[PATCH v2 net-next 0/4] net: core: use a dedicated kmem_cache for skb head allocs

From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com,
	Soheil Hassas Yeganeh <soheil@google.com>,
	Eric Dumazet <edumazet@google.com>
Subject: [PATCH v2 net-next 0/4] net: core: use a dedicated kmem_cache for skb head allocs
Date: Mon,  6 Feb 2023 17:30:59 +0000	[thread overview]
Message-ID: <20230206173103.2617121-1-edumazet@google.com> (raw)

Our profile data show that using kmalloc(non_const_size)/kfree(ptr)
has a certain cost, because kfree(ptr) has to pull a 'struct page'
in cpu caches.

Using a dedicated kmem_cache for TCP skb->head allocations makes
a difference, both in cpu cycles and memory savings.

This kmem_cache could also be used for GRO skb allocations,
this is left as a future exercise.

v2: addressed compile error with CONFIG_SLOB=y (kernel bots)
    Changed comment (Jakub)

Eric Dumazet (4):
  net: add SKB_HEAD_ALIGN() helper
  net: remove osize variable in __alloc_skb()
  net: factorize code in kmalloc_reserve()
  net: add dedicated kmem_cache for typical/small skb->head

 include/linux/skbuff.h |   8 +++
 net/core/skbuff.c      | 115 +++++++++++++++++++++++++++++------------
 2 files changed, 90 insertions(+), 33 deletions(-)

-- 
2.39.1.519.gcb327c4b5f-goog