| Age | Commit message (Collapse) | Author | Files | Lines |
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For the drivers that use shaper API, switch to the mode where
core stack holds the netdev lock. This affects two drivers:
* iavf - already grabs netdev lock in ndo_open/ndo_stop, so mostly
remove these
* netdevsim - switch to _locked APIs to avoid deadlock
iavf_close diff is a bit confusing, the existing call looks like this:
iavf_close() {
netdev_lock()
..
netdev_unlock()
wait_event_timeout(down_waitqueue)
}
I change it to the following:
netdev_lock()
iavf_close() {
..
netdev_unlock()
wait_event_timeout(down_waitqueue)
netdev_lock() // reusing this lock call
}
netdev_unlock()
Since I'm reusing existing netdev_lock call, so it looks like I only
add netdev_unlock.
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The cpu_rmap_put() will call kfree() when the last reference is dropped
so it could result in a use after free when we dereference the same
pointer the next line. Move the cpu_rmap_put() after the dereference.
Fixes: bd7c00605ee0 ("net: move aRFS rmap management and CPU affinity to core")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/5a9c53a4-5487-4b8c-9ffa-d8e5343aaaaf@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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It could be hard to understand why the netlink command fails. For example,
if dev->netns_immutable is set, the error is "Invalid argument".
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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The name 'netns_local' is confusing. A following commit will export it via
netlink, so let's use a more explicit name.
Reported-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Cross-merge networking fixes after downstream PR (net-6.14-rc5).
Conflicts:
drivers/net/ethernet/cadence/macb_main.c
fa52f15c745c ("net: cadence: macb: Synchronize stats calculations")
75696dd0fd72 ("net: cadence: macb: Convert to get_stats64")
https://lore.kernel.org/20250224125848.68ee63e5@canb.auug.org.au
Adjacent changes:
drivers/net/ethernet/intel/ice/ice_sriov.c
79990cf5e7ad ("ice: Fix deinitializing VF in error path")
a203163274a4 ("ice: simplify VF MSI-X managing")
net/ipv4/tcp.c
18912c520674 ("tcp: devmem: don't write truncated dmabuf CMSGs to userspace")
297d389e9e5b ("net: prefix devmem specific helpers")
net/mptcp/subflow.c
8668860b0ad3 ("mptcp: reset when MPTCP opts are dropped after join")
c3349a22c200 ("mptcp: consolidate subflow cleanup")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Make GRO init and cleanup functions global to be able to use GRO
without a NAPI instance. Taking into account already global gro_flush(),
it's now fully usable standalone.
New functions are not exported, since they're not supposed to be used
outside of the kernel core code.
Tested-by: Daniel Xu <dxu@dxuuu.xyz>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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In fact, these two are not tied closely to each other. The only
requirements to GRO are to use it in the BH context and have some
sane limits on the packet batches, e.g. NAPI has a limit of its
budget (64/8/etc.).
Move purely GRO fields into a new structure, &gro_node. Embed it
into &napi_struct and adjust all the references.
gro_node::cached_napi_id is effectively the same as
napi_struct::napi_id, but to be used on GRO hotpath to mark skbs.
napi_struct::napi_id is now a fully control path field.
Three Ethernet drivers use napi_gro_flush() not really meant to be
exported, so move it to <net/gro.h> and add that include there.
napi_gro_receive() is used in more than 100 drivers, keep it
in <linux/netdevice.h>.
This does not make GRO ready to use outside of the NAPI context
yet.
Tested-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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A common task for most drivers is to remember the user-set CPU affinity
to its IRQs. On each netdev reset, the driver should re-assign the user's
settings to the IRQs. Unify this task across all drivers by moving the CPU
affinity to napi->config.
However, to move the CPU affinity to core, we also need to move aRFS
rmap management since aRFS uses its own IRQ notifiers.
For the aRFS, add a new netdev flag "rx_cpu_rmap_auto". Drivers supporting
aRFS should set the flag via netif_enable_cpu_rmap() and core will allocate
and manage the aRFS rmaps. Freeing the rmap is also done by core when the
netdev is freed. For better IRQ affinity management, move the IRQ rmap
notifier inside the napi_struct and add new notify.notify and
notify.release functions: netif_irq_cpu_rmap_notify() and
netif_napi_affinity_release().
Now we have the aRFS rmap management in core, add CPU affinity mask to
napi_config. To delegate the CPU affinity management to the core, drivers
must:
1 - set the new netdev flag "irq_affinity_auto":
netif_enable_irq_affinity(netdev)
2 - create the napi with persistent config:
netif_napi_add_config()
3 - bind an IRQ to the napi instance: netif_napi_set_irq()
the core will then make sure to use re-assign affinity to the napi's
IRQ.
The default IRQ mask is set to one cpu starting from the closest NUMA.
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://patch.msgid.link/20250224232228.990783-2-ahmed.zaki@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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napi_schedule() is expected to be called either:
* From an interrupt, where raised softirqs are handled on IRQ exit
* From a softirq disabled section, where raised softirqs are handled on
the next call to local_bh_enable().
* From a softirq handler, where raised softirqs are handled on the next
round in do_softirq(), or further deferred to a dedicated kthread.
Other bare tasks context may end up ignoring the raised NET_RX vector
until the next random softirq handling opportunity, which may not
happen before a while if the CPU goes idle afterwards with the tick
stopped.
Such "misuses" have been detected on several places thanks to messages
of the kind:
"NOHZ tick-stop error: local softirq work is pending, handler #08!!!"
For example:
__raise_softirq_irqoff
__napi_schedule
rtl8152_runtime_resume.isra.0
rtl8152_resume
usb_resume_interface.isra.0
usb_resume_both
__rpm_callback
rpm_callback
rpm_resume
__pm_runtime_resume
usb_autoresume_device
usb_remote_wakeup
hub_event
process_one_work
worker_thread
kthread
ret_from_fork
ret_from_fork_asm
And also:
* drivers/net/usb/r8152.c::rtl_work_func_t
* drivers/net/netdevsim/netdev.c::nsim_start_xmit
There is a long history of issues of this kind:
019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()")
330068589389 ("idpf: disable local BH when scheduling napi for marker packets")
e3d5d70cb483 ("net: lan78xx: fix "softirq work is pending" error")
e55c27ed9ccf ("mt76: mt7615: add missing bh-disable around rx napi schedule")
c0182aa98570 ("mt76: mt7915: add missing bh-disable around tx napi enable/schedule")
970be1dff26d ("mt76: disable BH around napi_schedule() calls")
019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()")
30bfec4fec59 ("can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt")
e63052a5dd3c ("mlx5e: add add missing BH locking around napi_schdule()")
83a0c6e58901 ("i40e: Invoke softirqs after napi_reschedule")
bd4ce941c8d5 ("mlx4: Invoke softirqs after napi_reschedule")
8cf699ec849f ("mlx4: do not call napi_schedule() without care")
ec13ee80145c ("virtio_net: invoke softirqs after __napi_schedule")
This shows that relying on the caller to arrange a proper context for
the softirqs to be handled while calling napi_schedule() is very fragile
and error prone. Also fixing them can also prove challenging if the
caller may be called from different kinds of contexts.
Therefore fix this from napi_schedule() itself with waking up ksoftirqd
when softirqs are raised from task contexts.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reported-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Francois Romieu <romieu@fr.zoreil.com>
Closes: https://lore.kernel.org/lkml/354a2690-9bbf-4ccb-8769-fa94707a9340@molgen.mpg.de/
Cc: Breno Leitao <leitao@debian.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250223221708.27130-1-frederic@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Breno Leitao reported the splat below. [0]
Commit 65161fb544aa ("net: Fix dev_net(dev) race in
unregister_netdevice_notifier_dev_net().") added the
DEBUG_NET_WARN_ON_ONCE(), assuming that the netdev is not
registered before register_netdevice_notifier_dev_net().
But the assumption was simply wrong.
Let's use rtnl_net_dev_lock() in register_netdevice_notifier_dev_net().
[0]:
WARNING: CPU: 25 PID: 849 at net/core/dev.c:2150 register_netdevice_notifier_dev_net (net/core/dev.c:2150)
<TASK>
? __warn (kernel/panic.c:242 kernel/panic.c:748)
? register_netdevice_notifier_dev_net (net/core/dev.c:2150)
? register_netdevice_notifier_dev_net (net/core/dev.c:2150)
? report_bug (lib/bug.c:? lib/bug.c:219)
? handle_bug (arch/x86/kernel/traps.c:285)
? exc_invalid_op (arch/x86/kernel/traps.c:309)
? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)
? register_netdevice_notifier_dev_net (net/core/dev.c:2150)
? register_netdevice_notifier_dev_net (./include/net/net_namespace.h:406 ./include/linux/netdevice.h:2663 net/core/dev.c:2144)
mlx5e_mdev_notifier_event+0x9f/0xf0 mlx5_ib
notifier_call_chain.llvm.12241336988804114627 (kernel/notifier.c:85)
blocking_notifier_call_chain (kernel/notifier.c:380)
mlx5_core_uplink_netdev_event_replay (drivers/net/ethernet/mellanox/mlx5/core/main.c:352)
mlx5_ib_roce_init.llvm.12447516292400117075+0x1c6/0x550 mlx5_ib
mlx5r_probe+0x375/0x6a0 mlx5_ib
? kernfs_put (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-arch-fallback.h:2278 ./include/linux/atomic/atomic-instrumented.h:1384 fs/kernfs/dir.c:557)
? auxiliary_match_id (drivers/base/auxiliary.c:174)
? mlx5r_mp_remove+0x160/0x160 mlx5_ib
really_probe (drivers/base/dd.c:? drivers/base/dd.c:658)
driver_probe_device (drivers/base/dd.c:830)
__driver_attach (drivers/base/dd.c:1217)
bus_for_each_dev (drivers/base/bus.c:369)
? driver_attach (drivers/base/dd.c:1157)
bus_add_driver (drivers/base/bus.c:679)
driver_register (drivers/base/driver.c:249)
Fixes: 7fb1073300a2 ("net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().")
Reported-by: Breno Leitao <leitao@debian.org>
Closes: https://lore.kernel.org/netdev/20250224-noisy-cordial-roadrunner-fad40c@leitao/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250225211023.96448-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix a shadow variable warning in net/core/dev.c when compiled with
CONFIG_LOCKDEP enabled. The warning occurs because 'dev' is redeclared
inside the while loop, shadowing the outer scope declaration.
net/core/dev.c:11211:22: warning: declaration shadows a local variable [-Wshadow]
struct net_device *dev = list_first_entry(&unlink_list,
net/core/dev.c:11202:21: note: previous declaration is here
struct net_device *dev, *tmp;
Remove the redundant declaration since the variable is already defined
in the outer scope and will be overwritten in the subsequent
list_for_each_entry_safe() loop anyway.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250221-netcons_fix_shadow-v1-1-dee20c8658dd@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-02-20
We've added 19 non-merge commits during the last 8 day(s) which contain
a total of 35 files changed, 1126 insertions(+), 53 deletions(-).
The main changes are:
1) Add TCP_RTO_MAX_MS support to bpf_set/getsockopt, from Jason Xing
2) Add network TX timestamping support to BPF sock_ops, from Jason Xing
3) Add TX metadata Launch Time support, from Song Yoong Siang
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
igc: Add launch time support to XDP ZC
igc: Refactor empty frame insertion for launch time support
net: stmmac: Add launch time support to XDP ZC
selftests/bpf: Add launch time request to xdp_hw_metadata
xsk: Add launch time hardware offload support to XDP Tx metadata
selftests/bpf: Add simple bpf tests in the tx path for timestamping feature
bpf: Support selective sampling for bpf timestamping
bpf: Add BPF_SOCK_OPS_TSTAMP_SENDMSG_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_ACK_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SND_HW_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SND_SW_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback
net-timestamp: Prepare for isolating two modes of SO_TIMESTAMPING
bpf: Disable unsafe helpers in TX timestamping callbacks
bpf: Prevent unsafe access to the sock fields in the BPF timestamping callback
bpf: Prepare the sock_ops ctx and call bpf prog for TX timestamping
bpf: Add networking timestamping support to bpf_get/setsockopt()
selftests/bpf: Add rto max for bpf_setsockopt test
bpf: Support TCP_RTO_MAX_MS for bpf_setsockopt
====================
Link: https://patch.msgid.link/20250221022104.386462-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Support SCM_TSTAMP_SCHED case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SCHED_CB. This
callback will occur at the same timestamping point as the user
space's SCM_TSTAMP_SCHED. The BPF program can use it to get the
same SCM_TSTAMP_SCHED timestamp without modifying the user-space
application.
A new SKBTX_BPF flag is added to mark skb_shinfo(skb)->tx_flags,
ensuring that the new BPF timestamping and the current user
space's SO_TIMESTAMPING do not interfere with each other.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-7-kerneljasonxing@gmail.com
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Cross-merge networking fixes after downstream PR (net-6.14-rc4).
No conflicts or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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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 <edumazet@google.com>
Fixes: dbae2b062824 ("net: skb: introduce and use a single page frag cache")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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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 <edumazet@google.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-1-d3d6892db9e1@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The following sequence is basically illegal when dev was fetched
without lookup because dev_net(dev) might be different after holding
rtnl_net_lock():
net = dev_net(dev);
rtnl_net_lock(net);
Let's use rtnl_net_dev_lock() in unregister_netdev().
Note that there is no real bug in unregister_netdev() for now
because RTNL protects the scope even if dev_net(dev) is changed
before/after RTNL.
Fixes: 00fb9823939e ("dev: Hold per-netns RTNL in (un)?register_netdev().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250217191129.19967-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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After the cited commit, dev_net(dev) is fetched before holding RTNL
and passed to __unregister_netdevice_notifier_net().
However, dev_net(dev) might be different after holding RTNL.
In the reported case [0], while removing a VF device, its netns was
being dismantled and the VF was moved to init_net.
So the following sequence is basically illegal when dev was fetched
without lookup:
net = dev_net(dev);
rtnl_net_lock(net);
Let's use a new helper rtnl_net_dev_lock() to fix the race.
It fetches dev_net_rcu(dev), bumps its net->passive, and checks if
dev_net_rcu(dev) is changed after rtnl_net_lock().
[0]:
BUG: KASAN: slab-use-after-free in notifier_call_chain (kernel/notifier.c:75 (discriminator 2))
Read of size 8 at addr ffff88810cefb4c8 by task test-bridge-lag/21127
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:123)
print_report (mm/kasan/report.c:379 mm/kasan/report.c:489)
kasan_report (mm/kasan/report.c:604)
notifier_call_chain (kernel/notifier.c:75 (discriminator 2))
call_netdevice_notifiers_info (net/core/dev.c:2011)
unregister_netdevice_many_notify (net/core/dev.c:11551)
unregister_netdevice_queue (net/core/dev.c:11487)
unregister_netdev (net/core/dev.c:11635)
mlx5e_remove (drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6552 drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6579) mlx5_core
auxiliary_bus_remove (drivers/base/auxiliary.c:230)
device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296)
bus_remove_device (./include/linux/kobject.h:193 drivers/base/base.h:73 drivers/base/bus.c:583)
device_del (drivers/base/power/power.h:142 drivers/base/core.c:3855)
mlx5_rescan_drivers_locked (./include/linux/auxiliary_bus.h:241 drivers/net/ethernet/mellanox/mlx5/core/dev.c:333 drivers/net/ethernet/mellanox/mlx5/core/dev.c:535 drivers/net/ethernet/mellanox/mlx5/core/dev.c:549) mlx5_core
mlx5_unregister_device (drivers/net/ethernet/mellanox/mlx5/core/dev.c:468) mlx5_core
mlx5_uninit_one (./include/linux/instrumented.h:68 ./include/asm-generic/bitops/instrumented-non-atomic.h:141 drivers/net/ethernet/mellanox/mlx5/core/main.c:1563) mlx5_core
remove_one (drivers/net/ethernet/mellanox/mlx5/core/main.c:965 drivers/net/ethernet/mellanox/mlx5/core/main.c:2019) mlx5_core
pci_device_remove (./include/linux/pm_runtime.h:129 drivers/pci/pci-driver.c:475)
device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296)
unbind_store (drivers/base/bus.c:245)
kernfs_fop_write_iter (fs/kernfs/file.c:338)
vfs_write (fs/read_write.c:587 (discriminator 1) fs/read_write.c:679 (discriminator 1))
ksys_write (fs/read_write.c:732)
do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
RIP: 0033:0x7f6a4d5018b7
Fixes: 7fb1073300a2 ("net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().")
Reported-by: Yael Chemla <ychemla@nvidia.com>
Closes: https://lore.kernel.org/netdev/146eabfe-123c-4970-901e-e961b4c09bc3@nvidia.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250217191129.19967-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The old_flags variable is declared twice in __dev_change_flags(),
causing a shadow variable warning. This patch fixes the issue by
removing the redundant declaration, reusing the existing old_flags
variable instead.
net/core/dev.c:9225:16: warning: declaration shadows a local variable [-Wshadow]
9225 | unsigned int old_flags = dev->flags;
| ^
net/core/dev.c:9185:15: note: previous declaration is here
9185 | unsigned int old_flags = dev->flags;
| ^
1 warning generated.
Remove the redundant inner declaration and reuse the existing old_flags
variable since its value is not needed outside the if block, and it is
safe to reuse the variable. This eliminates the warning while
maintaining the same functionality.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250217-old_flags-v2-1-4cda3b43a35f@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.
Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.
Patch was created by using Coccinelle.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/861d9b287f2b5206b853dbcc0f302127f2a7f8ac.1738746872.git.namcao@linutronix.de
|
|
In commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present"),
napi_id_valid function was added. Use the helper to refactor open-coded
checks in the source.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Stefano Jordhani <sjordhani@gmail.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk> # for iouring
Link: https://patch.msgid.link/20250214181801.931-1-sjordhani@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
David Wei says:
====================
io_uring zero copy rx
This patchset contains net/ patches needed by a new io_uring request
implementing zero copy rx into userspace pages, eliminating a kernel
to user copy.
We configure a page pool that a driver uses to fill a hw rx queue to
hand out user pages instead of kernel pages. Any data that ends up
hitting this hw rx queue will thus be dma'd into userspace memory
directly, without needing to be bounced through kernel memory. 'Reading'
data out of a socket instead becomes a _notification_ mechanism, where
the kernel tells userspace where the data is. The overall approach is
similar to the devmem TCP proposal.
This relies on hw header/data split, flow steering and RSS to ensure
packet headers remain in kernel memory and only desired flows hit a hw
rx queue configured for zero copy. Configuring this is outside of the
scope of this patchset.
We share netdev core infra with devmem TCP. The main difference is that
io_uring is used for the uAPI and the lifetime of all objects are bound
to an io_uring instance. Data is 'read' using a new io_uring request
type. When done, data is returned via a new shared refill queue. A zero
copy page pool refills a hw rx queue from this refill queue directly. Of
course, the lifetime of these data buffers are managed by io_uring
rather than the networking stack, with different refcounting rules.
This patchset is the first step adding basic zero copy support. We will
extend this iteratively with new features e.g. dynamically allocated
zero copy areas, THP support, dmabuf support, improved copy fallback,
general optimisations and more.
In terms of netdev support, we're first targeting Broadcom bnxt. Patches
aren't included since Taehee Yoo has already sent a more comprehensive
patchset adding support in [1]. Google gve should already support this,
and Mellanox mlx5 support is WIP pending driver changes.
===========
Performance
===========
Note: Comparison with epoll + TCP_ZEROCOPY_RECEIVE isn't done yet.
Test setup:
* AMD EPYC 9454
* Broadcom BCM957508 200G
* Kernel v6.11 base [2]
* liburing fork [3]
* kperf fork [4]
* 4K MTU
* Single TCP flow
With application thread + net rx softirq pinned to _different_ cores:
+-------------------------------+
| epoll | io_uring |
|-----------|-------------------|
| 82.2 Gbps | 116.2 Gbps (+41%) |
+-------------------------------+
Pinned to _same_ core:
+-------------------------------+
| epoll | io_uring |
|-----------|-------------------|
| 62.6 Gbps | 80.9 Gbps (+29%) |
+-------------------------------+
=====
Links
=====
Broadcom bnxt support:
[1]: https://lore.kernel.org/20241003160620.1521626-8-ap420073@gmail.com
Linux kernel branch including io_uring bits:
[2]: https://github.com/isilence/linux.git zcrx/v13
liburing for testing:
[3]: https://github.com/isilence/liburing.git zcrx/next
kperf for testing:
[4]: https://git.kernel.dk/kperf.git
====================
Link: https://patch.msgid.link/20250204215622.695511-1-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Devmem TCP needs a hook in unregister_netdevice_many_notify() to upkeep
the set tracking queues it's bound to, i.e. ->bound_rxqs. Instead of
devmem sticking directly out of the genetic path, add a mp function.
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://patch.msgid.link/20250204215622.695511-8-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.14-rc2).
No conflicts or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Add READ_ONCE() around reads of skb->dev->reg_state, because
this field can be changed from other threads/cpus.
Instead of calling dev_kfree_skb_irq() and kfree_skb()
while interrupts are masked and locks held,
use a temporary list and use __skb_queue_purge_reason()
Use SKB_DROP_REASON_DEV_READY drop reason to better
describe why these skbs are dropped.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20250204144825.316785-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Drivers should always disable a NAPI instance before removing it.
If they don't the instance may be queued for polling.
Since commit 86e25f40aa1e ("net: napi: Add napi_config")
we also remove the NAPI from the busy polling hash table
in napi_disable(), so not disabling would leave a stale
entry there.
Use of busy polling is relatively uncommon so bugs may be lurking
in the drivers. Add an explicit warning.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250203215816.1294081-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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 <pabeni@redhat.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/2e1c444cf0f63ae472baff29862c4c869be17031.1738432804.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This patch reverts following changes:
83419b61d187 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)
ae646f1a0bb9 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)
cfa579f66656 net: no longer hold RTNL while calling flush_all_backlogs()
This caused issues in layers holding a private mutex:
cleanup_net()
rtnl_lock();
mutex_lock(subsystem_mutex);
unregister_netdevice();
rtnl_unlock(); // LOCKDEP violation
rtnl_lock();
I will revisit this in next cycle, opt-in for the new behavior
from safe contexts only.
Fixes: cfa579f66656 ("net: no longer hold RTNL while calling flush_all_backlogs()")
Fixes: ae646f1a0bb9 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)")
Fixes: 83419b61d187 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)")
Reported-by: syzbot+5b9196ecf74447172a9a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6789d55f.050a0220.20d369.004e.GAE@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250129142726.747726-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Device-bound programs are used to support RX metadata kfuncs. These
kfuncs are driver-specific and rely on the driver context to read the
metadata. This means they can't work in generic XDP mode. However, there
is no check to disallow such programs from being attached in generic
mode, in which case the metadata kfuncs will be called in an invalid
context, leading to crashes.
Fix this by adding a check to disallow attaching device-bound programs
in generic mode.
Fixes: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs")
Reported-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Closes: https://lore.kernel.org/r/dae862ec-43b5-41a0-8edf-46c59071cdda@hetzner-cloud.de
Tested-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250127131344.238147-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Page ppol tried to cache the NAPI ID in page pool info to avoid
having a dependency on the life cycle of the NAPI instance.
Since commit under Fixes the NAPI ID is not populated until
napi_enable() and there's a good chance that page pool is
created before NAPI gets enabled.
Protect the NAPI pointer with the existing page pool mutex,
the reading path already holds it. napi_id itself we need
to READ_ONCE(), it's protected by netdev_lock() which are
not holding in page pool.
Before this patch napi IDs were missing for mlx5:
# ./cli.py --spec netlink/specs/netdev.yaml --dump page-pool-get
[{'id': 144, 'ifindex': 2, 'inflight': 3072, 'inflight-mem': 12582912},
{'id': 143, 'ifindex': 2, 'inflight': 5568, 'inflight-mem': 22806528},
{'id': 142, 'ifindex': 2, 'inflight': 5120, 'inflight-mem': 20971520},
{'id': 141, 'ifindex': 2, 'inflight': 4992, 'inflight-mem': 20447232},
...
After:
[{'id': 144, 'ifindex': 2, 'inflight': 3072, 'inflight-mem': 12582912,
'napi-id': 565},
{'id': 143, 'ifindex': 2, 'inflight': 4224, 'inflight-mem': 17301504,
'napi-id': 525},
{'id': 142, 'ifindex': 2, 'inflight': 4288, 'inflight-mem': 17563648,
'napi-id': 524},
...
Fixes: 86e25f40aa1e ("net: napi: Add napi_config")
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250123231620.1086401-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
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 <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250119020518.1962249-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
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 <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250119020518.1962249-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This patch addresses issues with filter counting in block (tcf_block),
particularly for software bypass scenarios, by introducing a more
accurate mechanism using useswcnt.
Previously, filtercnt and skipswcnt were introduced by:
Commit 2081fd3445fe ("net: sched: cls_api: add filter counter") and
Commit f631ef39d819 ("net: sched: cls_api: add skip_sw counter")
filtercnt tracked all tp (tcf_proto) objects added to a block, and
skipswcnt counted tp objects with the skipsw attribute set.
The problem is: a single tp can contain multiple filters, some with skipsw
and others without. The current implementation fails in the case:
When the first filter in a tp has skipsw, both skipswcnt and filtercnt
are incremented, then adding a second filter without skipsw to the same
tp does not modify these counters because tp->counted is already set.
This results in bypass software behavior based solely on skipswcnt
equaling filtercnt, even when the block includes filters without
skipsw. Consequently, filters without skipsw are inadvertently bypassed.
To address this, the patch introduces useswcnt in block to explicitly count
tp objects containing at least one filter without skipsw. Key changes
include:
Whenever a filter without skipsw is added, its tp is marked with usesw
and counted in useswcnt. tc_run() now uses useswcnt to determine software
bypass, eliminating reliance on filtercnt and skipswcnt.
This refined approach prevents software bypass for blocks containing
mixed filters, ensuring correct behavior in tc_run().
Additionally, as atomic operations on useswcnt ensure thread safety and
tp->lock guards access to tp->usesw and tp->counted, the broader lock
down_write(&block->cb_lock) is no longer required in tc_new_tfilter(),
and this resolves a performance regression caused by the filter counting
mechanism during parallel filter insertions.
The improvement can be demonstrated using the following script:
# cat insert_tc_rules.sh
tc qdisc add dev ens1f0np0 ingress
for i in $(seq 16); do
taskset -c $i tc -b rules_$i.txt &
done
wait
Each of rules_$i.txt files above includes 100000 tc filter rules to a
mlx5 driver NIC ens1f0np0.
Without this patch:
# time sh insert_tc_rules.sh
real 0m50.780s
user 0m23.556s
sys 4m13.032s
With this patch:
# time sh insert_tc_rules.sh
real 0m17.718s
user 0m7.807s
sys 3m45.050s
Fixes: 047f340b36fc ("net: sched: make skip_sw actually skip software")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
After 1b23cdbd2bbc ("net: protect netdev->napi_list with netdev_lock()")
it makes sense to iterate through dev->napi_list while holding
the device lock.
Also call synchronize_net() at most one time.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250117232113.1612899-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzbot complained that free_netdev() was calling netif_napi_del()
after dev->lock mutex has been destroyed.
This fires a warning for CONFIG_DEBUG_MUTEXES=y builds.
Move mutex_destroy(&dev->lock) near the end of free_netdev().
[1]
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 5971 at kernel/locking/mutex.c:564 __mutex_lock_common kernel/locking/mutex.c:564 [inline]
WARNING: CPU: 0 PID: 5971 at kernel/locking/mutex.c:564 __mutex_lock+0xdac/0xee0 kernel/locking/mutex.c:735
Modules linked in:
CPU: 0 UID: 0 PID: 5971 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-01131-g8d20dcda404d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:564 [inline]
RIP: 0010:__mutex_lock+0xdac/0xee0 kernel/locking/mutex.c:735
Code: 0f b6 04 38 84 c0 0f 85 1a 01 00 00 83 3d 6f 40 4c 04 00 75 19 90 48 c7 c7 60 84 0a 8c 48 c7 c6 00 85 0a 8c e8 f5 dc 91 f5 90 <0f> 0b 90 90 90 e9 c7 f3 ff ff 90 0f 0b 90 e9 29 f8 ff ff 90 0f 0b
RSP: 0018:ffffc90003317580 EFLAGS: 00010246
RAX: ee0f97edaf7b7d00 RBX: ffff8880299f8cb0 RCX: ffff8880323c9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003317710 R08: ffffffff81602ac2 R09: 1ffff110170c519a
R10: dffffc0000000000 R11: ffffed10170c519b R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000662ec4 R15: dffffc0000000000
FS: 000055557a046500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd581d46ff8 CR3: 000000006f870000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
netdev_lock include/linux/netdevice.h:2691 [inline]
__netif_napi_del include/linux/netdevice.h:2829 [inline]
netif_napi_del include/linux/netdevice.h:2848 [inline]
free_netdev+0x2d9/0x610 net/core/dev.c:11621
netdev_run_todo+0xf21/0x10d0 net/core/dev.c:11189
nsim_destroy+0x3c3/0x620 drivers/net/netdevsim/netdev.c:1028
__nsim_dev_port_del+0x14b/0x1b0 drivers/net/netdevsim/dev.c:1428
nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline]
nsim_dev_reload_destroy+0x28a/0x490 drivers/net/netdevsim/dev.c:1661
nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1676
device_remove drivers/base/dd.c:567 [inline]
Fixes: 1b23cdbd2bbc ("net: protect netdev->napi_list with netdev_lock()")
Reported-by: syzbot+85ff1051228a04613a32@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/678add43.050a0220.303755.0016.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250117224626.1427577-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Basically, dev_ifsioc() operates on the passed single netns (except
for netdev notifier chains with lower/upper devices for which we will
need more changes).
Let's hold rtnl_net_lock() for dev_ifsioc().
Now that NETDEV_CHANGENAME is always triggered under rtnl_net_lock()
of the device's netns. (do_setlink() and dev_ifsioc())
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
devnet_rename_sem is no longer used since commit
0840556e5a3a ("net: Protect dev->name by seqlock.").
Also, RTNL serialises dev_change_name().
Let's remove devnet_rename_sem.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The cited commit forgot to add netdev_rename_lock in one of the
error paths in dev_change_name().
Let's hold netdev_rename_lock before restoring the old dev->name.
Fixes: 0840556e5a3a ("net: Protect dev->name by seqlock.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Eric Dumazet says:
====================
net: reduce RTNL pressure in unregister_netdevice()
One major source of RTNL contention resides in unregister_netdevice()
Due to RCU protection of various network structures, and
unregister_netdevice() being a synchronous function,
it is calling potentially slow functions while holding RTNL.
I think we can release RTNL in two points, so that three
slow functions are called while RTNL can be used
by other threads.
v1: https://lore.kernel.org/netdev/20250107130906.098fc8d6@kernel.org/T/#m398c95f5778e1ff70938e079d3c4c43c050ad2a6
====================
Link: https://patch.msgid.link/20250114205531.967841-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
One synchronize_net() call is currently done while holding RTNL.
This is source of RTNL contention in workloads adding and deleting
many network namespaces per second, because synchronize_rcu()
and synchronize_rcu_expedited() can use 60+ ms in some cases.
For cleanup_net() use, temporarily release RTNL
while calling the last synchronize_net().
This should be safe, because devices are no longer visible
to other threads after unlist_netdevice() call
and setting dev->reg_state to NETREG_UNREGISTERING.
In any case, the new netdev_lock() / netdev_unlock()
infrastructure that we are adding should allow
to fix potential issues, with a combination
of a per-device mutex and dev->reg_state awareness.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250114205531.967841-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Two synchronize_net() calls are currently done while holding RTNL.
This is source of RTNL contention in workloads adding and deleting
many network namespaces per second, because synchronize_rcu()
and synchronize_rcu_expedited() can use 60+ ms in some cases.
For cleanup_net() use, temporarily release RTNL
while calling the last synchronize_net().
This should be safe, because devices are no longer visible
to other threads at this point.
In any case, the new netdev_lock() / netdev_unlock()
infrastructure that we are adding should allow
to fix potential issues, with a combination
of a per-device mutex and dev->reg_state awareness.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250114205531.967841-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
flush_all_backlogs() is called from unregister_netdevice_many_notify()
as part of netdevice dismantles.
This is currently called under RTNL, and can last up to 50 ms
on busy hosts.
There is no reason to hold RTNL at this stage, if our caller
is cleanup_net() : netns are no more visible, devices
are in NETREG_UNREGISTERING state and no other thread
could mess our state while RTNL is temporarily released.
In order to provide isolation, this patch provides a separate
'net_todo_list' for cleanup_net().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250114205531.967841-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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flush_all_backlogs() uses per-cpu and static data to hold its
temporary data, on the assumption it is called under RTNL
protection.
Following patch in the series will break this assumption.
Use instead a dynamically allocated piece of memory.
In the unlikely case the allocation fails,
use a boot-time allocated memory.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250114205531.967841-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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cleanup_net() is the single thread responsible
for netns dismantles, and a serious bottleneck.
Before we can get per-netns RTNL, make sure
all synchronize_net() called from this thread
are using rcu_synchronize_expedited().
v3: deal with CONFIG_NET_NS=n
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250114205531.967841-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Take netdev_lock() in netif_napi_set_irq(). All NAPI "control fields"
are now protected by that lock (most of the other ones are set during
napi add/del). The napi_hash_node is fully protected by the hash
spin lock, but close enough for the kdoc...
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Now that NAPI instances can't come and go without holding
netdev->lock we can trivially switch from rtnl_lock() to
netdev_lock() for setting netdev->threaded via sysfs.
Note that since we do not lock netdev_lock around sysfs
calls in the core we don't have to "trylock" like we do
with rtnl_lock.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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In prep for dropping rtnl_lock, start locking netdev->lock in netlink
genl ops. We need to be using netdev->up instead of flags & IFF_UP.
We can remove the RCU lock protection for the NAPI since NAPI list
is protected by netdev->lock already.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Wrap napi_enable() / napi_disable() with netdev_lock().
Provide the "already locked" flavor of the API.
iavf needs the usual adjustment. A number of drivers call
napi_enable() under a spin lock, so they have to be modified
to take netdev_lock() first, then spin lock then call
napi_enable_locked().
Protecting napi_enable() implies that napi->napi_id is protected
by netdev_lock().
Acked-by: Francois Romieu <romieu@fr.zoreil.com> # via-velocity
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Hold netdev->lock when NAPIs are getting added or removed.
This will allow safe access to NAPI instances of a net_device
without rtnl_lock.
Create a family of helpers which assume the lock is already taken.
Switch iavf to them, as it makes extensive use of netdev->lock,
already.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Some uAPI (netdev netlink) hide net_device's sub-objects while
the interface is down to ensure uniform behavior across drivers.
To remove the rtnl_lock dependency from those uAPIs we need a way
to safely tell if the device is down or up.
Add an indication of whether device is open or closed, protected
by netdev->lock. The semantics are the same as IFF_UP, but taking
netdev_lock around every write to ->flags would be a lot of code
churn.
We don't want to blanket the entire open / close path by netdev_lock,
because it will prevent us from applying it to specific structures -
core helpers won't be able to take that lock from any function
called by the drivers on open/close paths.
So the state of the flag is "pessimistic", as in it may report false
negatives, but never false positives.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Stanislav Fomichev
Dan Carpenter
Nicolas Dichtel
Jakub Kicinski
Alexander Lobakin
Ahmed Zaki
Frederic Weisbecker
Kuniyuki Iwashima
Breno Leitao
Jason Xing
Paolo Abeni
Nam Cao
Stefano Jordhani
Pavel Begunkov
Eric Dumazet
Toke Høiland-Jørgensen
Xin Long