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authorZeng Chi <zengchi@kylinos.cn>2026-09-21 18:24:42 +0800
committerSean Christopherson <seanjc@google.com>2026-09-22 08:36:16 -0700
commit119e9db233ad0f4cbd4cfb9f9385a7bca378b37d (patch)
tree660d50d4139cb750fbde1ae3432452c20726c99d /Documentation/networking/skbuff.rst
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KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted
Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson <seanjc@google.com> Cc: David Ballesteros <davimaba.v@proton.me> Signed-off-by: Zeng Chi <zengchi@kylinos.cn> Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson <seanjc@google.com>
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+.. SPDX-License-Identifier: GPL-2.0
+
+struct sk_buff
+==============
+
+:c:type:`sk_buff` is the main networking structure representing
+a packet.
+
+Basic sk_buff geometry
+----------------------
+
+.. kernel-doc:: include/linux/skbuff.h
+ :doc: Basic sk_buff geometry
+
+Shared skbs and skb clones
+--------------------------
+
+:c:member:`sk_buff.users` is a simple refcount allowing multiple entities
+to keep a struct sk_buff alive. skbs with a ``sk_buff.users != 1`` are referred
+to as shared skbs (see skb_shared()).
+
+skb_clone() allows for fast duplication of skbs. None of the data buffers
+get copied, but caller gets a new metadata struct (struct sk_buff).
+&skb_shared_info.refcount indicates the number of skbs pointing at the same
+packet data (i.e. clones).
+
+dataref and headerless skbs
+---------------------------
+
+.. kernel-doc:: include/linux/skbuff.h
+ :doc: dataref and headerless skbs