[PATCH net-next 1/4] net: always inline skb_frag_unref() and __skb_frag_unref()

[Eric Dumazet <edumazet@google.com>]

clang is not inlining skb_frag_unref() and __skb_frag_unref()
in gro fast path.

It also does not inline gro_try_pull_from_frag0().

Using __always_inline fixes this issue, makes the
kernel faster _and_ smaller.

Also change __skb_frag_ref(), skb_frag_ref() and skb_page_unref()
to let them inlined for the last patch in this series.

$ scripts/bloat-o-meter -t vmlinux.0 vmlinux.1
add/remove: 2/6 grow/shrink: 1/2 up/down: 218/-511 (-293)
Function                                     old     new   delta
gro_pull_from_frag0                            -     188    +188
__pfx_gro_pull_from_frag0                      -      16     +16
skb_shift                                   1125    1139     +14
__pfx_skb_frag_unref                          16       -     -16
__pfx_gro_try_pull_from_frag0                 16       -     -16
__pfx___skb_frag_unref                        16       -     -16
__skb_frag_unref                              36       -     -36
skb_frag_unref                                59       -     -59
dev_gro_receive                             1608    1514     -94
napi_gro_frags                               892     771    -121
gro_try_pull_from_frag0                      153       -    -153
Total: Before=22566192, After=22565899, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/skbuff_ref.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/skbuff_ref.h b/include/linux/skbuff_ref.h
index 9e49372ef1a05efdfd4cb42973fbce109332d5bf..05c8486bafac83dba4e52ffee23d8a19c92b8f27 100644
--- a/include/linux/skbuff_ref.h
+++ b/include/linux/skbuff_ref.h
@@ -15,7 +15,7 @@
  *
  * Takes an additional reference on the paged fragment @frag.
  */
-static inline void __skb_frag_ref(skb_frag_t *frag)
+static __always_inline void __skb_frag_ref(skb_frag_t *frag)
 {
 	get_netmem(skb_frag_netmem(frag));
 }
@@ -27,14 +27,14 @@ static inline void __skb_frag_ref(skb_frag_t *frag)
  *
  * Takes an additional reference on the @f'th paged fragment of @skb.
  */
-static inline void skb_frag_ref(struct sk_buff *skb, int f)
+static __always_inline void skb_frag_ref(struct sk_buff *skb, int f)
 {
 	__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
 }
 
 bool napi_pp_put_page(netmem_ref netmem);
 
-static inline void skb_page_unref(netmem_ref netmem, bool recycle)
+static __always_inline void skb_page_unref(netmem_ref netmem, bool recycle)
 {
 #ifdef CONFIG_PAGE_POOL
 	if (recycle && napi_pp_put_page(netmem))
@@ -51,7 +51,7 @@ static inline void skb_page_unref(netmem_ref netmem, bool recycle)
  * Releases a reference on the paged fragment @frag
  * or recycles the page via the page_pool API.
  */
-static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
+static __always_inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
 {
 	skb_page_unref(skb_frag_netmem(frag), recycle);
 }
@@ -63,7 +63,7 @@ static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
  *
  * Releases a reference on the @f'th paged fragment of @skb.
  */
-static inline void skb_frag_unref(struct sk_buff *skb, int f)
+static __always_inline void skb_frag_unref(struct sk_buff *skb, int f)
 {
 	struct skb_shared_info *shinfo = skb_shinfo(skb);
 
-- 
2.52.0.457.g6b5491de43-goog