because they come from a slab cache, and slab caches have a minimum alignment of sizeof(void *)), so we can redefine 'radix_tree_is_internal_node' to only return true if the bottom two bits have value '01'. This frees up one quarter of the potential values for use by the user. Idea from Neil Brown. Signed-off-by: Matthew Wilcox <> Suggested-by: Neil Brown <> Cc: Konstantin Khlebnikov <> Cc: Kirill Shutemov <> Cc: Jan Kara <> Cc: Ross Zwisler <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions