diff options
| author | Michel Lespinasse | 2019-09-25 16:46:07 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2019-09-25 17:51:39 -0700 |
| commit | 315cc066b8ae8349a27887ad7a34e1916e9797fe (patch) | |
| tree | 3c7dba850cee3ec6991228ae425db0de78fbb252 /include/linux/rbtree_augmented.h | |
| parent | 444b8a83f1e01584ff2d53f5951d8e836c0070b5 (diff) | |
augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks
for the case where the augmented value is a scalar whose definition
follows a max(f(node)) pattern. This actually covers all present uses of
RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the
various RBCOMPUTE function definitions.
[walken@google.com: fix mm/vmalloc.c]
Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com
[walken@google.com: re-add check to check_augmented()]
Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com
Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/rbtree_augmented.h')
| -rw-r--r-- | include/linux/rbtree_augmented.h | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h index 979941600082..e5937e387e02 100644 --- a/include/linux/rbtree_augmented.h +++ b/include/linux/rbtree_augmented.h @@ -61,7 +61,7 @@ rb_insert_augmented_cached(struct rb_node *node, } /* - * Template for declaring augmented rbtree callbacks + * Template for declaring augmented rbtree callbacks (generic case) * * RBSTATIC: 'static' or empty * RBNAME: name of the rb_augment_callbacks structure @@ -107,6 +107,40 @@ RBSTATIC const struct rb_augment_callbacks RBNAME = { \ .rotate = RBNAME ## _rotate \ }; +/* + * Template for declaring augmented rbtree callbacks, + * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes. + * + * RBSTATIC: 'static' or empty + * RBNAME: name of the rb_augment_callbacks structure + * RBSTRUCT: struct type of the tree nodes + * RBFIELD: name of struct rb_node field within RBSTRUCT + * RBTYPE: type of the RBAUGMENTED field + * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree + * RBCOMPUTE: name of function that returns the per-node RBTYPE scalar + */ + +#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ + RBTYPE, RBAUGMENTED, RBCOMPUTE) \ +static inline RBTYPE RBNAME ## _compute_max(RBSTRUCT *node) \ +{ \ + RBSTRUCT *child; \ + RBTYPE max = RBCOMPUTE(node); \ + if (node->RBFIELD.rb_left) { \ + child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \ + if (child->RBAUGMENTED > max) \ + max = child->RBAUGMENTED; \ + } \ + if (node->RBFIELD.rb_right) { \ + child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \ + if (child->RBAUGMENTED > max) \ + max = child->RBAUGMENTED; \ + } \ + return max; \ +} \ +RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ + RBTYPE, RBAUGMENTED, RBNAME ## _compute_max) + #define RB_RED 0 #define RB_BLACK 1 |