This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Although unlikely, recent support for IPIP tunnels increases chances of
reaching this WARN_ON_ONCE if userspace manages to build a sufficiently
long forward path.
Remove it.
Fixes: ddb94eafab ("net: resolve forwarding path from virtual netdevice and HW destination address")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the GSO TX path, that used to check and remove
HBH.
Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260205133925.526371-5-alice.kernel@fastmail.im
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We should follow the prepare/commit approach for queue configuration.
The qcfg struct should be added to dev->cfg rather than directly to
queue objects so that we can clone and discard the pending config
easily.
Remove the qcfg in struct netdev_rx_queue, and switch remaining callers
to netdev_queue_config(). netdev_queue_config() will construct the qcfg
on the fly based on device defaults and state of the queue.
ndo_default_qcfg becomes optional because having the callback itself
does not have any meaningful semantics to us.
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://patch.msgid.link/20260122005113.2476634-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some/most devices implementing gso_partial need to disable the GSO partial
features when the IP ID can't be mangled; to that extend each of them
implements something alike the following[1]:
if (skb->encapsulation && !(features & NETIF_F_TSO_MANGLEID))
features &= ~NETIF_F_TSO;
in the ndo_features_check() op, which leads to a bit of duplicate code.
Later patch in the series will implement GSO partial support for virtual
devices, and the current status quo will require more duplicate code and
a new indirect call in the TX path for them.
Introduce the mangleid_features mask, allowing the core to disable NIC
features based on/requiring MANGLEID, without any further intervention
from the driver.
The same functionality could be alternatively implemented adding a single
boolean flag to the struct net_device, but would require an additional
checks in ndo_features_check().
Also note that [1] is incorrect if the NIC additionally implements
NETIF_F_GSO_UDP_L4, mangleid_features transparently handle even such a
case.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/5a7cdaeea40b0a29b88e525b6c942d73ed3b8ce7.1769011015.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pavel Begunkov says:
====================
Add support for providers with large rx buffer
Many modern NICs support configurable receive buffer lengths, and zcrx and
memory providers can use buffers larger than 4K to improve performance.
When paired with hw-gro larger rx buffer sizes can drastically reduce
the number of buffers traversing the stack and save a lot of processing
time. It also allows to give to users larger contiguous chunks of data.
Single stream benchmarks showed up to ~30% CPU util improvement.
E.g. comparison for 4K vs 32K buffers using a 200Gbit NIC:
packets=23987040 (MB=2745098), rps=199559 (MB/s=22837)
CPU %usr %nice %sys %iowait %irq %soft %idle
0 1.53 0.00 27.78 2.72 1.31 66.45 0.22
packets=24078368 (MB=2755550), rps=200319 (MB/s=22924)
CPU %usr %nice %sys %iowait %irq %soft %idle
0 0.69 0.00 8.26 31.65 1.83 57.00 0.57
This series adds net infrastructure for memory providers configuring
the size and implements it for bnxt. It's an opt-in feature for drivers,
they should advertise support for the parameter in the qops and must check
if the hardware supports the given size. It's limited to memory providers
as it drastically simplifies implementation. It doesn't affect the fast
path zcrx uAPI, and the user exposed parameter is defined in zcrx terms,
which allows it to be flexible and adjusted in the future.
A liburing example can be found at [2]
full branch:
[1] https://github.com/isilence/linux.git zcrx/large-buffers-v8
Liburing example:
[2] https://github.com/isilence/liburing.git zcrx/rx-buf-len
* tag 'net-queue-rx-buf-len-v9' of https://github.com/isilence/linux:
io_uring/zcrx: document area chunking parameter
selftests: iou-zcrx: test large chunk sizes
eth: bnxt: support qcfg provided rx page size
eth: bnxt: adjust the fill level of agg queues with larger buffers
eth: bnxt: store rx buffer size per queue
net: pass queue rx page size from memory provider
net: add bare bone queue configs
net: reduce indent of struct netdev_queue_mgmt_ops members
net: memzero mp params when closing a queue
====================
Link: https://patch.msgid.link/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit 77b9c4a438, reversing
changes made to 4515ec4ad58a37e70a9e1256c0b993958c9b7497:
931420a2fc ("selftests/net: Add netkit container tests")
ab771c938d ("selftests/net: Make NetDrvContEnv support queue leasing")
6be87fbb27 ("selftests/net: Add env for container based tests")
61d99ce3df ("selftests/net: Add bpf skb forwarding program")
920da36341 ("netkit: Add xsk support for af_xdp applications")
eef51113f8 ("netkit: Add netkit notifier to check for unregistering devices")
b5ef109d22 ("netkit: Implement rtnl_link_ops->alloc and ndo_queue_create")
b5c3fa4a0b ("netkit: Add single device mode for netkit")
0073d2fd67 ("xsk: Proxy pool management for leased queues")
1ecea95dd3 ("xsk: Extend xsk_rcv_check validation")
804bf334d0 ("net: Proxy netdev_queue_get_dma_dev for leased queues")
0caa9a8dde ("net: Proxy net_mp_{open,close}_rxq for leased queues")
ff8889ff91 ("net, ethtool: Disallow leased real rxqs to be resized")
9e2103f361 ("net: Add lease info to queue-get response")
31127dedde ("net: Implement netdev_nl_queue_create_doit")
a5546e18f7 ("net: Add queue-create operation")
The series will conflict with io_uring work, and the code needs more
polish.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Implement netdev_nl_queue_create_doit which creates a new rx queue in a
virtual netdev and then leases it to a rx queue in a physical netdev.
Example with ynl client:
# ./pyynl/cli.py \
--spec ~/netlink/specs/netdev.yaml \
--do queue-create \
--json '{"ifindex": 8, "type": "rx", "lease": {"ifindex": 4, "queue": {"type": "rx", "id": 15}}}'
{'id': 1}
Note that the netdevice locking order is always from the virtual to
the physical device.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260115082603.219152-3-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We'll need to pass extra parameters when allocating a queue for memory
providers. Define a new structure for queue configurations, and pass it
to qapi callbacks. It's empty for now, actual parameters will be added
in following patches.
Configurations should persist across resets, and for that they're
default-initialised on device registration and stored in struct
netdev_rx_queue. We also add a new qapi callback for defaulting a given
config. It must be implemented if a driver wants to use queue configs
and is optional otherwise.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
In blamed commit, I added a check against the temporary queue
built in __dev_xmit_skb(). Idea was to drop packets early,
before any spinlock was acquired.
if (unlikely(defer_count > READ_ONCE(q->limit))) {
kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP);
return NET_XMIT_DROP;
}
It turned out that HTB Qdisc has a zero q->limit.
HTB limits packets on a per-class basis.
Some of our tests became flaky.
Add a new sysctl : net.core.qdisc_max_burst to control
how many packets can be stored in the temporary lockless queue.
Also add a new QDISC_BURST_DROP drop reason to better diagnose
future issues.
Thanks Neal !
Fixes: 100dfa74ca ("net: dev_queue_xmit() llist adoption")
Reported-and-bisected-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add missing entries in netdev_lock_type[] and netdev_lock_name[] :
CAN, MCTP, RAWIP, CAIF, IP6GRE, 6LOWPAN, NETLINK, VSOCKMON,
IEEE802154_MONITOR.
Also add a WARN_ONCE() in netdev_lock_pos() to help future bug hunting
next time a protocol is added without updating these arrays.
Fixes: 1a33e10e4a ("net: partially revert dynamic lockdep key changes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260108093244.830280-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some arches (like x86) do not inline spin_unlock_irqrestore().
backlog_unlock_irq_restore() is in RPS/RFS critical path,
we prefer using spin_unlock() + local_irq_restore() for
optimal performance.
Also change backlog_unlock_irq_restore() second argument
to avoid a pointless dereference.
No difference in net/core/dev.o code size.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260105163054.13698-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Aditya Gupta reported PowerPC crashes bisected to the blamed commit.
Apparently some platforms do not allow prefetch() on arbitrary pointers.
prefetch(next);
prefetch(&next->priority); // CRASH when next == NULL
Only NULL seems to be supported, with specific handling in prefetch().
Add a conditional to avoid the two prefetches and the skb->next clearing
for the last skb in the list.
Fixes: b2e9821cff ("net: prefech skb->priority in __dev_xmit_skb()")
Reported-by: Aditya Gupta <adityag@linux.ibm.com>
Closes: https://lore.kernel.org/netdev/e9f4abee-b132-440f-a50e-bced0868b5a7@linux.ibm.com/T/#mddc372b64ec5a3b181acc9ee3909110c391cc18a
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Aditya Gupta <adityag@linux.ibm.com>
Link: https://patch.msgid.link/20251218081844.809008-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Some qdisc like cake, codel, fq_codel might drop packets
in their dequeue() method.
This is currently problematic because dequeue() runs with
the qdisc spinlock held. Freeing skbs can be extremely expensive.
Add qdisc_dequeue_drop() method and a new TCQ_F_DEQUEUE_DROPS
so that these qdiscs can opt-in to defer the skb frees
after the socket spinlock is released.
TCQ_F_DEQUEUE_DROPS is an attempt to not penalize other qdiscs
with an extra cache line miss.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-14-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Using kfree_skb_list_reason() to free list of skbs from qdisc
operations seems wrong as each skb might have a different drop reason.
Cleanup __dev_xmit_skb() to call tcf_kfree_skb_list() once
in preparation of the following patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-13-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Most qdiscs need to read skb->priority at enqueue time().
In commit 100dfa74ca ("net: dev_queue_xmit() llist adoption")
I added a prefetch(next), lets add another one for the second
half of skb.
Note that skb->priority and skb->hash share a common cache line,
so this patch helps qdiscs needing both fields.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-11-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
sch_handle_ingress() sets qdisc_skb_cb(skb)->pkt_len.
We also need to initialize qdisc_skb_cb(skb)->pkt_segs.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-5-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
qdisc_pkt_len_init() is currently initalizing qdisc_skb_cb(skb)->pkt_len.
Add qdisc_skb_cb(skb)->pkt_segs initialization and rename this function
to qdisc_pkt_len_segs_init().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-4-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Qdisc use shinfo->gso_segs for their pkts stats in bstats_update(),
but this field needs to be initialized for SKB_GSO_DODGY users.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-3-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add a new u16 field, next to pkt_len : pkt_segs
This will cache shinfo->gso_segs to speed up qdisc deqeue().
Move slave_dev_queue_mapping at the end of qdisc_skb_cb,
and move three bits from tc_skb_cb :
- post_ct
- post_ct_snat
- post_ct_dnat
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-2-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
skb_defer_free_flush() is becoming more important these days.
Add a prefetch operation to reduce latency a bit on some
platforms like AMD EPYC 7B12.
On more recent cpus, a stall happens when reading skb_shinfo().
Avoiding it will require a more elaborate strategy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20251106085500.2438951-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Revert struct sockaddr from flexible array to fixed 14-byte "sa_data",
to solve over 36,000 -Wflex-array-member-not-at-end warnings, since
struct sockaddr is embedded within many network structs.
With socket/proto sockaddr-based internal APIs switched to use struct
sockaddr_unsized, there should be no more uses of struct sockaddr that
depend on reading beyond the end of struct sockaddr::sa_data that might
trigger bounds checking.
Comparing an x86_64 "allyesconfig" vmlinux build before and after this
patch showed no new "ud1" instructions from CONFIG_UBSAN_BOUNDS nor any
new "field-spanning" memcpy CONFIG_FORTIFY_SOURCE instrumentations.
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-8-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
deliver_skb() should not be inlined as is it not called
in the fast path.
Add unlikely() clauses giving hints to the compiler about this fact.
Before this patch:
size net/core/dev.o
text data bss dec hex filename
121794 13330 176 135300 21084 net/core/dev.o
__netif_receive_skb_core() size on x86_64 : 4080 bytes.
After:
size net/core/dev.o
text data bss dec hex filenamee
120330 13338 176 133844 20ad4 net/core/dev.o
__netif_receive_skb_core() size on x86_64 : 2781 bytes.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251103165256.1712169-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a new state NAPI_STATE_THREADED_BUSY_POLL to the NAPI state enum to
enable and disable threaded busy polling.
When threaded busy polling is enabled for a NAPI, enable
NAPI_STATE_THREADED also.
When the threaded NAPI is scheduled, set NAPI_STATE_IN_BUSY_POLL to
signal napi_complete_done not to rearm interrupts.
Whenever NAPI_STATE_THREADED_BUSY_POLL is unset, the
NAPI_STATE_IN_BUSY_POLL will be unset, napi_complete_done unsets the
NAPI_STATE_SCHED_THREADED bit also, which in turn will make the kthread
go to sleep.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Martin Karsten <mkarsten@uwaterloo.ca>
Tested-by: Martin Karsten <mkarsten@uwaterloo.ca>
Link: https://patch.msgid.link/20251028203007.575686-2-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add the ability to append the incoming IP interface information to
ICMPv6 error messages in accordance with RFC 5837 and RFC 4884. This is
required for more meaningful traceroute results in unnumbered networks.
The feature is disabled by default and controlled via a new sysctl
("net.ipv6.icmp.errors_extension_mask") which accepts a bitmask of ICMP
extensions to append to ICMP error messages. Currently, only a single
value is supported, but the interface and the implementation should be
able to support more extensions, if needed.
Clone the skb and copy the relevant data portions before modifying the
skb as the caller of icmp6_send() still owns the skb after the function
returns. This should be fine since by default ICMP error messages are
rate limited to 1000 per second and no more than 1 per second per
specific host.
Trim or pad the packet to 128 bytes before appending the ICMP extension
structure in order to be compatible with legacy applications that assume
that the ICMP extension structure always starts at this offset (the
minimum length specified by RFC 4884).
Since commit 20e1954fe2 ("ipv6: RFC 4884 partial support for SIT/GRE
tunnels") it is possible for icmp6_send() to be called with an skb that
already contains ICMP extensions. This can happen when we receive an
ICMPv4 message with extensions from a tunnel and translate it to an
ICMPv6 message towards an IPv6 host in the overlay network. I could not
find an RFC that supports this behavior, but it makes sense to not
overwrite the original extensions that were appended to the packet.
Therefore, avoid appending extensions if the length field in the
provided ICMPv6 header is already filled.
Export netdev_copy_name() using EXPORT_IPV6_MOD_GPL() to make it
available to IPv6 when it is built as a module.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251027082232.232571-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add likely() and unlikely() clauses for the common cases:
Device is running.
Queue is not full.
Queue is less than half capacity.
Add max_backlog parameter to skb_flow_limit() to avoid
a second READ_ONCE(net_hotdata.max_backlog).
skb_flow_limit() does not need the backlog_lock protection,
and can be called before we acquire the lock, for even better
resistance to attacks.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251024090517.3289181-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some high level software drivers need to compute features from lower
devices. But each has their own implementations and may lost some
feature compute. Let's use one common function to compute features
for kinds of these devices.
The new helper uses the current bond implementation as the reference
one, as the latter already handles all the relevant aspects: netdev
features, TSO limits and dst retention.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20251017034155.61990-2-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cpus serving NIC interrupts and specifically TX completions are often
trapped in also restarting a busy qdisc (because qdisc was stopped by BQL
or the driver's own flow control).
When they call netdev_tx_completed_queue() or netif_tx_wake_queue(),
they call __netif_schedule() so that the queue can be run
later from net_tx_action() (involving NET_TX_SOFTIRQ)
Quite often, by the time the cpu reaches net_tx_action(), another cpu
grabbed the qdisc spinlock from __dev_xmit_skb(), and we spend too much
time spinning on this lock.
We can detect in __netif_schedule() if a cpu is already at a specific
point in __dev_xmit_skb() where we have the guarantee the queue will
be run.
This patch gives a 13 % increase of throughput on an IDPF NIC (200Gbit),
32 TX qeues, sending UDP packets of 120 bytes.
This also helps __qdisc_run() to not force a NET_TX_SOFTIRQ
if another thread is waiting in __dev_xmit_skb()
Before:
sar -n DEV 5 5|grep eth1|grep Average
Average: eth1 1496.44 52191462.56 210.00 13369396.90 0.00 0.00 0.00 54.76
After:
sar -n DEV 5 5|grep eth1|grep Average
Average: eth1 1457.88 59363099.96 205.08 15206384.35 0.00 0.00 0.00 62.29
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251017145334.3016097-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Remove busylock spinlock and use a lockless list (llist)
to reduce spinlock contention to the minimum.
Idea is that only one cpu might spin on the qdisc spinlock,
while others simply add their skb in the llist.
After this patch, we get a 300 % improvement on heavy TX workloads.
- Sending twice the number of packets per second.
- While consuming 50 % less cycles.
Note that this also allows in the future to submit batches
to various qdisc->enqueue() methods.
Tested:
- Dual Intel(R) Xeon(R) 6985P-C (480 hyper threads).
- 100Gbit NIC, 30 TX queues with FQ packet scheduler.
- echo 64 >/sys/kernel/slab/skbuff_small_head/cpu_partial (avoid contention in mm)
- 240 concurrent "netperf -t UDP_STREAM -- -m 120 -n"
Before:
16 Mpps (41 Mpps if each thread is pinned to a different cpu)
vmstat 2 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
243 0 0 2368988672 51036 1100852 0 0 146 1 242 60 0 9 91 0 0
244 0 0 2368988672 51036 1100852 0 0 536 10 487745 14718 0 52 48 0 0
244 0 0 2368988672 51036 1100852 0 0 512 0 503067 46033 0 52 48 0 0
244 0 0 2368988672 51036 1100852 0 0 512 0 494807 12107 0 52 48 0 0
244 0 0 2368988672 51036 1100852 0 0 702 26 492845 10110 0 52 48 0 0
Lock contention (1 second sample taken on 8 cores)
perf lock record -C0-7 sleep 1; perf lock contention
contended total wait max wait avg wait type caller
442111 6.79 s 162.47 ms 15.35 us spinlock dev_hard_start_xmit+0xcd
5961 9.57 ms 8.12 us 1.60 us spinlock __dev_queue_xmit+0x3a0
244 560.63 us 7.63 us 2.30 us spinlock do_softirq+0x5b
13 25.09 us 3.21 us 1.93 us spinlock net_tx_action+0xf8
If netperf threads are pinned, spinlock stress is very high.
perf lock record -C0-7 sleep 1; perf lock contention
contended total wait max wait avg wait type caller
964508 7.10 s 147.25 ms 7.36 us spinlock dev_hard_start_xmit+0xcd
201 268.05 us 4.65 us 1.33 us spinlock __dev_queue_xmit+0x3a0
12 26.05 us 3.84 us 2.17 us spinlock do_softirq+0x5b
@__dev_queue_xmit_ns:
[256, 512) 21 | |
[512, 1K) 631 | |
[1K, 2K) 27328 |@ |
[2K, 4K) 265392 |@@@@@@@@@@@@@@@@ |
[4K, 8K) 417543 |@@@@@@@@@@@@@@@@@@@@@@@@@@ |
[8K, 16K) 826292 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[16K, 32K) 733822 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
[32K, 64K) 19055 |@ |
[64K, 128K) 17240 |@ |
[128K, 256K) 25633 |@ |
[256K, 512K) 4 | |
After:
29 Mpps (57 Mpps if each thread is pinned to a different cpu)
vmstat 2 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
78 0 0 2369573632 32896 1350988 0 0 22 0 331 254 0 8 92 0 0
75 0 0 2369573632 32896 1350988 0 0 22 50 425713 280199 0 23 76 0 0
104 0 0 2369573632 32896 1350988 0 0 290 0 430238 298247 0 23 76 0 0
86 0 0 2369573632 32896 1350988 0 0 132 0 428019 291865 0 24 76 0 0
90 0 0 2369573632 32896 1350988 0 0 502 0 422498 278672 0 23 76 0 0
perf lock record -C0-7 sleep 1; perf lock contention
contended total wait max wait avg wait type caller
2524 116.15 ms 486.61 us 46.02 us spinlock __dev_queue_xmit+0x55b
5821 107.18 ms 371.67 us 18.41 us spinlock dev_hard_start_xmit+0xcd
2377 9.73 ms 35.86 us 4.09 us spinlock ___slab_alloc+0x4e0
923 5.74 ms 20.91 us 6.22 us spinlock ___slab_alloc+0x5c9
121 3.42 ms 193.05 us 28.24 us spinlock net_tx_action+0xf8
6 564.33 us 167.60 us 94.05 us spinlock do_softirq+0x5b
If netperf threads are pinned (~54 Mpps)
perf lock record -C0-7 sleep 1; perf lock contention
32907 316.98 ms 195.98 us 9.63 us spinlock dev_hard_start_xmit+0xcd
4507 61.83 ms 212.73 us 13.72 us spinlock __dev_queue_xmit+0x554
2781 23.53 ms 40.03 us 8.46 us spinlock ___slab_alloc+0x5c9
3554 18.94 ms 34.69 us 5.33 us spinlock ___slab_alloc+0x4e0
233 9.09 ms 215.70 us 38.99 us spinlock do_softirq+0x5b
153 930.66 us 48.67 us 6.08 us spinlock net_tx_action+0xfd
84 331.10 us 14.22 us 3.94 us spinlock ___slab_alloc+0x5c9
140 323.71 us 9.94 us 2.31 us spinlock ___slab_alloc+0x4e0
@__dev_queue_xmit_ns:
[128, 256) 1539830 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
[256, 512) 2299558 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[512, 1K) 483936 |@@@@@@@@@@ |
[1K, 2K) 265345 |@@@@@@ |
[2K, 4K) 145463 |@@@ |
[4K, 8K) 54571 |@ |
[8K, 16K) 10270 | |
[16K, 32K) 9385 | |
[32K, 64K) 7749 | |
[64K, 128K) 26799 | |
[128K, 256K) 2665 | |
[256K, 512K) 665 | |
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251014171907.3554413-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commits 0f022d32c3
and 44180feacc.
Prior patch in this series implemented loop detection
in act_mirred, we can remove q->owner to save some cycles
in the fast path.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251014171907.3554413-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a followup of commit 726e9e8b94 ("tcp: refine
skb->ooo_okay setting") and of prior commit in this series
("net: control skb->ooo_okay from skb_set_owner_w()")
skb->ooo_okay might never be set for bulk flows that always
have at least one skb in a qdisc queue of NIC queue,
especially if TX completion is delayed because of a stressed cpu.
The so-called "strange attractors" has caused many performance
issues (see for instance 9b462d02d6 ("tcp: TCP Small Queues
and strange attractors")), we need to do better.
We have tried very hard to avoid reorders because TCP was
not dealing with them nicely a decade ago.
Use the new net.core.txq_reselection_ms sysctl to let
flows follow XPS and select a more efficient queue.
After this patch, we no longer have to make sure threads
are pinned to cpus, they now can be migrated without
adding too much spinlock/qdisc/TX completion pressure anymore.
TX completion part was problematic, because it added false sharing
on various socket fields, but also added false sharing and spinlock
contention in mm layers. Calling skb_orphan() from ndo_start_xmit()
is not an option unfortunately.
Note for later:
1) move sk->sk_tx_queue_mapping closer
to sk_tx_queue_mapping_jiffies for better cache locality.
2) Study if 9b462d02d6 ("tcp: TCP Small Queues
and strange attractors") could be revised.
Tested:
Used a host with 32 TX queues, shared by groups of 8 cores.
XPS setup :
echo ff >/sys/class/net/eth1/queue/tx-0/xps_cpus
echo ff00 >/sys/class/net/eth1/queue/tx-1/xps_cpus
echo ff0000 >/sys/class/net/eth1/queue/tx-2/xps_cpus
echo ff000000 >/sys/class/net/eth1/queue/tx-3/xps_cpus
echo ff,00000000 >/sys/class/net/eth1/queue/tx-4/xps_cpus
echo ff00,00000000 >/sys/class/net/eth1/queue/tx-5/xps_cpus
echo ff0000,00000000 >/sys/class/net/eth1/queue/tx-6/xps_cpus
echo ff000000,00000000 >/sys/class/net/eth1/queue/tx-7/xps_cpus
...
Launched a tcp_stream with 15 threads and 1000 flows, initially affined to core 0-15
taskset -c 0-15 tcp_stream -T15 -F1000 -l1000 -c -H target_host
Checked that only queues 0 and 1 are used as instructed by XPS :
tc -s qdisc show dev eth1|grep backlog|grep -v "backlog 0b 0p"
backlog 123489410b 1890p
backlog 69809026b 1064p
backlog 52401054b 805p
Then force each thread to run on cpu 1,9,17,25,33,41,49,57,65,73,81,89,97,105,113,121
C=1;PID=`pidof tcp_stream`;for P in `ls /proc/$PID/task`; do taskset -pc $C $P; C=$(($C + 8));done
Set txq_reselection_ms to 1000
echo 1000 > /proc/sys/net/core/txq_reselection_ms
Check that the flows have migrated nicely:
tc -s qdisc show dev eth1|grep backlog|grep -v "backlog 0b 0p"
backlog 130508314b 1916p
backlog 8584380b 126p
backlog 8584380b 126p
backlog 8379990b 123p
backlog 8584380b 126p
backlog 8487484b 125p
backlog 8584380b 126p
backlog 8448120b 124p
backlog 8584380b 126p
backlog 8720640b 128p
backlog 8856900b 130p
backlog 8584380b 126p
backlog 8652510b 127p
backlog 8448120b 124p
backlog 8516250b 125p
backlog 7834950b 115p
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251013152234.842065-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.
If the device list is too long, this will lock more device mutexes than
lockdep can handle:
unshare -n \
bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by kworker/u16:1/69:
#0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]
Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.
Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.
Fixes: 7e4d784f58 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20251013185052.14021-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Instead of sharing sd->defer_list & sd->defer_count with
many cpus, add one pair for each NUMA node.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250928084934.3266948-4-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Get rid of sd->defer_lock and adopt llist operations.
We optimize skb_attempt_defer_free() for the common case,
where the packet is queued. Otherwise sd->defer_count
is increasing, until skb_defer_free_flush() clears it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250928084934.3266948-3-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This is preparation work to remove the softnet_data.defer_lock,
as it is contended on hosts with large number of cores.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250928084934.3266948-2-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, NETIF_F_TSO_MANGLEID indicates that the inner-most ID can
be mangled. Outer IDs can always be mangled.
Make GSO preserve outer IDs by default, with NETIF_F_TSO_MANGLEID allowing
both inner and outer IDs to be mangled.
This commit also modifies a few drivers that use SKB_GSO_FIXEDID directly.
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250923085908.4687-4-richardbgobert@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Cross-merge networking fixes after downstream PR (net-6.17-rc7).
No conflicts.
Adjacent changes:
drivers/net/ethernet/mellanox/mlx5/core/en/fs.h
9536fbe10c ("net/mlx5e: Add PSP steering in local NIC RX")
7601a0a462 ("net/mlx5e: Add a miss level for ipsec crypto offload")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Provide a callback to validate skb's originating from tcp timewait
socks before passing to the device layer. Full socks have a
sk_validate_xmit_skb member for checking that a device is capable of
performing offloads required for transmitting an skb. With psp, tcp
timewait socks will inherit the crypto state from their corresponding
full socks. Any ACKs or RSTs that originate from a tcp timewait sock
carrying psp state should be psp encapsulated.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250917000954.859376-8-daniel.zahka@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Move definition of sk_validate_xmit_skb() from net/core/sock.c to
net/core/dev.c.
This change is in preparation of the next patch, where
sk_validate_xmit_skb() will need to cast sk to a tcp_timewait_sock *,
and access member fields. Including linux/tcp.h from linux/sock.h
creates a circular dependency, and dev.c is the only current call site
of this function.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250917000954.859376-7-daniel.zahka@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Hosts under DOS attack can suffer from false sharing
in enqueue_to_backlog() : atomic_inc(&sd->dropped).
This is because sd->dropped can be touched from many cpus,
possibly residing on different NUMA nodes.
Generalize the sk_drop_counters infrastucture
added in commit c51613fa27 ("net: add sk->sk_drop_counters")
and use it to replace softnet_data.dropped
with NUMA friendly softnet_data.drop_counters.
This adds 64 bytes per cpu, maybe more in the future
if we increase the number of counters (currently 2)
per 'struct numa_drop_counters'.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250909121942.1202585-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
napi_stop_kthread waits for the NAPI_STATE_SCHED_THREADED to be unset
before stopping the kthread. But it uses test_bit with the
NAPIF_STATE_SCHED_THREADED and that might stop the kthread early before
the flag is unset.
Use the NAPI_* variant of the NAPI state bits in test_bit instead.
Tested:
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
./tools/testing/selftests/drivers/net/napi_threaded.py
TAP version 13
1..2
ok 1 napi_threaded.change_num_queues
ok 2 napi_threaded.enable_dev_threaded_disable_napi_threaded
# Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0
Fixes: 689883de94 ("net: stop napi kthreads when THREADED napi is disabled")
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250910203716.1016546-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
get_rps_cpu() can cache flow_id and hash as both are required by
set_rps_cpu() instead of recalculating them twice.
Signed-off-by: Krishna Kumar <krikku@gmail.com>
Link: https://patch.msgid.link/20250825031005.3674864-3-krikku@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch fixes an issue where two different flows on the same RXq
produce the same hash resulting in continuous flow overwrites.
Flow #1: A packet for Flow #1 comes in, kernel calls the steering
function. The driver gives back a filter id. The kernel saves
this filter id in the selected slot. Later, the driver's
service task checks if any filters have expired and then
installs the rule for Flow #1.
Flow #2: A packet for Flow #2 comes in. It goes through the same steps.
But this time, the chosen slot is being used by Flow #1. The
driver gives a new filter id and the kernel saves it in the
same slot. When the driver's service task runs, it runs through
all the flows, checks if Flow #1 should be expired, the kernel
returns True as the slot has a different filter id, and then
the driver installs the rule for Flow #2.
Flow #1: Another packet for Flow #1 comes in. The same thing repeats.
The slot is overwritten with a new filter id for Flow #1.
This causes a repeated cycle of flow programming for missed packets,
wasting CPU cycles while not improving performance. This problem happens
at higher rates when the RPS table is small, but tests show it still
happens even with 12,000 connections and an RPS size of 16K per queue
(global table size = 144x16K = 64K).
This patch prevents overwriting an rps_dev_flow entry if it is active.
The intention is that it is better to do aRFS for the first flow instead
of hurting all flows on the same hash. Without this, two (or more) flows
on one RX queue with the same hash can keep overwriting each other. This
causes the driver to reprogram the flow repeatedly.
Changes:
1. Add a new 'hash' field to struct rps_dev_flow.
2. Add rps_flow_is_active(): a helper function to check if a flow is
active or not, extracted from rps_may_expire_flow(). It is further
simplified as per reviewer feedback.
3. In set_rps_cpu():
- Avoid overwriting by programming a new filter if:
- The slot is not in use, or
- The slot is in use but the flow is not active, or
- The slot has an active flow with the same hash, but target CPU
differs.
- Save the hash in the rps_dev_flow entry.
4. rps_may_expire_flow(): Use earlier extracted rps_flow_is_active().
Testing & results:
- Driver: ice (E810 NIC), Kernel: net-next
- #CPUs = #RXq = 144 (1:1)
- Number of flows: 12K
- Eight RPS settings from 256 to 32768. Though RPS=256 is not ideal,
it is still sufficient to cover 12K flows (256*144 rx-queues = 64K
global table slots)
- Global Table Size = 144 * RPS (effectively equal to 256 * RPS)
- Each RPS test duration = 8 mins (org code) + 8 mins (new code).
- Metrics captured on client
Legend for following tables:
Steer-C: #times ndo_rx_flow_steer() was Called by set_rps_cpu()
Steer-L: #times ice_arfs_flow_steer() Looped over aRFS entries
Add: #times driver actually programmed aRFS (ice_arfs_build_entry())
Del: #times driver deleted the flow (ice_arfs_del_flow_rules())
Units: K = 1,000 times, M = 1 million times
|-------|---------|------| Org Code |---------|---------|
| RPS | Latency | CPU | Add | Del | Steer-C | Steer-L |
|-------|---------|------|--------|--------|---------|---------|
| 256 | 227.0 | 93.2 | 1.6M | 1.6M | 121.7M | 267.6M |
| 512 | 225.9 | 94.1 | 11.5M | 11.2M | 65.7M | 199.6M |
| 1024 | 223.5 | 95.6 | 16.5M | 16.5M | 27.1M | 187.3M |
| 2048 | 222.2 | 96.3 | 10.5M | 10.5M | 12.5M | 115.2M |
| 4096 | 223.9 | 94.1 | 5.5M | 5.5M | 7.2M | 65.9M |
| 8192 | 224.7 | 92.5 | 2.7M | 2.7M | 3.0M | 29.9M |
| 16384 | 223.5 | 92.5 | 1.3M | 1.3M | 1.4M | 13.9M |
| 32768 | 219.6 | 93.2 | 838.1K | 838.1K | 965.1K | 8.9M |
|-------|---------|------| New Code |---------|---------|
| 256 | 201.5 | 99.1 | 13.4K | 5.0K | 13.7K | 75.2K |
| 512 | 202.5 | 98.2 | 11.2K | 5.9K | 11.2K | 55.5K |
| 1024 | 207.3 | 93.9 | 11.5K | 9.7K | 11.5K | 59.6K |
| 2048 | 207.5 | 96.7 | 11.8K | 11.1K | 15.5K | 79.3K |
| 4096 | 206.9 | 96.6 | 11.8K | 11.7K | 11.8K | 63.2K |
| 8192 | 205.8 | 96.7 | 11.9K | 11.8K | 11.9K | 63.9K |
| 16384 | 200.9 | 98.2 | 11.9K | 11.9K | 11.9K | 64.2K |
| 32768 | 202.5 | 98.0 | 11.9K | 11.9K | 11.9K | 64.2K |
|-------|---------|------|--------|--------|---------|---------|
Some observations:
1. Overall Latency improved: (1790.19-1634.94)/1790.19*100 = 8.67%
2. Overall CPU increased: (777.32-751.49)/751.45*100 = 3.44%
3. Flow Management (add/delete) remained almost constant at ~11K
compared to values in millions.
Signed-off-by: Krishna Kumar <krikku@gmail.com>
Link: https://patch.msgid.link/20250825031005.3674864-2-krikku@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When performing Generic Segmentation Offload (GSO) on an IPv6 packet that
contains extension headers, the kernel incorrectly requests checksum offload
if the egress device only advertises NETIF_F_IPV6_CSUM feature, which has
a strict contract: it supports checksum offload only for plain TCP or UDP
over IPv6 and explicitly does not support packets with extension headers.
The current GSO logic violates this contract by failing to disable the feature
for packets with extension headers, such as those used in GREoIPv6 tunnels.
This violation results in the device being asked to perform an operation
it cannot support, leading to a `skb_warn_bad_offload` warning and a collapse
of network throughput. While device TSO/USO is correctly bypassed in favor
of software GSO for these packets, the GSO stack must be explicitly told not
to request checksum offload.
Mask NETIF_F_IPV6_CSUM, NETIF_F_TSO6 and NETIF_F_GSO_UDP_L4
in gso_features_check if the IPv6 header contains extension headers to compute
checksum in software.
The exception is a BIG TCP extension, which, as stated in commit
68e068cabd ("net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets"):
"The feature is only enabled on devices that support BIG TCP TSO.
The header is only present for PF_PACKET taps like tcpdump,
and not transmitted by physical devices."
kernel log output (truncated):
WARNING: CPU: 1 PID: 5273 at net/core/dev.c:3535 skb_warn_bad_offload+0x81/0x140
...
Call Trace:
<TASK>
skb_checksum_help+0x12a/0x1f0
validate_xmit_skb+0x1a3/0x2d0
validate_xmit_skb_list+0x4f/0x80
sch_direct_xmit+0x1a2/0x380
__dev_xmit_skb+0x242/0x670
__dev_queue_xmit+0x3fc/0x7f0
ip6_finish_output2+0x25e/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_tnl_xmit+0x608/0xc00 [ip6_tunnel]
ip6gre_tunnel_xmit+0x1c0/0x390 [ip6_gre]
dev_hard_start_xmit+0x63/0x1c0
__dev_queue_xmit+0x6d0/0x7f0
ip6_finish_output2+0x214/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
inet6_csk_xmit+0xeb/0x150
__tcp_transmit_skb+0x555/0xa80
tcp_write_xmit+0x32a/0xe90
tcp_sendmsg_locked+0x437/0x1110
tcp_sendmsg+0x2f/0x50
...
skb linear: 00000000: e4 3d 1a 7d ec 30 e4 3d 1a 7e 5d 90 86 dd 60 0e
skb linear: 00000010: 00 0a 1b 34 3c 40 20 11 00 00 00 00 00 00 00 00
skb linear: 00000020: 00 00 00 00 00 12 20 11 00 00 00 00 00 00 00 00
skb linear: 00000030: 00 00 00 00 00 11 2f 00 04 01 04 01 01 00 00 00
skb linear: 00000040: 86 dd 60 0e 00 0a 1b 00 06 40 20 23 00 00 00 00
skb linear: 00000050: 00 00 00 00 00 00 00 00 00 12 20 23 00 00 00 00
skb linear: 00000060: 00 00 00 00 00 00 00 00 00 11 bf 96 14 51 13 f9
skb linear: 00000070: ae 27 a0 a8 2b e3 80 18 00 40 5b 6f 00 00 01 01
skb linear: 00000080: 08 0a 42 d4 50 d5 4b 70 f8 1a
Fixes: 04c20a9356 ("net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension")
Reported-by: Tianhao Zhao <tizhao@redhat.com>
Suggested-by: Michal Schmidt <mschmidt@redhat.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Jakub Ramaseuski <jramaseu@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250814105119.1525687-1-jramaseu@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The following order of calls currently deadlocks if:
- device has threaded=1; and
- NAPI has persistent config with threaded=0.
netif_napi_add_weight_config()
dev->threaded == 1
napi_kthread_create()
napi_enable()
napi_restore_config()
napi_set_threaded(0)
napi_stop_kthread()
while (NAPIF_STATE_SCHED)
msleep(20)
We deadlock because disabled NAPI has STATE_SCHED set.
Creating a thread in netif_napi_add() just to destroy it in
napi_disable() is fairly ugly in the first place. Let's read
both the device config and the NAPI config in netif_napi_add().
Fixes: e6d7626881 ("net: Update threaded state in napi config in netif_set_threaded")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250809001205.1147153-4-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We have to make sure that all future NAPIs will have the right threaded
state when the state is configured on the device level.
We chose not to have an "unset" state for threaded, and not to wipe
the NAPI config clean when channels are explicitly disabled.
This means the persistent config structs "exist" even when their NAPIs
are not instantiated.
Differently put - the NAPI persistent state lives in the net_device
(ncfg == struct napi_config):
,--- [napi 0] - [napi 1]
[dev] | |
`--- [ncfg 0] - [ncfg 1]
so say we a device with 2 queues but only 1 enabled:
,--- [napi 0]
[dev] |
`--- [ncfg 0] - [ncfg 1]
now we set the device to threaded=1:
,---------- [napi 0 (thr:1)]
[dev(thr:1)] |
`---------- [ncfg 0 (thr:1)] - [ncfg 1 (thr:?)]
Since [ncfg 1] was not attached to a NAPI during configuration we
skipped it. If we create a NAPI for it later it will have the old
setting (presumably disabled). One could argue if this is right
or not "in principle", but it's definitely not how things worked
before per-NAPI config..
Fixes: 2677010e77 ("Add support to set NAPI threaded for individual NAPI")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250809001205.1147153-3-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Commit 2677010e77 ("Add support to set NAPI threaded for individual
NAPI") added support to enable/disable threaded napi using netlink. This
also extended the napi config save/restore functionality to set the napi
threaded state. This breaks netdev reset for drivers that use napi
threaded at device level and also use napi config save/restore on
napi_disable/napi_enable. Basically on netdev with napi threaded enabled
at device level, a napi_enable call will get stuck trying to stop the
napi kthread. This is because the napi->config->threaded is set to
disabled when threaded is enabled at device level.
The issue can be reproduced on virtio-net device using qemu. To
reproduce the issue run following,
echo 1 > /sys/class/net/threaded
ethtool -L eth0 combined 1
Update the threaded state in napi config in netif_set_threaded and add a
new test that verifies this scenario.
Tested on qemu with virtio-net:
NETIF=eth0 ./tools/testing/selftests/drivers/net/napi_threaded.py
TAP version 13
1..2
ok 1 napi_threaded.change_num_queues
ok 2 napi_threaded.enable_dev_threaded_disable_napi_threaded
# Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0
Fixes: 2677010e77 ("Add support to set NAPI threaded for individual NAPI")
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250804164457.2494390-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
Instead of using '0' and '1' for napi threaded state use an enum with
'disabled' and 'enabled' states.
Tested:
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-4-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Prepare for adding an enum type for NAPI threaded states by adding
netif_threaded_enable API. De-export the existing netif_set_threaded API
and only use it internally. Update existing drivers to use
netif_threaded_enable instead of the de-exported netif_set_threaded.
Note that dev_set_threaded used by mt76 debugfs file is unchanged.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-3-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move multiple copies of same code snippet doing `gro_flush` and
`gro_normal_list` into separate helper function.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-2-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_close_many is used only by vlan/dsa and one mtk driver, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-8-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Note that one dev_set_threaded call still remains in mt76 for debugfs file.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-7-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-6-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
__netif_set_mtu is used only by bond, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-5-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_pre_changeaddr_notify is used only by ipvlan/bond, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_get_mac_address is used only by tun/tap, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-3-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a new SKB drop reason (SKB_DROP_REASON_PFMEMALLOC) to track packets
dropped due to memory pressure. In production environments, we've observed
memory exhaustion reported by memory layer stack traces, but these drops
were not properly tracked in the SKB drop reason infrastructure.
While most network code paths now properly report pfmemalloc drops, some
protocol-specific socket implementations still use sk_filter() without
drop reason tracking:
- Bluetooth L2CAP sockets
- CAIF sockets
- IUCV sockets
- Netlink sockets
- SCTP sockets
- Unix domain sockets
These remaining cases represent less common paths and could be converted
in a follow-up patch if needed. The current implementation provides
significantly improved observability into memory pressure events in the
network stack, especially for key protocols like TCP and UDP, helping to
diagnose problems in production environments.
Reported-by: Matt Fleming <mfleming@cloudflare.com>
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/175268316579.2407873.11634752355644843509.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A net device has a threaded sysctl that can be used to enable threaded
NAPI polling on all of the NAPI contexts under that device. Allow
enabling threaded NAPI polling at individual NAPI level using netlink.
Extend the netlink operation `napi-set` and allow setting the threaded
attribute of a NAPI. This will enable the threaded polling on a NAPI
context.
Add a test in `nl_netdev.py` that verifies various cases of threaded
NAPI being set at NAPI and at device level.
Tested
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250710211203.3979655-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a follow-up for commit eb1ac9ff6c ("ipv6: anycast: Don't
hold RTNL for IPV6_JOIN_ANYCAST.").
We should not add a new device lookup API without netdevice_tracker.
Let's pass netdevice_tracker to dev_get_by_flags_rcu() and rename it
with netdev_ prefix to match other newer APIs.
Note that we always use GFP_ATOMIC for netdev_hold() as it's expected
to be called under RCU.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/netdev/20250708184053.102109f6@kernel.org/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250711051120.2866855-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Attach_type will be set when a link is created by user. It is better to
record attach_type in bpf_link generically and have it available
universally for all link types. So add the attach_type field in bpf_link
and move the sleepable field to avoid unnecessary gap padding.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev
inet6_sk(sk)->ipv6_ac_list is protected by lock_sock().
In ipv6_sock_ac_join(), only __dev_get_by_index(), __dev_get_by_flags(),
and __in6_dev_get() require RTNL.
__dev_get_by_flags() is only used by ipv6_sock_ac_join() and can be
converted to RCU version.
Let's replace RCU version helper and drop RTNL from IPV6_JOIN_ANYCAST.
setsockopt_needs_rtnl() will be removed in the next patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250702230210.3115355-15-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All drivers are now converted to dedicated _rxfh_context ops.
Remove the use of >set_rxfh() to manage additional contexts.
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20250707184115.2285277-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Refine qdisc_pkt_len_init to include headers up through
the inner transport header when computing header size
for encapsulations. Also refine net/sched/sch_cake.c
borrowed from qdisc_pkt_len_init().
Signed-off-by: Fengyuan Gong <gfengyuan@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250702160741.1204919-1-gfengyuan@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MSG_ZEROCOPY data must be copied before data is queued to local
sockets, to avoid indefinite timeout until memory release.
This test is performed by skb_orphan_frags_rx, which is called when
looping an egress skb to packet sockets, error queue or ingress path.
To preserve zerocopy for skbs that are looped to ingress but are then
forwarded to an egress device rather than delivered locally, defer
this last check until an skb enters the local IP receive path.
This is analogous to existing behavior of skb_clear_delivery_time.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630194312.1571410-2-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now that we have dentries and the ability to create meaningful symlinks
to them, don't keep a name string in each tracker. Switch the output
format to print "class@address", and drop the name field.
Also, add a kerneldoc header for ref_tracker_dir_init().
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20250618-reftrack-dbgfs-v15-9-24fc37ead144@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A later patch in the series will be adding debugfs files for each
ref_tracker that get created in ref_tracker_dir_init(). The format will
be "class@%px". The current "name" string can vary between
ref_tracker_dir objects of the same type, so it's not suitable for this
purpose.
Add a new "class" string to the ref_tracker dir that describes the
the type of object (sans any individual info for that object).
Also, in the i915 driver, gate the creation of debugfs files on whether
the dentry pointer is still set to NULL. CI has shown that the
ref_tracker_dir can be initialized more than once.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20250618-reftrack-dbgfs-v15-4-24fc37ead144@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The existing netdev_ops_assert_locked() already asserts that either
the RTNL lock or the per-device lock is held, making the explicit
ASSERT_RTNL() redundant.
Cc: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250616162117.287806-5-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Drivers that are using ops lock and don't depend on RTNL lock
still need to manage it because udp_tunnel's RTNL dependency.
Introduce new udp_tunnel_nic_lock and use it instead of
rtnl_lock. Drop non-UDP_TUNNEL_NIC_INFO_MAY_SLEEP mode from
udp_tunnel infra (udp_tunnel_nic_device_sync_work needs to
grab udp_tunnel_nic_lock mutex and might sleep).
Cover more places in v4:
- netlink
- udp_tunnel_notify_add_rx_port (ndo_open)
- triggers udp_tunnel_nic_device_sync_work
- udp_tunnel_notify_del_rx_port (ndo_stop)
- triggers udp_tunnel_nic_device_sync_work
- udp_tunnel_get_rx_info (__netdev_update_features)
- triggers NETDEV_UDP_TUNNEL_PUSH_INFO
- udp_tunnel_drop_rx_info (__netdev_update_features)
- triggers NETDEV_UDP_TUNNEL_DROP_INFO
- udp_tunnel_nic_reset_ntf (ndo_open)
- notifiers
- udp_tunnel_nic_netdevice_event, depending on the event:
- triggers NETDEV_UDP_TUNNEL_PUSH_INFO
- triggers NETDEV_UDP_TUNNEL_DROP_INFO
- ethnl_tunnel_info_reply_size
- udp_tunnel_nic_set_port_priv (two intel drivers)
Cc: Michael Chan <michael.chan@broadcom.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250616162117.287806-4-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Once the THREADED napi is disabled, the napi kthread should also be
stopped. Keeping the kthread intact after disabling THREADED napi makes
the PID of this kthread show up in the output of netlink 'napi-get' and
ps -ef output.
The is discussed in the patch below:
https://lore.kernel.org/all/20250502191548.559cc416@kernel.org
NAPI kthread should stop only if,
- There are no pending napi poll scheduled for this thread.
- There are no new napi poll scheduled for this thread while it has
stopped.
- The ____napi_schedule can correctly fallback to the softirq for napi
polling.
Since napi_schedule_prep provides mutual exclusion over STATE_SCHED bit,
it is safe to unset the STATE_THREADED when SCHED_THREADED is set or the
SCHED bit is not set. SCHED_THREADED being set means that SCHED is
already set and the kthread owns this napi.
To disable threaded napi, unset STATE_THREADED bit safely if
SCHED_THREADED is set or SCHED is unset. Once STATE_THREADED is unset
safely then wait for the kthread to unset the SCHED_THREADED bit so it
safe to stop the kthread.
Add a new test in nl_netdev to verify this behaviour.
Tested:
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..6
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.nsim_rxq_reset_down
# Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
Ran neper for 300 seconds and did enable/disable of thread napi in a
loop continuously.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250609173015.3851695-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
from_cleanup_net() reads cleanup_net_task locklessly.
Add READ_ONCE()/WRITE_ONCE() annotations to avoid
a potential KCSAN warning, even if the race is harmless.
Fixes: 0734d7c3d9 ("net: expedite synchronize_net() for cleanup_net()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20250604093928.1323333-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The MANA driver's probe registers netdevice via the following call chain:
mana_probe()
register_netdev()
register_netdevice()
register_netdevice() calls notifier callback for netvsc driver,
holding the netdev mutex via netdev_lock_ops().
Further this netvsc notifier callback end up attempting to acquire the
same lock again in dev_xdp_propagate() leading to deadlock.
netvsc_netdev_event()
netvsc_vf_setxdp()
dev_xdp_propagate()
This deadlock was not observed so far because net_shaper_ops was never set,
and thus the lock was effectively a no-op in this case. Fix this by using
netif_xdp_propagate() instead of dev_xdp_propagate() to avoid recursive
locking in this path.
And, since no deadlock is observed on the other path which is via
netvsc_probe, add the lock exclusivly for that path.
Also, clean up the unregistration path by removing the unnecessary call to
netvsc_vf_setxdp(), since unregister_netdevice_many_notify() already
performs this cleanup via dev_xdp_uninstall().
Fixes: 97246d6d21 ("net: hold netdev instance lock during ndo_bpf")
Cc: stable@vger.kernel.org
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Tested-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://patch.msgid.link/1748513910-23963-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All users of dev_set_mac_address() are now using a struct sockaddr_storage.
Convert the internal data type to struct sockaddr_storage, drop the casts,
and update pointer types.
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20250521204619.2301870-6-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In order to avoid passing around struct sockaddr that has a size the
compiler cannot reason about (nor track at runtime), convert
netif_set_mac_address() to take struct sockaddr_storage. This is just a
cast conversion, so there is are no binary changes. Following patches
will make actual allocation changes.
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20250521204619.2301870-2-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Instead of calling __skb_checksum() with a skb_checksum_ops struct that
does CRC32C, just call the new function skb_crc32c(). This is faster
and simpler.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20250519175012.36581-4-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a hidden kconfig symbol NET_CRC32C that will group together the
functions that calculate CRC32C checksums of packets, so that these
don't have to be built into NET-enabled kernels that don't need them.
Make skb_crc32c_csum_help() (which is called only when IP_SCTP is
enabled) conditional on this symbol, and make IP_SCTP select it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20250519175012.36581-2-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cover three recent cases:
1. missing ops locking for the lowers during netdev_sync_lower_features
2. missing locking for dev_set_promiscuity (plus netdev_ops_assert_locked
with a comment on why/when it's needed)
3. rcu lock during team_change_rx_flags
Verified that each one triggers when the respective fix is reverted.
Not sure about the placement, but since it all relies on teaming,
added to the teaming directory.
One ugly bit is that I add NETIF_F_LRO to netdevsim; there is no way
to trigger netdev_sync_lower_features without it.
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250516232205.539266-1-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
system_page_pool is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.
Make a struct with a page_pool member (original system_page_pool) and a
local_lock_t and use local_lock_nested_bh() for locking. This change
adds only lockdep coverage and does not alter the functional behaviour
for !PREEMPT_RT.
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-6-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We should not enable netmem TX for drivers that don't declare support.
Check for driver netmem TX support during devmem TX binding and fail if
the driver does not have the functionality.
Check for driver support in validate_xmit_skb as well.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250508004830.4100853-9-almasrymina@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
__netdev_update_features() expects the netdevice to be ops-locked, but
it gets called recursively on the lower level netdevices to sync their
features, and nothing locks those.
This commit fixes that, with the assumption that it shouldn't be possible
for both higher-level and lover-level netdevices to require the instance
lock, because that would lead to lock dependency warnings.
Without this, playing with higher level (e.g. vxlan) netdevices on top
of netdevices with instance locking enabled can run into issues:
WARNING: CPU: 59 PID: 206496 at ./include/net/netdev_lock.h:17 netif_napi_add_weight_locked+0x753/0xa60
[...]
Call Trace:
<TASK>
mlx5e_open_channel+0xc09/0x3740 [mlx5_core]
mlx5e_open_channels+0x1f0/0x770 [mlx5_core]
mlx5e_safe_switch_params+0x1b5/0x2e0 [mlx5_core]
set_feature_lro+0x1c2/0x330 [mlx5_core]
mlx5e_handle_feature+0xc8/0x140 [mlx5_core]
mlx5e_set_features+0x233/0x2e0 [mlx5_core]
__netdev_update_features+0x5be/0x1670
__netdev_update_features+0x71f/0x1670
dev_ethtool+0x21c5/0x4aa0
dev_ioctl+0x438/0xae0
sock_ioctl+0x2ba/0x690
__x64_sys_ioctl+0xa78/0x1700
do_syscall_64+0x6d/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
Fixes: 7e4d784f58 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250509072850.2002821-1-cratiu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Accidentally spotted while trying to understand what else needs
to be renamed to netif_ prefix. Most of the calls to dev_set_promiscuity
are adjacent to dev_set_allmulti or dev_disable_lro so it should
be safe to add the lock. Note that new netif_set_promiscuity is
currently unused, the locked paths call __dev_set_promiscuity directly.
Fixes: ad7c7b2172 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250506011919.2882313-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
__qdisc_destroy() calls into various qdiscs .destroy() op, which in turn
can call .ndo_setup_tc(), which requires the netdev instance lock.
This commit extends the critical section in
unregister_netdevice_many_notify() to cover dev_shutdown() (and
dev_tcx_uninstall() as a side-effect) and acquires the netdev instance
lock in __dev_change_net_namespace() for the other dev_shutdown() call.
This should now guarantee that for all qdisc ops, the netdev instance
lock is held during .ndo_setup_tc().
Fixes: a0527ee2df ("net: hold netdev instance lock during qdisc ndo_setup_tc")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250505194713.1723399-1-cratiu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We need to be careful when operating on dev while in rtnl_create_link().
Some devices (vxlan) initialize netdev_ops in ->newlink, so later on.
Avoid using netdev_lock_ops(), the device isn't registered so we
cannot legally call its ops or generate any notifications for it.
netdev_ops_assert_locked_or_invisible() is safe to use, it checks
registration status first.
Reported-by: syzbot+de1c7d68a10e3f123bdd@syzkaller.appspotmail.com
Fixes: 04efcee6ef ("net: hold instance lock during NETDEV_CHANGE")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250415151552.768373-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdevice reg_state was split into two 16 bit enums back in 2010
in commit a2835763e1 ("rtnetlink: handle rtnl_link netlink
notifications manually"). Since the split the fields have been
moved apart, and last year we converted reg_state to a normal
u8 in commit 4d42b37def ("net: convert dev->reg_state to u8").
rtnl_link_state being a 16 bitfield makes no sense. Convert it
to a single bool, it seems very unlikely after 15 years that
we'll need more values in it.
We could drop dev->rtnl_link_ops from the conditions but feels
like having it there more clearly points at the reason for this
hack.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250410014246.780885-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Lockdep found the following dependency:
&dev_instance_lock_key#3 -->
&rdev->wiphy.mtx -->
&net->xdp.lock -->
&xs->mutex -->
&dev_instance_lock_key#3
The first dependency is the problem. wiphy mutex should be outside
the instance locks. The problem happens in notifiers (as always)
for CLOSE. We only hold the instance lock for ops locked devices
during CLOSE, and WiFi netdevs are not ops locked. Unfortunately,
when we dev_close_many() during netns dismantle we may be holding
the instance lock of _another_ netdev when issuing a CLOSE for
a WiFi device.
Lockdep's "Possible unsafe locking scenario" only prints 3 locks
and we have 4, plus I think we'd need 3 CPUs, like this:
CPU0 CPU1 CPU2
---- ---- ----
lock(&xs->mutex);
lock(&dev_instance_lock_key#3);
lock(&rdev->wiphy.mtx);
lock(&net->xdp.lock);
lock(&xs->mutex);
lock(&rdev->wiphy.mtx);
lock(&dev_instance_lock_key#3);
Tho, I don't think that's possible as CPU1 and CPU2 would
be under rtnl_lock. Even if we have per-netns rtnl_lock and
wiphy can span network namespaces - CPU0 and CPU1 must be
in the same netns to see dev_instance_lock, so CPU0 can't
be installing a socket as CPU1 is tearing the netns down.
Regardless, our expected lock ordering is that wiphy lock
is taken before instance locks, so let's fix this.
Go over the ops locked and non-locked devices separately.
Note that calling dev_close_many() on an empty list is perfectly
fine. All processing (including RCU syncs) are conditional
on the list not being empty, already.
Fixes: 7e4d784f58 ("net: hold netdev instance lock during rtnetlink operations")
Reported-by: syzbot+6f588c78bf765b62b450@syzkaller.appspotmail.com
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250412233011.309762-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add helpers to "lock a netdev in a backward-compatible way",
which for ops-locked netdevs will mean take the instance lock.
For drivers which haven't opted into the ops locking we'll take
rtnl_lock.
The scoped foreach is dropping and re-taking the lock for each
device, even if prev and next are both under rtnl_lock.
I hope that's fine since we expect that netdev nl to be mostly
supported by modern drivers, and modern drivers should also
opt into the instance locking.
Note that these helpers are mostly needed for queue related state,
because drivers modify queue config in their ops in a non-atomic
way. Or differently put, queue changes don't have a clear-cut API
like NAPI configuration. Any state that can should just use the
instance lock directly, not the "compat" hacks.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250408195956.412733-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
