2023-05-09 07:31:44

by Lukas Bulwahn

[permalink] [raw]
Subject: [PATCH] net: skbuff: remove special handling for SLOB

Commit c9929f0e344a ("mm/slob: remove CONFIG_SLOB") removes CONFIG_SLOB.
Now, we can also remove special handling for socket buffers with the SLOB
allocator. The code with HAVE_SKB_SMALL_HEAD_CACHE=1 is now the default
behavior for all allocators.

Remove an unnecessary distinction between SLOB and SLAB/SLUB allocator
after the SLOB allocator is gone.

Signed-off-by: Lukas Bulwahn <[email protected]>
---
net/core/skbuff.c | 17 -----------------
1 file changed, 17 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 515ec5cdc79c..01b48e68aca0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -92,15 +92,7 @@ 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)
@@ -117,7 +109,6 @@ 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);
@@ -562,7 +553,6 @@ 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)) {
obj = kmem_cache_alloc_node(skb_small_head_cache,
@@ -576,7 +566,6 @@ static void *kmalloc_reserve(unsigned int *size, gfp_t flags, int node,
obj = kmem_cache_alloc_node(skb_small_head_cache, flags, node);
goto out;
}
-#endif
*size = obj_size = kmalloc_size_roundup(obj_size);
/*
* Try a regular allocation, when that fails and we're not entitled
@@ -898,11 +887,9 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data, bool napi_safe)

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);
}

@@ -2160,7 +2147,6 @@ int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
if (likely(skb_end_offset(skb) == saved_end_offset))
return 0;

-#ifdef HAVE_SKB_SMALL_HEAD_CACHE
/* We can not change skb->end if the original or new value
* is SKB_SMALL_HEAD_HEADROOM, as it might break skb_kfree_head().
*/
@@ -2174,7 +2160,6 @@ int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
WARN_ON_ONCE(1);
return 0;
}
-#endif

shinfo = skb_shinfo(skb);

@@ -4768,7 +4753,6 @@ 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.
@@ -4780,7 +4764,6 @@ void __init skb_init(void)
0,
SKB_SMALL_HEAD_HEADROOM,
NULL);
-#endif
skb_extensions_init();
}

--
2.17.1


2023-05-09 08:22:52

by Leon Romanovsky

[permalink] [raw]
Subject: Re: [PATCH] net: skbuff: remove special handling for SLOB

On Tue, May 09, 2023 at 09:12:07AM +0200, Lukas Bulwahn wrote:
> Commit c9929f0e344a ("mm/slob: remove CONFIG_SLOB") removes CONFIG_SLOB.
> Now, we can also remove special handling for socket buffers with the SLOB
> allocator. The code with HAVE_SKB_SMALL_HEAD_CACHE=1 is now the default
> behavior for all allocators.
>
> Remove an unnecessary distinction between SLOB and SLAB/SLUB allocator
> after the SLOB allocator is gone.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>
> ---
> net/core/skbuff.c | 17 -----------------
> 1 file changed, 17 deletions(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <[email protected]>

2023-05-09 09:26:31

by Eric Dumazet

[permalink] [raw]
Subject: Re: [PATCH] net: skbuff: remove special handling for SLOB

On Tue, May 9, 2023 at 9:12 AM Lukas Bulwahn <[email protected]> wrote:
>
> Commit c9929f0e344a ("mm/slob: remove CONFIG_SLOB") removes CONFIG_SLOB.
> Now, we can also remove special handling for socket buffers with the SLOB
> allocator. The code with HAVE_SKB_SMALL_HEAD_CACHE=1 is now the default
> behavior for all allocators.
>
> Remove an unnecessary distinction between SLOB and SLAB/SLUB allocator
> after the SLOB allocator is gone.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>

Reviewed-by: Eric Dumazet <[email protected]>

2023-05-10 03:18:18

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH] net: skbuff: remove special handling for SLOB

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:

On Tue, 9 May 2023 09:12:07 +0200 you wrote:
> Commit c9929f0e344a ("mm/slob: remove CONFIG_SLOB") removes CONFIG_SLOB.
> Now, we can also remove special handling for socket buffers with the SLOB
> allocator. The code with HAVE_SKB_SMALL_HEAD_CACHE=1 is now the default
> behavior for all allocators.
>
> Remove an unnecessary distinction between SLOB and SLAB/SLUB allocator
> after the SLOB allocator is gone.
>
> [...]

Here is the summary with links:
- net: skbuff: remove special handling for SLOB
https://git.kernel.org/netdev/net-next/c/559ae55cfc33

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


2023-05-15 08:53:33

by Vlastimil Babka

[permalink] [raw]
Subject: Re: [PATCH] net: skbuff: remove special handling for SLOB

On 5/9/23 09:12, Lukas Bulwahn wrote:
> Commit c9929f0e344a ("mm/slob: remove CONFIG_SLOB") removes CONFIG_SLOB.
> Now, we can also remove special handling for socket buffers with the SLOB
> allocator. The code with HAVE_SKB_SMALL_HEAD_CACHE=1 is now the default
> behavior for all allocators.
>
> Remove an unnecessary distinction between SLOB and SLAB/SLUB allocator
> after the SLOB allocator is gone.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>

Acked-by: Vlastimil Babka <[email protected]>