linux-stable.git/include/linux/netdevice.h, branch v6.14.3

Revert "net: skb: introduce and use a single page frag cache"

2025-02-20T09:53:25+00:00

After the previous commit is finally safe to revert commit dbae2b062824
("net: skb: introduce and use a single page frag cache"): do it here.

The intended goal of such change was to counter a performance regression
introduced by commit 3226b158e67c ("net: avoid 32 x truesize
under-estimation for tiny skbs").

Unfortunately, the blamed commit introduces another regression for the
virtio_net driver. Such a driver calls napi_alloc_skb() with a tiny
size, so that the whole head frag could fit a 512-byte block.

The single page frag cache uses a 1K fragment for such allocation, and
the additional overhead, under small UDP packets flood, makes the page
allocator a bottleneck.

Thanks to commit bf9f1baa279f ("net: add dedicated kmem_cache for
typical/small skb->head"), this revert does not re-introduce the
original regression. Actually, in the relevant test on top of this
revert, I measure a small but noticeable positive delta, just above
noise level.

The revert itself required some additional mangling due to recent updates
in the affected code.

Suggested-by: Eric Dumazet 
Fixes: dbae2b062824 ("net: skb: introduce and use a single page frag cache")
Reviewed-by: Eric Dumazet 
Signed-off-by: Paolo Abeni

net: Add non-RCU dev_getbyhwaddr() helper

2025-02-20T02:59:29+00:00

Add dedicated helper for finding devices by hardware address when
holding rtnl_lock, similar to existing dev_getbyhwaddr_rcu(). This prevents
PROVE_LOCKING warnings when rtnl_lock is held but RCU read lock is not.

Extract common address comparison logic into dev_addr_cmp().

The context about this change could be found in the following
discussion:

Link: https://lore.kernel.org/all/20250206-scarlet-ermine-of-improvement-1fcac5@leitao/

Cc: kuniyu@amazon.com
Cc: ushankar@purestorage.com
Suggested-by: Eric Dumazet 
Signed-off-by: Breno Leitao 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-1-d3d6892db9e1@debian.org
Signed-off-by: Jakub Kicinski

Reapply "net: skb: introduce and use a single page frag cache"

2025-02-13T16:49:44+00:00

This reverts commit 011b0335903832facca86cd8ed05d7d8d94c9c76.

Sabrina reports that the revert may trigger warnings due to intervening
changes, especially the ability to rise MAX_SKB_FRAGS. Let's drop it
and revisit once that part is also ironed out.

Fixes: 011b03359038 ("Revert "net: skb: introduce and use a single page frag cache"")
Reported-by: Sabrina Dubroca 
Link: https://lore.kernel.org/6bf54579233038bc0e76056c5ea459872ce362ab.1739375933.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski

Revert "net: skb: introduce and use a single page frag cache"

2025-02-08T01:20:22+00:00

This reverts commit dbae2b062824 ("net: skb: introduce and use a single
page frag cache"). The intended goal of such change was to counter a
performance regression introduced by commit 3226b158e67c ("net: avoid
32 x truesize under-estimation for tiny skbs").

Unfortunately, the blamed commit introduces another regression for the
virtio_net driver. Such a driver calls napi_alloc_skb() with a tiny
size, so that the whole head frag could fit a 512-byte block.

The single page frag cache uses a 1K fragment for such allocation, and
the additional overhead, under small UDP packets flood, makes the page
allocator a bottleneck.

Thanks to commit bf9f1baa279f ("net: add dedicated kmem_cache for
typical/small skb->head"), this revert does not re-introduce the
original regression. Actually, in the relevant test on top of this
revert, I measure a small but noticeable positive delta, just above
noise level.

The revert itself required some additional mangling due to the
introduction of the SKB_HEAD_ALIGN() helper and local lock infra in the
affected code.

Suggested-by: Eric Dumazet 
Fixes: dbae2b062824 ("net: skb: introduce and use a single page frag cache")
Signed-off-by: Paolo Abeni 
Link: https://patch.msgid.link/e649212fde9f0fdee23909ca0d14158d32bb7425.1738877290.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski

net: add dev_net_rcu() helper

2025-02-07T00:14:14+00:00

dev->nd_net can change, readers should either
use rcu_read_lock() or RTNL.

We currently use a generic helper, dev_net() with
no debugging support. We probably have many hidden bugs.

Add dev_net_rcu() helper for callers using rcu_read_lock()
protection.

Signed-off-by: Eric Dumazet 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: harmonize tstats and dstats

2025-02-04T02:39:59+00:00

After the blamed commits below, some UDP tunnel use dstats for
accounting. On the xmit path, all the UDP-base tunnels ends up
using iptunnel_xmit_stats() for stats accounting, and the latter
assumes the relevant (tunnel) network device uses tstats.

The end result is some 'funny' stat report for the mentioned UDP
tunnel, e.g. when no packet is actually dropped and a bunch of
packets are transmitted:

gnv2:  mtu 1450 qdisc noqueue \
		state UNKNOWN mode DEFAULT group default qlen 1000
    link/ether ee:7d:09:87:90:ea brd ff:ff:ff:ff:ff:ff
    RX:  bytes packets errors dropped  missed   mcast
         14916      23      0      15       0       0
    TX:  bytes packets errors dropped carrier collsns
             0    1566      0       0       0       0

Address the issue ensuring the same binary layout for the overlapping
fields of dstats and tstats. While this solution is a bit hackish, is
smaller and with no performance pitfall compared to other alternatives
i.e. supporting both dstat and tstat in iptunnel_xmit_stats() or
reverting the blamed commit.

With time we should possibly move all the IP-based tunnel (and virtual
devices) to dstats.

Fixes: c77200c07491 ("bareudp: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: 6fa6de302246 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: be226352e8dc ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Signed-off-by: Paolo Abeni 
Reviewed-by: Guillaume Nault 
Link: https://patch.msgid.link/2e1c444cf0f63ae472baff29862c4c869be17031.1738432804.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski

net: the appletalk subsystem no longer uses ndo_do_ioctl

2025-01-27T22:07:19+00:00

ndo_do_ioctl is no longer used by the appletalk subsystem after commit
45bd1c5ba758 ("net: appletalk: Drop aarp_send_probe_phase1()").

Signed-off-by: 谢致邦 (XIE Zhibang) 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/tencent_4AC6ED413FEA8116B4253D3ED6947FDBCF08@qq.com
Signed-off-by: Jakub Kicinski

net: provide pending ring configuration in net_device

2025-01-20T19:44:57+00:00

Record the pending configuration in net_device struct.
ethtool core duplicates the current config and the specific
handlers (for now just ringparam) can modify it.

Reviewed-by: Michael Chan 
Link: https://patch.msgid.link/20250119020518.1962249-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: move HDS config from ethtool state

2025-01-20T19:44:57+00:00

Separate the HDS config from the ethtool state struct.
The HDS config contains just simple parameters, not state.
Having it as a separate struct will make it easier to clone / copy
and also long term potentially make it per-queue.

Reviewed-by: Michael Chan 
Link: https://patch.msgid.link/20250119020518.1962249-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: protect NAPI config fields with netdev_lock()

2025-01-16T03:13:34+00:00

Protect the following members of netdev and napi by netdev_lock:
 - defer_hard_irqs,
 - gro_flush_timeout,
 - irq_suspend_timeout.

The first two are written via sysfs (which this patch switches
to new lock), and netdev genl which holds both netdev and rtnl locks.

irq_suspend_timeout is only written by netdev genl.

Reviewed-by: Joe Damato 
Reviewed-by: Eric Dumazet 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250115035319.559603-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski