While reading netdev_unregister_timeout_secs, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: 5aa3afe107 ("net: make unregister netdev warning timeout configurable")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_budget_usecs, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 7acf8a1e8a ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_budget, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 51b0bdedb8 ("[NET]: Separate two usages of netdev_max_backlog.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_tstamp_prequeue, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 3b098e2d7c ("net: Consistent skb timestamping")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_max_backlog, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
While at it, we remove the unnecessary spaces in the doc.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading weight_p, it can be changed concurrently. Thus, we need
to add READ_ONCE() to its reader.
Also, dev_[rt]x_weight can be read/written at the same time. So, we
need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to
use the same weight_p while changing dev_[rt]x_weight, we add a mutex
in proc_do_dev_weight().
Fixes: 3d48b53fb2 ("net: dev_weight: TX/RX orthogonality")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
bpf-next 2022-07-22
We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).
The main changes are:
1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.
2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
syscalls through kprobe mechanism, from Andrii Nakryiko.
3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
function, from Song Liu & Jiri Olsa.
4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.
5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
with kernel symbols, from Alan Maguire.
6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.
7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.
8) libbpf support for writing custom perf event readers, from Jon Doron.
9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.
10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.
11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.
12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.
13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.
14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.
15) Make non-prealloced BPF map allocations low priority to play better with
memcg limits, from Yafang Shao.
16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.
17) Various smaller cleanups and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
bpf: Simplify bpf_prog_pack_[size|mask]
bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
bpf, x64: Allow to use caller address from stack
ftrace: Allow IPMODIFY and DIRECT ops on the same function
ftrace: Add modify_ftrace_direct_multi_nolock
bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
selftests/bpf: Fix test_verifier failed test in unprivileged mode
selftests/bpf: Add negative tests for new nf_conntrack kfuncs
selftests/bpf: Add tests for new nf_conntrack kfuncs
selftests/bpf: Add verifier tests for trusted kfunc args
net: netfilter: Add kfuncs to set and change CT status
net: netfilter: Add kfuncs to set and change CT timeout
net: netfilter: Add kfuncs to allocate and insert CT
net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
bpf: Add documentation for kfuncs
bpf: Add support for forcing kfunc args to be trusted
bpf: Switch to new kfunc flags infrastructure
tools/resolve_btfids: Add support for 8-byte BTF sets
bpf: Introduce 8-byte BTF set
...
====================
Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The byte queue limits (BQL) mechanism is intended to move queuing from
the driver to the network stack in order to reduce latency caused by
excessive queuing in hardware. However, when transmitting or redirecting
a packet using generic XDP, the qdisc layer is bypassed and there are no
additional queues. Since netif_xmit_stopped() also takes BQL limits into
account, but without having any alternative queuing, packets are
silently dropped.
This patch modifies the drop condition to only consider cases when the
driver itself cannot accept any more packets. This is analogous to the
condition in __dev_direct_xmit(). Dropped packets are also counted on
the device.
Bypassing the qdisc layer in the generic XDP TX path means that XDP
packets are able to starve other packets going through a qdisc, and
DDOS attacks will be more effective. In-driver-XDP use dedicated TX
queues, so they do not have this starvation issue.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220705082345.2494312-1-johan.almbladh@anyfinetworks.com
This is a follow up of commit 3226b158e6
("net: avoid 32 x truesize under-estimation for tiny skbs")
When/if we increase MAX_SKB_FRAGS, we better make sure
the old bug will not come back.
Adding a check in napi_get_frags() would be costly,
even if using DEBUG_NET_WARN_ON_ONCE().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
One check in dev_loopback_xmit() has not caught issues
in the past.
Keep it for CONFIG_DEBUG_NET=y builds only.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As explained in commit 316580b69d ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Core
----
- Support TCPv6 segmentation offload with super-segments larger than
64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).
- Generalize skb freeing deferral to per-cpu lists, instead of
per-socket lists.
- Add a netdev statistic for packets dropped due to L2 address
mismatch (rx_otherhost_dropped).
- Continue work annotating skb drop reasons.
- Accept alternative netdev names (ALT_IFNAME) in more netlink
requests.
- Add VLAN support for AF_PACKET SOCK_RAW GSO.
- Allow receiving skb mark from the socket as a cmsg.
- Enable memcg accounting for veth queues, sysctl tables and IPv6.
BPF
---
- Add libbpf support for User Statically-Defined Tracing (USDTs).
- Speed up symbol resolution for kprobes multi-link attachments.
- Support storing typed pointers to referenced and unreferenced
objects in BPF maps.
- Add support for BPF link iterator.
- Introduce access to remote CPU map elements in BPF per-cpu map.
- Allow middle-of-the-road settings for the
kernel.unprivileged_bpf_disabled sysctl.
- Implement basic types of dynamic pointers e.g. to allow for
dynamically sized ringbuf reservations without extra memory copies.
Protocols
---------
- Retire port only listening_hash table, add a second bind table
hashed by port and address. Avoid linear list walk when binding
to very popular ports (e.g. 443).
- Add bridge FDB bulk flush filtering support allowing user space
to remove all FDB entries matching a condition.
- Introduce accept_unsolicited_na sysctl for IPv6 to implement
router-side changes for RFC9131.
- Support for MPTCP path manager in user space.
- Add MPTCP support for fallback to regular TCP for connections
that have never connected additional subflows or transmitted
out-of-sequence data (partial support for RFC8684 fallback).
- Avoid races in MPTCP-level window tracking, stabilize and improve
throughput.
- Support lockless operation of GRE tunnels with seq numbers enabled.
- WiFi support for host based BSS color collision detection.
- Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.
- Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).
- Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).
- Allow matching on the number of VLAN tags via tc-flower.
- Add tracepoint for tcp_set_ca_state().
Driver API
----------
- Improve error reporting from classifier and action offload.
- Add support for listing line cards in switches (devlink).
- Add helpers for reporting page pool statistics with ethtool -S.
- Add support for reading clock cycles when using PTP virtual clocks,
instead of having the driver convert to time before reporting.
This makes it possible to report time from different vclocks.
- Support configuring low-latency Tx descriptor push via ethtool.
- Separate Clause 22 and Clause 45 MDIO accesses more explicitly.
New hardware / drivers
----------------------
- Ethernet:
- Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
- Sunplus SP7021 SoC (sp7021_emac)
- Add support for Renesas RZ/V2M (in ravb)
- Add support for MediaTek mt7986 switches (in mtk_eth_soc)
- Ethernet PHYs:
- ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
- TI DP83TD510 PHY
- Microchip LAN8742/LAN88xx PHYs
- WiFi:
- Driver for pureLiFi X, XL, XC devices (plfxlc)
- Driver for Silicon Labs devices (wfx)
- Support for WCN6750 (in ath11k)
- Support Realtek 8852ce devices (in rtw89)
- Mobile:
- MediaTek T700 modems (Intel 5G 5000 M.2 cards)
- CAN:
- ctucanfd: add support for CTU CAN FD open-source IP core
from Czech Technical University in Prague
Drivers
-------
- Delete a number of old drivers still using virt_to_bus().
- Ethernet NICs:
- intel: support TSO on tunnels MPLS
- broadcom: support multi-buffer XDP
- nfp: support VF rate limiting
- sfc: use hardware tx timestamps for more than PTP
- mlx5: multi-port eswitch support
- hyper-v: add support for XDP_REDIRECT
- atlantic: XDP support (including multi-buffer)
- macb: improve real-time perf by deferring Tx processing to NAPI
- High-speed Ethernet switches:
- mlxsw: implement basic line card information querying
- prestera: add support for traffic policing on ingress and egress
- Embedded Ethernet switches:
- lan966x: add support for packet DMA (FDMA)
- lan966x: add support for PTP programmable pins
- ti: cpsw_new: enable bc/mc storm prevention
- Qualcomm 802.11ax WiFi (ath11k):
- Wake-on-WLAN support for QCA6390 and WCN6855
- device recovery (firmware restart) support
- support setting Specific Absorption Rate (SAR) for WCN6855
- read country code from SMBIOS for WCN6855/QCA6390
- enable keep-alive during WoWLAN suspend
- implement remain-on-channel support
- MediaTek WiFi (mt76):
- support Wireless Ethernet Dispatch offloading packet movement
between the Ethernet switch and WiFi interfaces
- non-standard VHT MCS10-11 support
- mt7921 AP mode support
- mt7921 IPv6 NS offload support
- Ethernet PHYs:
- micrel: ksz9031/ksz9131: cabletest support
- lan87xx: SQI support for T1 PHYs
- lan937x: add interrupt support for link detection
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core
----
- Support TCPv6 segmentation offload with super-segments larger than
64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).
- Generalize skb freeing deferral to per-cpu lists, instead of
per-socket lists.
- Add a netdev statistic for packets dropped due to L2 address
mismatch (rx_otherhost_dropped).
- Continue work annotating skb drop reasons.
- Accept alternative netdev names (ALT_IFNAME) in more netlink
requests.
- Add VLAN support for AF_PACKET SOCK_RAW GSO.
- Allow receiving skb mark from the socket as a cmsg.
- Enable memcg accounting for veth queues, sysctl tables and IPv6.
BPF
---
- Add libbpf support for User Statically-Defined Tracing (USDTs).
- Speed up symbol resolution for kprobes multi-link attachments.
- Support storing typed pointers to referenced and unreferenced
objects in BPF maps.
- Add support for BPF link iterator.
- Introduce access to remote CPU map elements in BPF per-cpu map.
- Allow middle-of-the-road settings for the
kernel.unprivileged_bpf_disabled sysctl.
- Implement basic types of dynamic pointers e.g. to allow for
dynamically sized ringbuf reservations without extra memory copies.
Protocols
---------
- Retire port only listening_hash table, add a second bind table
hashed by port and address. Avoid linear list walk when binding to
very popular ports (e.g. 443).
- Add bridge FDB bulk flush filtering support allowing user space to
remove all FDB entries matching a condition.
- Introduce accept_unsolicited_na sysctl for IPv6 to implement
router-side changes for RFC9131.
- Support for MPTCP path manager in user space.
- Add MPTCP support for fallback to regular TCP for connections that
have never connected additional subflows or transmitted
out-of-sequence data (partial support for RFC8684 fallback).
- Avoid races in MPTCP-level window tracking, stabilize and improve
throughput.
- Support lockless operation of GRE tunnels with seq numbers enabled.
- WiFi support for host based BSS color collision detection.
- Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.
- Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).
- Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).
- Allow matching on the number of VLAN tags via tc-flower.
- Add tracepoint for tcp_set_ca_state().
Driver API
----------
- Improve error reporting from classifier and action offload.
- Add support for listing line cards in switches (devlink).
- Add helpers for reporting page pool statistics with ethtool -S.
- Add support for reading clock cycles when using PTP virtual clocks,
instead of having the driver convert to time before reporting. This
makes it possible to report time from different vclocks.
- Support configuring low-latency Tx descriptor push via ethtool.
- Separate Clause 22 and Clause 45 MDIO accesses more explicitly.
New hardware / drivers
----------------------
- Ethernet:
- Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
- Sunplus SP7021 SoC (sp7021_emac)
- Add support for Renesas RZ/V2M (in ravb)
- Add support for MediaTek mt7986 switches (in mtk_eth_soc)
- Ethernet PHYs:
- ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
- TI DP83TD510 PHY
- Microchip LAN8742/LAN88xx PHYs
- WiFi:
- Driver for pureLiFi X, XL, XC devices (plfxlc)
- Driver for Silicon Labs devices (wfx)
- Support for WCN6750 (in ath11k)
- Support Realtek 8852ce devices (in rtw89)
- Mobile:
- MediaTek T700 modems (Intel 5G 5000 M.2 cards)
- CAN:
- ctucanfd: add support for CTU CAN FD open-source IP core from
Czech Technical University in Prague
Drivers
-------
- Delete a number of old drivers still using virt_to_bus().
- Ethernet NICs:
- intel: support TSO on tunnels MPLS
- broadcom: support multi-buffer XDP
- nfp: support VF rate limiting
- sfc: use hardware tx timestamps for more than PTP
- mlx5: multi-port eswitch support
- hyper-v: add support for XDP_REDIRECT
- atlantic: XDP support (including multi-buffer)
- macb: improve real-time perf by deferring Tx processing to NAPI
- High-speed Ethernet switches:
- mlxsw: implement basic line card information querying
- prestera: add support for traffic policing on ingress and egress
- Embedded Ethernet switches:
- lan966x: add support for packet DMA (FDMA)
- lan966x: add support for PTP programmable pins
- ti: cpsw_new: enable bc/mc storm prevention
- Qualcomm 802.11ax WiFi (ath11k):
- Wake-on-WLAN support for QCA6390 and WCN6855
- device recovery (firmware restart) support
- support setting Specific Absorption Rate (SAR) for WCN6855
- read country code from SMBIOS for WCN6855/QCA6390
- enable keep-alive during WoWLAN suspend
- implement remain-on-channel support
- MediaTek WiFi (mt76):
- support Wireless Ethernet Dispatch offloading packet movement
between the Ethernet switch and WiFi interfaces
- non-standard VHT MCS10-11 support
- mt7921 AP mode support
- mt7921 IPv6 NS offload support
- Ethernet PHYs:
- micrel: ksz9031/ksz9131: cabletest support
- lan87xx: SQI support for T1 PHYs
- lan937x: add interrupt support for link detection"
* tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1809 commits)
ptp: ocp: Add firmware header checks
ptp: ocp: fix PPS source selector debugfs reporting
ptp: ocp: add .init function for sma_op vector
ptp: ocp: vectorize the sma accessor functions
ptp: ocp: constify selectors
ptp: ocp: parameterize input/output sma selectors
ptp: ocp: revise firmware display
ptp: ocp: add Celestica timecard PCI ids
ptp: ocp: Remove #ifdefs around PCI IDs
ptp: ocp: 32-bit fixups for pci start address
Revert "net/smc: fix listen processing for SMC-Rv2"
ath6kl: Use cc-disable-warning to disable -Wdangling-pointer
selftests/bpf: Dynptr tests
bpf: Add dynptr data slices
bpf: Add bpf_dynptr_read and bpf_dynptr_write
bpf: Dynptr support for ring buffers
bpf: Add bpf_dynptr_from_mem for local dynptrs
bpf: Add verifier support for dynptrs
bpf: Suppress 'passing zero to PTR_ERR' warning
bpf: Introduce bpf_arch_text_invalidate for bpf_prog_pack
...
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Merge tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
"These updates continue to refine the work began in 5.17 and 5.18 of
modernizing the RNG's crypto and streamlining and documenting its
code.
New for 5.19, the updates aim to improve entropy collection methods
and make some initial decisions regarding the "premature next" problem
and our threat model. The cloc utility now reports that random.c is
931 lines of code and 466 lines of comments, not that basic metrics
like that mean all that much, but at the very least it tells you that
this is very much a manageable driver now.
Here's a summary of the various updates:
- The random_get_entropy() function now always returns something at
least minimally useful. This is the primary entropy source in most
collectors, which in the best case expands to something like RDTSC,
but prior to this change, in the worst case it would just return 0,
contributing nothing. For 5.19, additional architectures are wired
up, and architectures that are entirely missing a cycle counter now
have a generic fallback path, which uses the highest resolution
clock available from the timekeeping subsystem.
Some of those clocks can actually be quite good, despite the CPU
not having a cycle counter of its own, and going off-core for a
stamp is generally thought to increase jitter, something positive
from the perspective of entropy gathering. Done very early on in
the development cycle, this has been sitting in next getting some
testing for a while now and has relevant acks from the archs, so it
should be pretty well tested and fine, but is nonetheless the thing
I'll be keeping my eye on most closely.
- Of particular note with the random_get_entropy() improvements is
MIPS, which, on CPUs that lack the c0 count register, will now
combine the high-speed but short-cycle c0 random register with the
lower-speed but long-cycle generic fallback path.
- With random_get_entropy() now always returning something useful,
the interrupt handler now collects entropy in a consistent
construction.
- Rather than comparing two samples of random_get_entropy() for the
jitter dance, the algorithm now tests many samples, and uses the
amount of differing ones to determine whether or not jitter entropy
is usable and how laborious it must be. The problem with comparing
only two samples was that if the cycle counter was extremely slow,
but just so happened to be on the cusp of a change, the slowness
wouldn't be detected. Taking many samples fixes that to some
degree.
This, combined with the other improvements to random_get_entropy(),
should make future unification of /dev/random and /dev/urandom
maybe more possible. At the very least, were we to attempt it again
today (we're not), it wouldn't break any of Guenter's test rigs
that broke when we tried it with 5.18. So, not today, but perhaps
down the road, that's something we can revisit.
- We attempt to reseed the RNG immediately upon waking up from system
suspend or hibernation, making use of the various timestamps about
suspend time and such available, as well as the usual inputs such
as RDRAND when available.
- Batched randomness now falls back to ordinary randomness before the
RNG is initialized. This provides more consistent guarantees to the
types of random numbers being returned by the various accessors.
- The "pre-init injection" code is now gone for good. I suspect you
in particular will be happy to read that, as I recall you
expressing your distaste for it a few months ago. Instead, to avoid
a "premature first" issue, while still allowing for maximal amount
of entropy availability during system boot, the first 128 bits of
estimated entropy are used immediately as it arrives, with the next
128 bits being buffered. And, as before, after the RNG has been
fully initialized, it winds up reseeding anyway a few seconds later
in most cases. This resulted in a pretty big simplification of the
initialization code and let us remove various ad-hoc mechanisms
like the ugly crng_pre_init_inject().
- The RNG no longer pretends to handle the "premature next" security
model, something that various academics and other RNG designs have
tried to care about in the past. After an interesting mailing list
thread, these issues are thought to be a) mainly academic and not
practical at all, and b) actively harming the real security of the
RNG by delaying new entropy additions after a potential compromise,
making a potentially bad situation even worse. As well, in the
first place, our RNG never even properly handled the premature next
issue, so removing an incomplete solution to a fake problem was
particularly nice.
This allowed for numerous other simplifications in the code, which
is a lot cleaner as a consequence. If you didn't see it before,
https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/ may be a
thread worth skimming through.
- While the interrupt handler received a separate code path years ago
that avoids locks by using per-cpu data structures and a faster
mixing algorithm, in order to reduce interrupt latency, input and
disk events that are triggered in hardirq handlers were still
hitting locks and more expensive algorithms. Those are now
redirected to use the faster per-cpu data structures.
- Rather than having the fake-crypto almost-siphash-based random32
implementation be used right and left, and in many places where
cryptographically secure randomness is desirable, the batched
entropy code is now fast enough to replace that.
- As usual, numerous code quality and documentation cleanups. For
example, the initialization state machine now uses enum symbolic
constants instead of just hard coding numbers everywhere.
- Since the RNG initializes once, and then is always initialized
thereafter, a pretty heavy amount of code used during that
initialization is never used again. It is now completely cordoned
off using static branches and it winds up in the .text.unlikely
section so that it doesn't reduce cache compactness after the RNG
is ready.
- A variety of functions meant for waiting on the RNG to be
initialized were only used by vsprintf, and in not a particularly
optimal way. Replacing that usage with a more ordinary setup made
it possible to remove those functions.
- A cleanup of how we warn userspace about the use of uninitialized
/dev/urandom and uninitialized get_random_bytes() usage.
Interestingly, with the change you merged for 5.18 that attempts to
use jitter (but does not block if it can't), the majority of users
should never see those warnings for /dev/urandom at all now, and
the one for in-kernel usage is mainly a debug thing.
- The file_operations struct for /dev/[u]random now implements
.read_iter and .write_iter instead of .read and .write, allowing it
to also implement .splice_read and .splice_write, which makes
splice(2) work again after it was broken here (and in many other
places in the tree) during the set_fs() removal. This was a bit of
a last minute arrival from Jens that hasn't had as much time to
bake, so I'll be keeping my eye on this as well, but it seems
fairly ordinary. Unfortunately, read_iter() is around 3% slower
than read() in my tests, which I'm not thrilled about. But Jens and
Al, spurred by this observation, seem to be making progress in
removing the bottlenecks on the iter paths in the VFS layer in
general, which should remove the performance gap for all drivers.
- Assorted other bug fixes, cleanups, and optimizations.
- A small SipHash cleanup"
* tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (49 commits)
random: check for signals after page of pool writes
random: wire up fops->splice_{read,write}_iter()
random: convert to using fops->write_iter()
random: convert to using fops->read_iter()
random: unify batched entropy implementations
random: move randomize_page() into mm where it belongs
random: remove mostly unused async readiness notifier
random: remove get_random_bytes_arch() and add rng_has_arch_random()
random: move initialization functions out of hot pages
random: make consistent use of buf and len
random: use proper return types on get_random_{int,long}_wait()
random: remove extern from functions in header
random: use static branch for crng_ready()
random: credit architectural init the exact amount
random: handle latent entropy and command line from random_init()
random: use proper jiffies comparison macro
random: remove ratelimiting for in-kernel unseeded randomness
random: move initialization out of reseeding hot path
random: avoid initializing twice in credit race
random: use symbolic constants for crng_init states
...
random32.c has two random number generators in it: one that is meant to
be used deterministically, with some predefined seed, and one that does
the same exact thing as random.c, except does it poorly. The first one
has some use cases. The second one no longer does and can be replaced
with calls to random.c's proper random number generator.
The relatively recent siphash-based bad random32.c code was added in
response to concerns that the prior random32.c was too deterministic.
Out of fears that random.c was (at the time) too slow, this code was
anonymously contributed. Then out of that emerged a kind of shadow
entropy gathering system, with its own tentacles throughout various net
code, added willy nilly.
Stop👏making👏bespoke👏random👏number👏generators👏.
Fortunately, recent advances in random.c mean that we can stop playing
with this sketchiness, and just use get_random_u32(), which is now fast
enough. In micro benchmarks using RDPMC, I'm seeing the same median
cycle count between the two functions, with the mean being _slightly_
higher due to batches refilling (which we can optimize further need be).
However, when doing *real* benchmarks of the net functions that actually
use these random numbers, the mean cycles actually *decreased* slightly
(with the median still staying the same), likely because the additional
prandom code means icache misses and complexity, whereas random.c is
generally already being used by something else nearby.
The biggest benefit of this is that there are many users of prandom who
probably should be using cryptographically secure random numbers. This
makes all of those accidental cases become secure by just flipping a
switch. Later on, we can do a tree-wide cleanup to remove the static
inline wrapper functions that this commit adds.
There are also some low-ish hanging fruits for making this even faster
in the future: a get_random_u16() function for use in the networking
stack will give a 2x performance boost there, using SIMD for ChaCha20
will let us compute 4 or 8 or 16 blocks of output in parallel, instead
of just one, giving us large buffers for cheap, and introducing a
get_random_*_bh() function that assumes irqs are already disabled will
shave off a few cycles for ordinary calls. These are things we can chip
away at down the road.
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When calling dev_fill_forward_path on a pppoe device, the provided destination
address is invalid. In order for the bridge fdb lookup to succeed, the pppoe
code needs to update ctx->daddr to the correct value.
Fix this by storing the address inside struct net_device_path_ctx
Fixes: f6efc675c9 ("net: ppp: resolve forwarding path for bridge pppoe devices")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
skb_defer_free_flush() can consume cpu cycles,
it seems better to call it in the inner loop:
- Potentially frees page/skb that will be reallocated while hot.
- Account for the cpu cycles in the @time_limit determination.
- Keep softnet_data.defer_count small to reduce chances for
skb_attempt_defer_free() to send an IPI.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 68822bdf76 ("net: generalize skb freeing
deferral to per-cpu lists") added another per-cpu
cache of skbs. It was expected to be small,
and an IPI was forced whenever the list reached 128
skbs.
We might need to be able to control more precisely
queue capacity and added latency.
An IPI is generated whenever queue reaches half capacity.
Default value of the new limit is 64.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_defer_free_flush() runs from softirq context,
we have the opportunity to refill the napi_alloc_cache,
and/or use kmem_cache_free_bulk() when this cache is full.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A cpu can observe sd->defer_count reaching 128,
and call smp_call_function_single_async()
Problem is that the remote CPU can clear sd->defer_count
before the IPI is run/acknowledged.
Other cpus can queue more packets and also decide
to call smp_call_function_single_async() while the pending
IPI was not yet delivered.
This is a common issue with smp_call_function_single_async().
Callers must ensure correct synchronization and serialization.
I triggered this issue while experimenting smaller threshold.
Performing the call to smp_call_function_single_async()
under sd->defer_lock protection did not solve the problem.
Commit 5a18ceca63 ("smp: Allow smp_call_function_single_async()
to insert locked csd") replaced an informative WARN_ON_ONCE()
with a return of -EBUSY, which is often ignored.
Test of CSD_FLAG_LOCK presence is racy anyway.
Fixes: 68822bdf76 ("net: generalize skb freeing deferral to per-cpu lists")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow the gro_max_size to exceed a value larger than 65536.
There weren't really any external limitations that prevented this other
than the fact that IPv4 only supports a 16 bit length field. Since we have
the option of adding a hop-by-hop header for IPv6 we can allow IPv6 to
exceed this value and for IPv4 and non-TCP flows we can cap things at 65536
via a constant rather than relying on gro_max_size.
[edumazet] limit GRO_MAX_SIZE to (8 * 65535) to avoid overflows.
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code for gso_max_size was added originally to allow for debugging and
workaround of buggy devices that couldn't support TSO with blocks 64K in
size. The original reason for limiting it to 64K was because that was the
existing limits of IPv4 and non-jumbogram IPv6 length fields.
With the addition of Big TCP we can remove this limit and allow the value
to potentially go up to UINT_MAX and instead be limited by the tso_max_size
value.
So in order to support this we need to go through and clean up the
remaining users of the gso_max_size value so that the values will cap at
64K for non-TCPv6 flows. In addition we can clean up the GSO_MAX_SIZE value
so that 64K becomes GSO_LEGACY_MAX_SIZE and UINT_MAX will now be the upper
limit for GSO_MAX_SIZE.
v6: (edumazet) fixed a compile error if CONFIG_IPV6=n,
in a new sk_trim_gso_size() helper.
netif_set_tso_max_size() caps the requested TSO size
with GSO_MAX_SIZE.
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a followup of previous patch.
Dumping the stack trace is a good start, but printing
basic skb information is probably better.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I have a syzbot report that managed to get a crash in skb_checksum_help()
If syzbot can trigger these BUG(), it makes sense to replace
them with more friendly WARN_ON_ONCE() since skb_checksum_help()
can instead return an error code.
Note that syzbot will still crash there, until real bug is fixed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Drivers should call the TSO setting helper, GSO is controllable
by user space.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Up until commit 46e6b992c2 ("rtnetlink: allow GSO maximums to
be set on device creation") the gso_max_segs and gso_max_size
of a device were not controlled from user space.
The quoted commit added the ability to control them because of
the following setup:
netns A | netns B
veth<->veth eth0
If eth0 has TSO limitations and user wants to efficiently forward
traffic between eth0 and the veths they should copy the TSO
limitations of eth0 onto the veths. This would happen automatically
for macvlans or ipvlan but veth users are not so lucky (given the
loose coupling).
Unfortunately the commit in question allowed users to also override
the limits on real HW devices.
It may be useful to control the max GSO size and someone may be using
that ability (not that I know of any user), so create a separate set
of knobs to reliably record the TSO limitations. Validate the user
requests.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
To make later patches smaller create a helper for inheriting
the TSO limitations of a lower device. The TSO in the name
is not an accident, subsequent patches will replace GSO
with TSO in more names.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most drivers should not have to worry about selecting the right
weight for their NAPI instances and pass NAPI_POLL_WEIGHT.
It'd be best if we didn't require the argument at all and selected
the default internally.
This change prepares the ground for such reshuffling, allowing
for a smooth transition. The following API should remain after
the next release cycle:
netif_napi_add()
netif_napi_add_weight()
netif_napi_add_tx()
netif_napi_add_tx_weight()
Where the _weight() variants take an explicit weight argument.
I opted for a _weight() suffix rather than a __ prefix, because
we use __ in places to mean that caller needs to also issue a
synchronize_net() call.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20220502232703.396351-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Inline dev_queue_xmit() and dev_queue_xmit_accel(), they both are small
proxy functions doing nothing but redirecting the control flow to
__dev_queue_xmit().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I missed a stray return; in net_rx_action(), which very well
is taken whenever trigger_rx_softirq() has been called on
a cpu that is no longer receiving network packets,
or receiving too few of them.
Fixes: 68822bdf76 ("net: generalize skb freeing deferral to per-cpu lists")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20220427204147.1310161-1-eric.dumazet@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The macro dev_core_stats_##FIELD##_inc() disables preemption and invokes
netdev_core_stats_alloc() to return a per-CPU pointer.
netdev_core_stats_alloc() will allocate memory on its first invocation
which breaks on PREEMPT_RT because it requires non-atomic context for
memory allocation.
This can be avoided by enabling preemption in netdev_core_stats_alloc()
assuming the caller always disables preemption.
It might be better to replace local_inc() with this_cpu_inc() now that
dev_core_stats_##FIELD##_inc() gained a preempt-disable section and does
not rely on already disabled preemption. This results in less
instructions on x86-64:
local_inc:
| incl %gs:__preempt_count(%rip) # __preempt_count
| movq 488(%rdi), %rax # _1->core_stats, _22
| testq %rax, %rax # _22
| je .L585 #,
| add %gs:this_cpu_off(%rip), %rax # this_cpu_off, tcp_ptr__
| .L586:
| testq %rax, %rax # _27
| je .L587 #,
| incq (%rax) # _6->a.counter
| .L587:
| decl %gs:__preempt_count(%rip) # __preempt_count
this_cpu_inc(), this patch:
| movq 488(%rdi), %rax # _1->core_stats, _5
| testq %rax, %rax # _5
| je .L591 #,
| .L585:
| incq %gs:(%rax) # _18->rx_dropped
Use unsigned long as type for the counter. Use this_cpu_inc() to
increment the counter. Use a plain read of the counter.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/YmbO0pxgtKpCw4SY@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Logic added in commit f35f821935 ("tcp: defer skb freeing after socket
lock is released") helped bulk TCP flows to move the cost of skbs
frees outside of critical section where socket lock was held.
But for RPC traffic, or hosts with RFS enabled, the solution is far from
being ideal.
For RPC traffic, recvmsg() has to return to user space right after
skb payload has been consumed, meaning that BH handler has no chance
to pick the skb before recvmsg() thread. This issue is more visible
with BIG TCP, as more RPC fit one skb.
For RFS, even if BH handler picks the skbs, they are still picked
from the cpu on which user thread is running.
Ideally, it is better to free the skbs (and associated page frags)
on the cpu that originally allocated them.
This patch removes the per socket anchor (sk->defer_list) and
instead uses a per-cpu list, which will hold more skbs per round.
This new per-cpu list is drained at the end of net_action_rx(),
after incoming packets have been processed, to lower latencies.
In normal conditions, skbs are added to the per-cpu list with
no further action. In the (unlikely) cases where the cpu does not
run net_action_rx() handler fast enough, we use an IPI to raise
NET_RX_SOFTIRQ on the remote cpu.
Also, we do not bother draining the per-cpu list from dev_cpu_dead()
This is because skbs in this list have no requirement on how fast
they should be freed.
Note that we can add in the future a small per-cpu cache
if we see any contention on sd->defer_lock.
Tested on a pair of hosts with 100Gbit NIC, RFS enabled,
and /proc/sys/net/ipv4/tcp_rmem[2] tuned to 16MB to work around
page recycling strategy used by NIC driver (its page pool capacity
being too small compared to number of skbs/pages held in sockets
receive queues)
Note that this tuning was only done to demonstrate worse
conditions for skb freeing for this particular test.
These conditions can happen in more general production workload.
10 runs of one TCP_STREAM flow
Before:
Average throughput: 49685 Mbit.
Kernel profiles on cpu running user thread recvmsg() show high cost for
skb freeing related functions (*)
57.81% [kernel] [k] copy_user_enhanced_fast_string
(*) 12.87% [kernel] [k] skb_release_data
(*) 4.25% [kernel] [k] __free_one_page
(*) 3.57% [kernel] [k] __list_del_entry_valid
1.85% [kernel] [k] __netif_receive_skb_core
1.60% [kernel] [k] __skb_datagram_iter
(*) 1.59% [kernel] [k] free_unref_page_commit
(*) 1.16% [kernel] [k] __slab_free
1.16% [kernel] [k] _copy_to_iter
(*) 1.01% [kernel] [k] kfree
(*) 0.88% [kernel] [k] free_unref_page
0.57% [kernel] [k] ip6_rcv_core
0.55% [kernel] [k] ip6t_do_table
0.54% [kernel] [k] flush_smp_call_function_queue
(*) 0.54% [kernel] [k] free_pcppages_bulk
0.51% [kernel] [k] llist_reverse_order
0.38% [kernel] [k] process_backlog
(*) 0.38% [kernel] [k] free_pcp_prepare
0.37% [kernel] [k] tcp_recvmsg_locked
(*) 0.37% [kernel] [k] __list_add_valid
0.34% [kernel] [k] sock_rfree
0.34% [kernel] [k] _raw_spin_lock_irq
(*) 0.33% [kernel] [k] __page_cache_release
0.33% [kernel] [k] tcp_v6_rcv
(*) 0.33% [kernel] [k] __put_page
(*) 0.29% [kernel] [k] __mod_zone_page_state
0.27% [kernel] [k] _raw_spin_lock
After patch:
Average throughput: 73076 Mbit.
Kernel profiles on cpu running user thread recvmsg() looks better:
81.35% [kernel] [k] copy_user_enhanced_fast_string
1.95% [kernel] [k] _copy_to_iter
1.95% [kernel] [k] __skb_datagram_iter
1.27% [kernel] [k] __netif_receive_skb_core
1.03% [kernel] [k] ip6t_do_table
0.60% [kernel] [k] sock_rfree
0.50% [kernel] [k] tcp_v6_rcv
0.47% [kernel] [k] ip6_rcv_core
0.45% [kernel] [k] read_tsc
0.44% [kernel] [k] _raw_spin_lock_irqsave
0.37% [kernel] [k] _raw_spin_lock
0.37% [kernel] [k] native_irq_return_iret
0.33% [kernel] [k] __inet6_lookup_established
0.31% [kernel] [k] ip6_protocol_deliver_rcu
0.29% [kernel] [k] tcp_rcv_established
0.29% [kernel] [k] llist_reverse_order
v2: kdoc issue (kernel bots)
do not defer if (alloc_cpu == smp_processor_id()) (Paolo)
replace the sk_buff_head with a single-linked list (Jakub)
add a READ_ONCE()/WRITE_ONCE() for the lockless read of sd->defer_list
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20220422201237.416238-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch fixes issue:
* If we install tc filters with act_skbedit in clsact hook.
It doesn't work, because netdev_core_pick_tx() overwrites
queue_mapping.
$ tc filter ... action skbedit queue_mapping 1
And this patch is useful:
* We can use FQ + EDT to implement efficient policies. Tx queues
are picked by xps, ndo_select_queue of netdev driver, or skb hash
in netdev_core_pick_tx(). In fact, the netdev driver, and skb
hash are _not_ under control. xps uses the CPUs map to select Tx
queues, but we can't figure out which task_struct of pod/containter
running on this cpu in most case. We can use clsact filters to classify
one pod/container traffic to one Tx queue. Why ?
In containter networking environment, there are two kinds of pod/
containter/net-namespace. One kind (e.g. P1, P2), the high throughput
is key in these applications. But avoid running out of network resource,
the outbound traffic of these pods is limited, using or sharing one
dedicated Tx queues assigned HTB/TBF/FQ Qdisc. Other kind of pods
(e.g. Pn), the low latency of data access is key. And the traffic is not
limited. Pods use or share other dedicated Tx queues assigned FIFO Qdisc.
This choice provides two benefits. First, contention on the HTB/FQ Qdisc
lock is significantly reduced since fewer CPUs contend for the same queue.
More importantly, Qdisc contention can be eliminated completely if each
CPU has its own FIFO Qdisc for the second kind of pods.
There must be a mechanism in place to support classifying traffic based on
pods/container to different Tx queues. Note that clsact is outside of Qdisc
while Qdisc can run a classifier to select a sub-queue under the lock.
In general recording the decision in the skb seems a little heavy handed.
This patch introduces a per-CPU variable, suggested by Eric.
The xmit.skip_txqueue flag is firstly cleared in __dev_queue_xmit().
- Tx Qdisc may install that skbedit actions, then xmit.skip_txqueue flag
is set in qdisc->enqueue() though tx queue has been selected in
netdev_tx_queue_mapping() or netdev_core_pick_tx(). That flag is cleared
firstly in __dev_queue_xmit(), is useful:
- Avoid picking Tx queue with netdev_tx_queue_mapping() in next netdev
in such case: eth0 macvlan - eth0.3 vlan - eth0 ixgbe-phy:
For example, eth0, macvlan in pod, which root Qdisc install skbedit
queue_mapping, send packets to eth0.3, vlan in host. In __dev_queue_xmit() of
eth0.3, clear the flag, does not select tx queue according to skb->queue_mapping
because there is no filters in clsact or tx Qdisc of this netdev.
Same action taked in eth0, ixgbe in Host.
- Avoid picking Tx queue for next packet. If we set xmit.skip_txqueue
in tx Qdisc (qdisc->enqueue()), the proper way to clear it is clearing it
in __dev_queue_xmit when processing next packets.
For performance reasons, use the static key. If user does not config the NET_EGRESS,
the patch will not be compiled.
+----+ +----+ +----+
| P1 | | P2 | | Pn |
+----+ +----+ +----+
| | |
+-----------+-----------+
|
| clsact/skbedit
| MQ
v
+-----------+-----------+
| q0 | q1 | qn
v v v
HTB/FQ HTB/FQ ... FIFO
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Talal Ahmad <talalahmad@google.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Antoine Tenart <atenart@kernel.org>
Cc: Wei Wang <weiwan@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
As David Ahern suggested, the reasons for skb drops should be more
general and not be code based.
Therefore, rename SKB_DROP_REASON_PTYPE_ABSENT to
SKB_DROP_REASON_UNHANDLED_PROTO, which is used for the cases of no
L3 protocol handler, no L4 protocol handler, version extensions, etc.
From previous discussion, now we have the aim to make these reasons
more abstract and users based, avoiding code based.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Increment rx_otherhost_dropped counter when packet dropped due to
mismatched dest MAC addr.
An example when this drop can occur is when manually crafting raw
packets that will be consumed by a user space application via a tap
device. For testing purposes local traffic was generated using trafgen
for the client and netcat to start a server
Tested: Created 2 netns, sent 1 packet using trafgen from 1 to the other
with "{eth(daddr=$INCORRECT_MAC...}", verified that iproute2 showed the
counter was incremented. (Also had to modify iproute2 to show the stat,
additional patch for that coming next.)
Signed-off-by: Jeffrey Ji <jeffreyji@google.com>
Reviewed-by: Brian Vazquez <brianvv@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220406172600.1141083-1-jeffreyjilinux@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There's a number of functions and static variables used
under net/core/ but not from the outside. We currently
dump most of them into netdevice.h. That bad for many
reasons:
- netdevice.h is very cluttered, hard to figure out
what the APIs are;
- netdevice.h is very long;
- we have to touch netdevice.h more which causes expensive
incremental builds.
Create a header under net/core/ and move some declarations.
The new header is also a bit of a catch-all but that's
fine, if we create more specific headers people will
likely over-think where their declaration fit best.
And end up putting them in netdevice.h, again.
More work should be done on splitting netdevice.h into more
targeted headers, but that'd be more time consuming so small
steps.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We have a bunch of functions which are only used under
net/core/ yet they get exported. Remove the exports.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This allows hardware flow offloading from Ethernet to WLAN on MT7622 SoC
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: David S. Miller <davem@davemloft.net>
In [1], Will raised a potential issue that the cfg80211 code,
which does (from a locking perspective)
rtnl_lock()
wiphy_lock()
rtnl_unlock()
might be suspectible to ABBA deadlocks, because rtnl_unlock()
calls netdev_run_todo(), which might end up calling rtnl_lock()
again, which could then deadlock (see the comment in the code
added here for the scenario).
Some back and forth and thinking ensued, but clearly this can't
happen if the net_todo_list is empty at the rtnl_unlock() here.
Clearly, the code here cannot actually put an entry on it, and
all other users of rtnl_unlock() will empty it since that will
always go through netdev_run_todo(), emptying the list.
So the only other way to get there would be to add to the list
and then unlock the RTNL without going through rtnl_unlock(),
which is only possible through __rtnl_unlock(). However, this
isn't exported and not used in many places, and none of them
seem to be able to unregister before using it.
Therefore, add a WARN_ON() in the code to ensure this invariant
won't be broken, so that the cfg80211 (or any similar) code
stays safe.
[1] https://lore.kernel.org/r/Yjzpo3TfZxtKPMAG@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220404113847.0ee02e4a70da.Ic73d206e217db20fd22dcec14fe5442ca732804b@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The lockdep annotation lockdep_assert_softirq_will_run() expects that
either hard or soft interrupts are disabled because both guaranty that
the "raised" soft-interrupts will be processed once the context is left.
This triggers in flush_smp_call_function_from_idle() but it this case it
explicitly calls do_softirq() in case of pending softirqs.
Revert the "softirq will run" annotation in ____napi_schedule() and move
the check back to __netif_rx() as it was. Keep the IRQ-off assert in
____napi_schedule() because this is always required.
Fixes: fbd9a2ceba ("net: Add lockdep asserts to ____napi_schedule().")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/YjhD3ZKWysyw8rc6@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Network drivers can call to netif_get_num_default_rss_queues to get the
default number of receive queues to use. Right now, this default number
is min(8, num_online_cpus()).
Instead, as suggested by Jakub, use the number of physical cores divided
by 2 as a way to avoid wasting CPU resources and to avoid using both CPU
threads, but still allowing to scale for high-end processors with many
cores.
As an exception, select 2 queues for processors with 2 cores, because
otherwise it won't take any advantage of RSS despite being SMP capable.
Tested: Processor Intel Xeon E5-2620 (2 sockets, 6 cores/socket, 2
threads/core). NIC Broadcom NetXtreme II BCM57810 (10GBps). Ran some
tests with `perf stat iperf3 -R`, with parallelisms of 1, 8 and 24,
getting the following results:
- Number of queues: 6 (instead of 8)
- Network throughput: not affected
- CPU usage: utilized 0.05-0.12 CPUs more than before (having 24 CPUs
this is only 0.2-0.5% higher)
- Reduced the number of context switches by 7-50%, being more noticeable
when using a higher number of parallel threads.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
Link: https://lore.kernel.org/r/20220315091832.13873-1-ihuguet@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Kuniyuki Iwashima
Jakub Kicinski
Zhengchao Shao
Johan Almbladh
Eric Dumazet
Linus Torvalds
Jason A. Donenfeld
Felix Fietkau
Alexander Duyck
Pavel Begunkov
Sebastian Andrzej Siewior
Tonghao Zhang
Menglong Dong
Jeffrey Ji
Johannes Berg
Íñigo Huguet