From c2d2dad24503d7e2eb7cba354fcc73f95fa78d7a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 14 Nov 2025 14:06:45 +0000 Subject: 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 Signed-off-by: Miguel Ojeda Reviewed-by: Kuan-Wei Chiu Cc: Jakub Kacinski Cc: Neal Cardwell Cc: Paolo Abeni Cc: Alice Ryhl Cc: Stehen Rothwell Signed-off-by: Andrew Morton --- lib/rbtree.c | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'lib/rbtree.c') diff --git a/lib/rbtree.c b/lib/rbtree.c index 5114eda6309c..b946eb4b759d 100644 --- a/lib/rbtree.c +++ b/lib/rbtree.c @@ -460,22 +460,6 @@ void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, } EXPORT_SYMBOL(__rb_insert_augmented); -/* - * This function returns the first node (in sort order) of the tree. - */ -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; -} -EXPORT_SYMBOL(rb_first); - struct rb_node *rb_last(const struct rb_root *root) { struct rb_node *n; -- cgit From 94984bfed58ca129f7e259ce09973ed0b3f540a8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 14 Nov 2025 14:06:46 +0000 Subject: rbtree: inline rb_last() This is a very small function, inlining it saves cpu cycles in TCP by reducing register pressure and removing call/ret overhead. It also reduces vmlinux text size by 122 bytes on a typical x86_64 build. Before: size vmlinux text data bss dec hex filename 34811781 22177365 5685248 62674394 3bc55da vmlinux After: size vmlinux text data bss dec hex filename 34811659 22177365 5685248 62674272 3bc5560 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/20251114140646.3817319-3-edumazet@google.com Signed-off-by: Eric Dumazet Signed-off-by: Miguel Ojeda Reviewed-by: Kuan-Wei Chiu Cc: Jakub Kacinski Cc: Neal Cardwell Cc: Paolo Abeni Cc: Alice Ryhl Cc: Stehen Rothwell Signed-off-by: Andrew Morton --- lib/rbtree.c | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'lib/rbtree.c') diff --git a/lib/rbtree.c b/lib/rbtree.c index b946eb4b759d..18d42bcf4ec9 100644 --- a/lib/rbtree.c +++ b/lib/rbtree.c @@ -460,19 +460,6 @@ void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, } EXPORT_SYMBOL(__rb_insert_augmented); -struct rb_node *rb_last(const struct rb_root *root) -{ - struct rb_node *n; - - n = root->rb_node; - if (!n) - return NULL; - while (n->rb_right) - n = n->rb_right; - return n; -} -EXPORT_SYMBOL(rb_last); - struct rb_node *rb_next(const struct rb_node *node) { struct rb_node *parent; -- cgit