From: Michel Lespinasse <walken@xxxxxxxxxx> Subject: augmented rbtree: rework the RB_DECLARE_CALLBACKS macro definition Change the definition of the RBCOMPUTE function. The propagate callback repeatedly calls RBCOMPUTE as it moves from leaf to root. it wants to stop recomputing once the augmented subtree information doesn't change. This was previously checked using the == operator, but that only works when the augmented subtree information is a scalar field. This commit modifies the RBCOMPUTE function so that it now sets the augmented subtree information instead of returning it, and returns a boolean value indicating if the propagate callback should stop. The motivation for this change is that I want to introduce augmented rbtree uses where the augmented data for the subtree is a struct instead of a scalar. Link: http://lkml.kernel.org/r/20190703040156.56953-4-walken@xxxxxxxxxx Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Uladzislau Rezki <urezki@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/rbtree_augmented.h | 24 +++++++++++------------ tools/include/linux/rbtree_augmented.h | 24 +++++++++++------------ 2 files changed, 24 insertions(+), 24 deletions(-) --- a/include/linux/rbtree_augmented.h~augmented-rbtree-rework-the-rb_declare_callbacks-macro-definition +++ a/include/linux/rbtree_augmented.h @@ -67,22 +67,19 @@ rb_insert_augmented_cached(struct rb_nod * 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 + * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data */ -#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ - RBTYPE, RBAUGMENTED, RBCOMPUTE) \ +#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ static inline void \ RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \ { \ while (rb != stop) { \ RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \ - RBTYPE augmented = RBCOMPUTE(node); \ - if (node->RBAUGMENTED == augmented) \ + if (RBCOMPUTE(node, true)) \ break; \ - node->RBAUGMENTED = augmented; \ rb = rb_parent(&node->RBFIELD); \ } \ } \ @@ -99,7 +96,7 @@ RBNAME ## _rotate(struct rb_node *rb_old RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ new->RBAUGMENTED = old->RBAUGMENTED; \ - old->RBAUGMENTED = RBCOMPUTE(old); \ + RBCOMPUTE(old, false); \ } \ RBSTATIC const struct rb_augment_callbacks RBNAME = { \ .propagate = RBNAME ## _propagate, \ @@ -122,7 +119,7 @@ RBSTATIC const struct rb_augment_callbac #define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ RBTYPE, RBAUGMENTED, RBCOMPUTE) \ -static inline RBTYPE RBNAME ## _compute_max(RBSTRUCT *node) \ +static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \ { \ RBSTRUCT *child; \ RBTYPE max = RBCOMPUTE(node); \ @@ -136,10 +133,13 @@ static inline RBTYPE RBNAME ## _compute_ if (child->RBAUGMENTED > max) \ max = child->RBAUGMENTED; \ } \ - return max; \ + if (exit && node->RBAUGMENTED == max) \ + return true; \ + node->RBAUGMENTED = max; \ + return false; \ } \ -RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ - RBTYPE, RBAUGMENTED, RBNAME ## _compute_max) +RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max) #define RB_RED 0 --- a/tools/include/linux/rbtree_augmented.h~augmented-rbtree-rework-the-rb_declare_callbacks-macro-definition +++ a/tools/include/linux/rbtree_augmented.h @@ -69,22 +69,19 @@ rb_insert_augmented_cached(struct rb_nod * 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 + * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data */ -#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ - RBTYPE, RBAUGMENTED, RBCOMPUTE) \ +#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ static inline void \ RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \ { \ while (rb != stop) { \ RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \ - RBTYPE augmented = RBCOMPUTE(node); \ - if (node->RBAUGMENTED == augmented) \ + if (RBCOMPUTE(node, true)) \ break; \ - node->RBAUGMENTED = augmented; \ rb = rb_parent(&node->RBFIELD); \ } \ } \ @@ -101,7 +98,7 @@ RBNAME ## _rotate(struct rb_node *rb_old RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ new->RBAUGMENTED = old->RBAUGMENTED; \ - old->RBAUGMENTED = RBCOMPUTE(old); \ + RBCOMPUTE(old, false); \ } \ RBSTATIC const struct rb_augment_callbacks RBNAME = { \ .propagate = RBNAME ## _propagate, \ @@ -124,7 +121,7 @@ RBSTATIC const struct rb_augment_callbac #define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ RBTYPE, RBAUGMENTED, RBCOMPUTE) \ -static inline RBTYPE RBNAME ## _compute_max(RBSTRUCT *node) \ +static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \ { \ RBSTRUCT *child; \ RBTYPE max = RBCOMPUTE(node); \ @@ -138,10 +135,13 @@ static inline RBTYPE RBNAME ## _compute_ if (child->RBAUGMENTED > max) \ max = child->RBAUGMENTED; \ } \ - return max; \ + if (exit && node->RBAUGMENTED == max) \ + return true; \ + node->RBAUGMENTED = max; \ + return false; \ } \ -RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ - RBTYPE, RBAUGMENTED, RBNAME ## _compute_max) +RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max) #define RB_RED 0 _
