From 315cc066b8ae8349a27887ad7a34e1916e9797fe Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Wed, 25 Sep 2019 16:46:07 -0700 Subject: 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 Acked-by: Peter Zijlstra (Intel) Cc: David Howells Cc: Davidlohr Bueso Cc: Uladzislau Rezki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/include/linux/rbtree_augmented.h | 36 +++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/include/linux/rbtree_augmented.h b/tools/include/linux/rbtree_augmented.h index de3a480204ba..4e8c4c76e9a2 100644 --- a/tools/include/linux/rbtree_augmented.h +++ b/tools/include/linux/rbtree_augmented.h @@ -63,7 +63,7 @@ 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 @@ -109,6 +109,40 @@ 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 -- cgit v1.2.3-59-g8ed1b