[PATCH 2/7] net: skbuff: remove SLOB-specific ifdefs

From: Vlastimil Babka
Date: Fri Mar 10 2023 - 05:32:31 EST


As the comment for HAVE_SKB_SMALL_HEAD_CACHE says:

> skb_small_head_cache and related code is only supported
> for CONFIG_SLAB and CONFIG_SLUB.
> As soon as SLOB is removed from the kernel, we can clean up this.

With CONFIG_SLOB removed, remove HAVE_SKB_SMALL_HEAD_CACHE and make all
code that it guards unconditional.

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
---
net/core/skbuff.c | 16 ----------------
1 file changed, 16 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index eb7d33b41e71..8bba4e91d0d5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -90,15 +90,6 @@ static struct kmem_cache *skbuff_fclone_cache __ro_after_init;
static struct kmem_cache *skbuff_ext_cache __ro_after_init;
#endif

-/* skb_small_head_cache and related code is only supported
- * for CONFIG_SLAB and CONFIG_SLUB.
- * As soon as SLOB is removed from the kernel, we can clean up this.
- */
-#if !defined(CONFIG_SLOB)
-# define HAVE_SKB_SMALL_HEAD_CACHE 1
-#endif
-
-#ifdef HAVE_SKB_SMALL_HEAD_CACHE
static struct kmem_cache *skb_small_head_cache __ro_after_init;

#define SKB_SMALL_HEAD_SIZE SKB_HEAD_ALIGN(MAX_TCP_HEADER)
@@ -115,7 +106,6 @@ static struct kmem_cache *skb_small_head_cache __ro_after_init;

#define SKB_SMALL_HEAD_HEADROOM \
SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE)
-#endif /* HAVE_SKB_SMALL_HEAD_CACHE */

int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS;
EXPORT_SYMBOL(sysctl_max_skb_frags);
@@ -514,7 +504,6 @@ static void *kmalloc_reserve(unsigned int *size, gfp_t flags, int node,
void *obj;

obj_size = SKB_HEAD_ALIGN(*size);
-#ifdef HAVE_SKB_SMALL_HEAD_CACHE
if (obj_size <= SKB_SMALL_HEAD_CACHE_SIZE &&
!(flags & KMALLOC_NOT_NORMAL_BITS)) {

@@ -530,7 +519,6 @@ static void *kmalloc_reserve(unsigned int *size, gfp_t flags, int node,
goto out;
}
}
-#endif
*size = obj_size = kmalloc_size_roundup(obj_size);
/*
* Try a regular allocation, when that fails and we're not entitled
@@ -852,11 +840,9 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data)

static void skb_kfree_head(void *head, unsigned int end_offset)
{
-#ifdef HAVE_SKB_SMALL_HEAD_CACHE
if (end_offset == SKB_SMALL_HEAD_HEADROOM)
kmem_cache_free(skb_small_head_cache, head);
else
-#endif
kfree(head);
}

@@ -4692,7 +4678,6 @@ void __init skb_init(void)
0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
NULL);
-#ifdef HAVE_SKB_SMALL_HEAD_CACHE
/* usercopy should only access first SKB_SMALL_HEAD_HEADROOM bytes.
* struct skb_shared_info is located at the end of skb->head,
* and should not be copied to/from user.
@@ -4704,7 +4689,6 @@ void __init skb_init(void)
0,
SKB_SMALL_HEAD_HEADROOM,
NULL);
-#endif
skb_extensions_init();
}

--
2.39.2