Date: Wed, 10 Jun 2020 00:55:14 +0200 From: Mateusz Guzik <mjguzik@gmail.com> To: Doug Moore <dougm@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r361984 - in head/sys: compat/linuxkpi/common/include/linux sys Message-ID: <CAGudoHF8bDuxQ8CS%2Bezq9B9Ro=XYopJHNmAjiZsR7ftJBfO8VA@mail.gmail.com> In-Reply-To: <202006092019.059KJCLG039099@repo.freebsd.org> References: <202006092019.059KJCLG039099@repo.freebsd.org>
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This broke lint kernels as they define DIAGNOSTIC and fail in kern/subr_stat.c:
/usr/src/sys/kern/subr_stats.c:3384:9: error: implicit declaration of
function 'RB_COLOR' is invalid in C99
[-Werror,-Wimplicit-function-declaration]
RB_COLOR(rbctd64, rblnk),
^
/usr/src/sys/kern/subr_stats.c:3384:27: error: use of undeclared
identifier 'rblnk'
RB_COLOR(rbctd64, rblnk),
On 6/9/20, Doug Moore <dougm@freebsd.org> wrote:
> Author: dougm
> Date: Tue Jun 9 20:19:11 2020
> New Revision: 361984
> URL: https://svnweb.freebsd.org/changeset/base/361984
>
> Log:
> To reduce the size of an rb_node, drop the color field. Set the least
> significant bit in the pointer to the node from its parent to indicate
> that the node is red. Have the tree rotation macros leave the
> old-parent/new-child node red and the new-parent/old-child node black.
>
> This change makes RB_LEFT and RB_RIGHT no longer assignable, and
> RB_COLOR no longer defined. Any code that modifies the tree or
> examines a node color would have to be modified after this change.
>
> Reviewed by: markj
> Tested by: pho
> Differential Revision: https://reviews.freebsd.org/D25105
>
> Modified:
> head/sys/compat/linuxkpi/common/include/linux/rbtree.h
> head/sys/sys/tree.h
>
> Modified: head/sys/compat/linuxkpi/common/include/linux/rbtree.h
> ==============================================================================
> --- head/sys/compat/linuxkpi/common/include/linux/rbtree.h Tue Jun 9
> 19:16:49 2020 (r361983)
> +++ head/sys/compat/linuxkpi/common/include/linux/rbtree.h Tue Jun 9
> 20:19:11 2020 (r361984)
> @@ -57,11 +57,7 @@ RB_HEAD(linux_root, rb_node);
> RB_PROTOTYPE(linux_root, rb_node, __entry, panic_cmp);
>
> #define rb_parent(r) RB_PARENT(r, __entry)
> -#define rb_color(r) RB_COLOR(r, __entry)
> -#define rb_is_red(r) (rb_color(r) == RB_RED)
> -#define rb_is_black(r) (rb_color(r) == RB_BLACK)
> #define rb_set_parent(r, p) rb_parent((r)) = (p)
> -#define rb_set_color(r, c) rb_color((r)) = (c)
> #define rb_entry(ptr, type, member) container_of(ptr, type, member)
>
> #define RB_EMPTY_ROOT(root) RB_EMPTY((struct linux_root *)root)
> @@ -82,7 +78,6 @@ rb_link_node(struct rb_node *node, struct rb_node *par
> struct rb_node **rb_link)
> {
> rb_set_parent(node, parent);
> - rb_set_color(node, RB_RED);
> node->__entry.rbe_left = node->__entry.rbe_right = NULL;
> *rb_link = node;
> }
>
> Modified: head/sys/sys/tree.h
> ==============================================================================
> --- head/sys/sys/tree.h Tue Jun 9 19:16:49 2020 (r361983)
> +++ head/sys/sys/tree.h Tue Jun 9 20:19:11 2020 (r361984)
> @@ -307,35 +307,32 @@ struct name { \
> (root)->rbh_root = NULL; \
> } while (/*CONSTCOND*/ 0)
>
> -#define RB_BLACK 0
> -#define RB_RED 1
> #define RB_ENTRY(type) \
> struct { \
> struct type *rbe_left; /* left element */ \
> struct type *rbe_right; /* right element */ \
> struct type *rbe_parent; /* parent element */ \
> - int rbe_color; /* node color */ \
> }
>
> -#define RB_LEFT(elm, field) (elm)->field.rbe_left
> -#define RB_RIGHT(elm, field) (elm)->field.rbe_right
> +#define RB_LF(elm, field) (elm)->field.rbe_left
> +#define RB_RT(elm, field) (elm)->field.rbe_right
> +#define RB_FLIP(elm) (*(__uintptr_t *)&(elm) ^= 1)
> +#define RB_FLIP_LF(elm, field) RB_FLIP(RB_LF(elm, field))
> +#define RB_FLIP_RT(elm, field) RB_FLIP(RB_RT(elm, field))
> +#define RB_ISRED(elm) ((*(__uintptr_t *)&(elm) & 1) != 0)
> +#define RB_RED_LF(elm, field) RB_ISRED(RB_LF(elm, field))
> +#define RB_RED_RT(elm, field) RB_ISRED(RB_RT(elm, field))
> +#define RB_PTR(elm, field) ((__typeof(elm->field.rbe_parent)) \
> + ((__uintptr_t)(elm) & ~(__uintptr_t)1))
> +#define RB_LEFT(elm, field) RB_PTR(RB_LF(elm, field), field)
> +#define RB_RIGHT(elm, field) RB_PTR(RB_RT(elm, field), field)
> #define RB_PARENT(elm, field) (elm)->field.rbe_parent
> -#define RB_COLOR(elm, field) (elm)->field.rbe_color
> -#define RB_ISRED(elm, field) ((elm) != NULL && RB_COLOR(elm, field) ==
> RB_RED)
> #define RB_ROOT(head) (head)->rbh_root
> #define RB_EMPTY(head) (RB_ROOT(head) == NULL)
> +#define RB_BOOL int
> +#define RB_TRUE 1
> +#define RB_FALSE 0
>
> -#define RB_SET(elm, parent, field) do { \
> - RB_PARENT(elm, field) = parent; \
> - RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL; \
> - RB_COLOR(elm, field) = RB_RED; \
> -} while (/*CONSTCOND*/ 0)
> -
> -#define RB_SET_BLACKRED(black, red, field) do { \
> - RB_COLOR(black, field) = RB_BLACK; \
> - RB_COLOR(red, field) = RB_RED; \
> -} while (/*CONSTCOND*/ 0)
> -
> /*
> * Something to be invoked in a loop at the root of every modified
> subtree,
> * from the bottom up to the root, to update augmented node data.
> @@ -344,37 +341,42 @@ struct { \
> #define RB_AUGMENT(x) break
> #endif
>
> +/*
> + * Fix pointers to a parent, and from a parent, as part of rotation.
> + */
> +#define RB_ROTATE_PARENT(head, elm, tmp, field) do { \
> + if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) == NULL) \
> + RB_ROOT(head) = (tmp); \
> + else if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
> + RB_LF(RB_PARENT(elm, field), field) = (tmp); \
> + else \
> + RB_RT(RB_PARENT(elm, field), field) = (tmp); \
> + RB_PARENT(elm, field) = (tmp); \
> +} while (/*CONSTCOND*/ 0)
> +
> +/*
> + * Rotation makes the descending node red, and the ascending
> + * node not-red.
> + */
> #define RB_ROTATE_LEFT(head, elm, tmp, field) do { \
> (tmp) = RB_RIGHT(elm, field); \
> - if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) { \
> + if ((RB_RT(elm, field) = RB_LF(tmp, field)) != NULL) { \
> RB_PARENT(RB_LEFT(tmp, field), field) = (elm); \
> } \
> - if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \
> - if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
> - RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
> - else \
> - RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
> - } else \
> - (head)->rbh_root = (tmp); \
> - RB_LEFT(tmp, field) = (elm); \
> - RB_PARENT(elm, field) = (tmp); \
> + RB_ROTATE_PARENT(head, elm, tmp, field); \
> + RB_LF(tmp, field) = (elm); \
> + RB_FLIP_LF(tmp, field); \
> RB_AUGMENT(elm); \
> } while (/*CONSTCOND*/ 0)
>
> #define RB_ROTATE_RIGHT(head, elm, tmp, field) do { \
> (tmp) = RB_LEFT(elm, field); \
> - if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) { \
> + if ((RB_LF(elm, field) = RB_RT(tmp, field)) != NULL) { \
> RB_PARENT(RB_RIGHT(tmp, field), field) = (elm); \
> } \
> - if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \
> - if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
> - RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
> - else \
> - RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
> - } else \
> - (head)->rbh_root = (tmp); \
> - RB_RIGHT(tmp, field) = (elm); \
> - RB_PARENT(elm, field) = (tmp); \
> + RB_ROTATE_PARENT(head, elm, tmp, field); \
> + RB_RT(tmp, field) = (elm); \
> + RB_FLIP_RT(tmp, field); \
> RB_AUGMENT(elm); \
> } while (/*CONSTCOND*/ 0)
>
> @@ -439,110 +441,105 @@ struct { \
> attr void \
> name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
> { \
> - struct type *parent, *gparent, *tmp; \
> - while (RB_ISRED((parent = RB_PARENT(elm, field)), field)) { \
> - gparent = RB_PARENT(parent, field); \
> - if (parent == RB_LEFT(gparent, field)) { \
> - tmp = RB_RIGHT(gparent, field); \
> - if (RB_ISRED(tmp, field)) { \
> - RB_COLOR(tmp, field) = RB_BLACK; \
> - RB_SET_BLACKRED(parent, gparent, field);\
> - elm = gparent; \
> - continue; \
> - } \
> + struct type *gparent, *parent; \
> + while ((parent = RB_PARENT(elm, field)) != NULL) { \
> + if (RB_LEFT(parent, field) == elm) \
> + RB_FLIP_LF(parent, field); \
> + else \
> + RB_FLIP_RT(parent, field); \
> + if ((gparent = RB_PARENT(parent, field)) == NULL) \
> + break; \
> + if (RB_RED_LF(gparent, field) && \
> + RB_RED_RT(gparent, field)) { \
> + RB_FLIP_LF(gparent, field); \
> + RB_FLIP_RT(gparent, field); \
> + elm = gparent; \
> + continue; \
> + } \
> + if (RB_RED_LF(gparent, field) && \
> + parent == RB_LEFT(gparent, field)) { \
> if (RB_RIGHT(parent, field) == elm) { \
> - RB_ROTATE_LEFT(head, parent, tmp, field);\
> - tmp = parent; \
> + RB_ROTATE_LEFT(head, parent, elm, field);\
> parent = elm; \
> - elm = tmp; \
> } \
> - RB_SET_BLACKRED(parent, gparent, field); \
> - RB_ROTATE_RIGHT(head, gparent, tmp, field); \
> - } else { \
> - tmp = RB_LEFT(gparent, field); \
> - if (RB_ISRED(tmp, field)) { \
> - RB_COLOR(tmp, field) = RB_BLACK; \
> - RB_SET_BLACKRED(parent, gparent, field);\
> - elm = gparent; \
> - continue; \
> - } \
> + RB_ROTATE_RIGHT(head, gparent, parent, field); \
> + } else if (RB_RED_RT(gparent, field) && \
> + parent == RB_RIGHT(gparent, field)) { \
> if (RB_LEFT(parent, field) == elm) { \
> - RB_ROTATE_RIGHT(head, parent, tmp, field);\
> - tmp = parent; \
> + RB_ROTATE_RIGHT(head, parent, elm, field);\
> parent = elm; \
> - elm = tmp; \
> } \
> - RB_SET_BLACKRED(parent, gparent, field); \
> - RB_ROTATE_LEFT(head, gparent, tmp, field); \
> + RB_ROTATE_LEFT(head, gparent, parent, field); \
> } \
> + break; \
> } \
> - RB_COLOR(head->rbh_root, field) = RB_BLACK; \
> }
>
> #define RB_GENERATE_REMOVE_COLOR(name, type, field, attr) \
> attr void \
> -name##_RB_REMOVE_COLOR(struct name *head, struct type *parent) \
> +name##_RB_REMOVE_COLOR(struct name *head, struct type *elm) \
> { \
> - struct type *elm, *tmp; \
> - elm = NULL; \
> + struct type *par, *sib, *tmp; \
> + RB_BOOL go_left, left_child, red_par; \
> + left_child = (RB_LEFT(elm, field) == NULL); \
> do { \
> - if (RB_LEFT(parent, field) == elm) { \
> - tmp = RB_RIGHT(parent, field); \
> - if (RB_COLOR(tmp, field) == RB_RED) { \
> - RB_SET_BLACKRED(tmp, parent, field); \
> - RB_ROTATE_LEFT(head, parent, tmp, field);\
> - tmp = RB_RIGHT(parent, field); \
> + go_left = left_child; \
> + if (go_left ? \
> + !RB_RED_RT(elm, field) : \
> + !RB_RED_LF(elm, field)) { \
> + par = RB_PARENT(elm, field); \
> + left_child = par != NULL && \
> + RB_LEFT(par, field) == elm; \
> + red_par = left_child ? RB_RED_LF(par, field) : \
> + par == NULL ? RB_TRUE : \
> + RB_RED_RT(par, field); \
> + } \
> + if (go_left) { \
> + if (RB_RED_RT(elm, field)) { \
> + red_par = RB_TRUE; \
> + RB_ROTATE_LEFT(head, elm, par, field); \
> } \
> - if (RB_ISRED(RB_LEFT(tmp, field), field)) { \
> - struct type *oleft; \
> - oleft = RB_LEFT(tmp, field); \
> - RB_COLOR(oleft, field) = RB_BLACK; \
> - RB_COLOR(tmp, field) = RB_RED; \
> - RB_ROTATE_RIGHT(head, tmp, oleft, field); \
> - tmp = RB_RIGHT(parent, field); \
> - } else if (!RB_ISRED(RB_RIGHT(tmp, field), field)) { \
> - RB_COLOR(tmp, field) = RB_RED; \
> - elm = parent; \
> - parent = RB_PARENT(elm, field); \
> + sib = RB_RIGHT(elm, field); \
> + if (RB_RED_LF(sib, field)) { \
> + RB_ROTATE_RIGHT(head, sib, tmp, field); \
> + sib = tmp; \
> + } else if (!RB_RED_RT(sib, field)) { \
> + RB_FLIP_RT(elm, field); \
> + elm = par; \
> continue; \
> } \
> - if (RB_ISRED(RB_RIGHT(tmp, field), field)) \
> - RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK; \
> - RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
> - RB_COLOR(parent, field) = RB_BLACK; \
> - RB_ROTATE_LEFT(head, parent, tmp, field); \
> - elm = RB_ROOT(head); \
> + if (RB_RED_RT(sib, field)) \
> + RB_FLIP_RT(sib, field); \
> + RB_ROTATE_LEFT(head, elm, sib, field); \
> + RB_FLIP_LF(sib, field); \
> break; \
> } else { \
> - tmp = RB_LEFT(parent, field); \
> - if (RB_COLOR(tmp, field) == RB_RED) { \
> - RB_SET_BLACKRED(tmp, parent, field); \
> - RB_ROTATE_RIGHT(head, parent, tmp, field);\
> - tmp = RB_LEFT(parent, field); \
> + if (RB_RED_LF(elm, field)) { \
> + red_par = RB_TRUE; \
> + RB_ROTATE_RIGHT(head, elm, par, field); \
> } \
> - if (RB_ISRED(RB_RIGHT(tmp, field), field)) { \
> - struct type *oright; \
> - oright = RB_RIGHT(tmp, field); \
> - RB_COLOR(oright, field) = RB_BLACK; \
> - RB_COLOR(tmp, field) = RB_RED; \
> - RB_ROTATE_LEFT(head, tmp, oright, field); \
> - tmp = RB_LEFT(parent, field); \
> - } else if (!RB_ISRED(RB_LEFT(tmp, field), field)) { \
> - RB_COLOR(tmp, field) = RB_RED; \
> - elm = parent; \
> - parent = RB_PARENT(elm, field); \
> + sib = RB_LEFT(elm, field); \
> + if (RB_RED_RT(sib, field)) { \
> + RB_ROTATE_LEFT(head, sib, tmp, field); \
> + sib = tmp; \
> + } else if (!RB_RED_LF(sib, field)) { \
> + RB_FLIP_LF(elm, field); \
> + elm = par; \
> continue; \
> } \
> - if (RB_ISRED(RB_LEFT(tmp, field), field)) \
> - RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK; \
> - RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
> - RB_COLOR(parent, field) = RB_BLACK; \
> - RB_ROTATE_RIGHT(head, parent, tmp, field); \
> - elm = RB_ROOT(head); \
> + if (RB_RED_LF(sib, field)) \
> + RB_FLIP_LF(sib, field); \
> + RB_ROTATE_RIGHT(head, elm, sib, field); \
> + RB_FLIP_RT(sib, field); \
> break; \
> } \
> - } while (!RB_ISRED(elm, field) && parent != NULL); \
> - RB_COLOR(elm, field) = RB_BLACK; \
> + } while (!red_par); \
> + if (par != NULL && red_par) { \
> + if (left_child) \
> + RB_FLIP_LF(par, field); \
> + else \
> + RB_FLIP_RT(par, field); \
> + } \
> }
>
> #define RB_GENERATE_REMOVE(name, type, field, attr) \
> @@ -550,12 +547,11 @@ attr struct type * \
> name##_RB_REMOVE(struct name *head, struct type *elm) \
> { \
> struct type *child, *old, *parent, *parent_old, *right; \
> - int color; \
> + RB_BOOL old_red, red; \
> \
> old = elm; \
> parent_old = parent = RB_PARENT(elm, field); \
> right = RB_RIGHT(elm, field); \
> - color = RB_COLOR(elm, field); \
> if (RB_LEFT(elm, field) == NULL) \
> elm = child = right; \
> else if (right == NULL) \
> @@ -563,7 +559,8 @@ name##_RB_REMOVE(struct name *head, struct type *elm)
> else { \
> if ((child = RB_LEFT(right, field)) == NULL) { \
> child = RB_RIGHT(right, field); \
> - RB_RIGHT(old, field) = child; \
> + red = RB_RED_RT(old, field); \
> + RB_RT(old, field) = child; \
> parent = elm = right; \
> } else { \
> do \
> @@ -571,23 +568,31 @@ name##_RB_REMOVE(struct name *head, struct type
> *elm)
> while ((child = RB_LEFT(elm, field)) != NULL); \
> child = RB_RIGHT(elm, field); \
> parent = RB_PARENT(elm, field); \
> - RB_LEFT(parent, field) = child; \
> + red = RB_RED_LF(parent, field); \
> + RB_LF(parent, field) = child; \
> RB_PARENT(RB_RIGHT(old, field), field) = elm; \
> } \
> RB_PARENT(RB_LEFT(old, field), field) = elm; \
> - color = RB_COLOR(elm, field); \
> elm->field = old->field; \
> } \
> - if (parent_old == NULL) \
> + if (parent_old == NULL) { \
> RB_ROOT(head) = elm; \
> - else if (RB_LEFT(parent_old, field) == old) \
> - RB_LEFT(parent_old, field) = elm; \
> - else \
> - RB_RIGHT(parent_old, field) = elm; \
> - if (child != NULL) { \
> + old_red = RB_FALSE; \
> + } else if (RB_LEFT(parent_old, field) == old) { \
> + old_red = RB_RED_LF(parent_old, field); \
> + RB_LF(parent_old, field) = elm; \
> + if (old_red && parent != parent_old) \
> + RB_FLIP_LF(parent_old, field); \
> + } else { \
> + old_red = RB_RED_RT(parent_old, field); \
> + RB_RT(parent_old, field) = elm; \
> + if (old_red && parent != parent_old) \
> + RB_FLIP_RT(parent_old, field); \
> + } \
> + if (child != NULL) \
> RB_PARENT(child, field) = parent; \
> - RB_COLOR(child, field) = RB_BLACK; \
> - } else if (color != RB_RED && parent != NULL) \
> + else if (parent != NULL && \
> + (parent != parent_old ? !red : !old_red)) \
> name##_RB_REMOVE_COLOR(head, parent); \
> while (parent != NULL) { \
> RB_AUGMENT(parent); \
> @@ -615,14 +620,14 @@ name##_RB_INSERT(struct name *head, struct type
> *elm)
> else \
> return (tmp); \
> } \
> - RB_SET(elm, parent, field); \
> - if (parent != NULL) { \
> - if (comp < 0) \
> - RB_LEFT(parent, field) = elm; \
> - else \
> - RB_RIGHT(parent, field) = elm; \
> - } else \
> + RB_PARENT(elm, field) = parent; \
> + RB_LF(elm, field) = RB_RT(elm, field) = NULL; \
> + if (parent == NULL) \
> RB_ROOT(head) = elm; \
> + else if (comp < 0) \
> + RB_LF(parent, field) = elm; \
> + else \
> + RB_RT(parent, field) = elm; \
> name##_RB_INSERT_COLOR(head, elm); \
> while (elm != NULL) { \
> RB_AUGMENT(elm); \
>
--
Mateusz Guzik <mjguzik gmail.com>
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