diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-11-14 14:06:45 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-27 14:24:30 -0800 |
| commit | c2d2dad24503d7e2eb7cba354fcc73f95fa78d7a (patch) | |
| tree | f1e3027426836dd1627cdf01f8320db8db69e24d /include/linux | |
| parent | bc947af67759c2d229e31af9bf232f9ade6145d8 (diff) | |
rbtree: inline rb_first()
Patch series "rbree: inline rb_first() and rb_last()".
Inline these two small helpers, heavily used in TCP and FQ packet scheduler,
and in many other places.
This reduces kernel text size, and brings an 1.5 % improvement on network
TCP stress test.
This patch (of 2):
This is a very small function, inlining it saves cpu cycles by reducing
register pressure and removing call/ret overhead.
It also reduces vmlinux text size by 744 bytes on a typical x86_64 build.
Before:
size vmlinux
text data bss dec hex filename
34812525 22177365 5685248 62675138 3bc58c2 vmlinux
After:
size vmlinux
text data bss dec hex filename
34811781 22177365 5685248 62674394 3bc55da vmlinux
[ojeda@kernel.org: fix rust build]
Link: https://lkml.kernel.org/r/20251120085518.1463498-1-ojeda@kernel.org
Link: https://lkml.kernel.org/r/20251114140646.3817319-1-edumazet@google.com
Link: https://lkml.kernel.org/r/20251114140646.3817319-2-edumazet@google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rbtree.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index 8d2ba3749866..484554900f7d 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -43,7 +43,21 @@ extern void rb_erase(struct rb_node *, struct rb_root *); /* Find logical next and previous nodes in a tree */ extern struct rb_node *rb_next(const struct rb_node *); extern struct rb_node *rb_prev(const struct rb_node *); -extern struct rb_node *rb_first(const struct rb_root *); + +/* + * This function returns the first node (in sort order) of the tree. + */ +static inline struct rb_node *rb_first(const struct rb_root *root) +{ + struct rb_node *n; + + n = root->rb_node; + if (!n) + return NULL; + while (n->rb_left) + n = n->rb_left; + return n; +} extern struct rb_node *rb_last(const struct rb_root *); /* Postorder iteration - always visit the parent after its children */ |