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  1. 24 4月, 2020 8 次提交
    • E
      net/mlx4_en: use napi_complete_done() in TX completion · cf4058db
      由 Eric Dumazet 提交于 
      In order to benefit from the new napi_defer_hard_irqs feature,
we need to use napi_complete_done() variant in this driver.

RX path is already using it, this patch implements TX completion side.

mlx4_en_process_tx_cq() now returns the amount of retired packets,
instead of a boolean, so that mlx4_en_poll_tx_cq() can pass
this value to napi_complete_done().
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf4058db
    • E
      net: napi: use READ_ONCE()/WRITE_ONCE() · 7e417a66
      由 Eric Dumazet 提交于 
      gro_flush_timeout and napi_defer_hard_irqs can be read
from napi_complete_done() while other cpus write the value,
whithout explicit synchronization.

Use READ_ONCE()/WRITE_ONCE() to annotate the races.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7e417a66
    • E
      net: napi: add hard irqs deferral feature · 6f8b12d6
      由 Eric Dumazet 提交于 
      Back in commit 3b47d303 ("net: gro: add a per device gro flush timer")
we added the ability to arm one high resolution timer, that we used
to keep not-complete packets in GRO engine a bit longer, hoping that further
frames might be added to them.

Since then, we added the napi_complete_done() interface, and commit
364b6055 ("net: busy-poll: return busypolling status to drivers")
allowed drivers to avoid re-arming NIC interrupts if we made a promise
that their NAPI poll() handler would be called in the near future.

This infrastructure can be leveraged, thanks to a new device parameter,
which allows to arm the napi hrtimer, instead of re-arming the device
hard IRQ.

We have noticed that on some servers with 32 RX queues or more, the chit-chat
between the NIC and the host caused by IRQ delivery and re-arming could hurt
throughput by ~20% on 100Gbit NIC.

In contrast, hrtimers are using local (percpu) resources and might have lower
cost.

The new tunable, named napi_defer_hard_irqs, is placed in the same hierarchy
than gro_flush_timeout (/sys/class/net/ethX/)

By default, both gro_flush_timeout and napi_defer_hard_irqs are zero.

This patch does not change the prior behavior of gro_flush_timeout
if used alone : NIC hard irqs should be rearmed as before.

One concrete usage can be :

echo 20000 >/sys/class/net/eth1/gro_flush_timeout
echo 10 >/sys/class/net/eth1/napi_defer_hard_irqs

If at least one packet is retired, then we will reset napi counter
to 10 (napi_defer_hard_irqs), ensuring at least 10 periodic scans
of the queue.

On busy queues, this should avoid NIC hard IRQ, while before this patch IRQ
avoidance was only possible if napi->poll() was exhausting its budget
and not call napi_complete_done().

This feature also can be used to work around some non-optimal NIC irq
coalescing strategies.

Having the ability to insert XX usec delays between each napi->poll()
can increase cache efficiency, since we increase batch sizes.

It also keeps serving cpus not idle too long, reducing tail latencies.
Co-developed-by: NLuigi Rizzo <lrizzo@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6f8b12d6
    • D
      Merge branch 'qed-aer' · e6acd2b6
      由 David S. Miller 提交于 
      Sudarsana Reddy Kalluru says:

====================
qed*: Add support for pcie advanced error recovery.

The patch series adds qed/qede driver changes for PCIe Advanced Error
Recovery (AER) support.
Patch (1) adds qed changes to enable the device to send error messages
to root port when detected.
Patch (2) adds qede support for handling the detected errors (AERs).

Changes from previous version:
-------------------------------
v2: use pci_num_vf() instead of caching the value in edev.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e6acd2b6
    • S
      qede: Add support for handling the pcie errors. · 731815e7
      由 Sudarsana Reddy Kalluru 提交于 
      The error recovery is handled by management firmware (MFW) with the help of
qed/qede drivers. Upon detecting the errors, driver informs MFW about this
event which in turn starts a recovery process. MFW sends ERROR_RECOVERY
notification to the driver which performs the required cleanup/recovery
from the driver side.
Signed-off-by: NSudarsana Reddy Kalluru <skalluru@marvell.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      731815e7
    • S
      qed: Enable device error reporting capability. · 2196d831
      由 Sudarsana Reddy Kalluru 提交于 
      The patch enables the device to send error messages to root port when
an error is detected.
Signed-off-by: NSudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: NAriel Elior <aelior@marvell.com>
Signed-off-by: NIgor Russkikh <irusskikh@marvell.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2196d831
    • A
      net: dsa: add GRO support via gro_cells · e131a563
      由 Alexander Lobakin 提交于 
      gro_cells lib is used by different encapsulating netdevices, such as
geneve, macsec, vxlan etc. to speed up decapsulated traffic processing.
CPU tag is a sort of "encapsulation", and we can use the same mechs to
greatly improve overall DSA performance.
skbs are passed to the GRO layer after removing CPU tags, so we don't
need any new packet offload types as it was firstly proposed by me in
the first GRO-over-DSA variant [1].

The size of struct gro_cells is sizeof(void *), so hot struct
dsa_slave_priv becomes only 4/8 bytes bigger, and all critical fields
remain in one 32-byte cacheline.
The other positive side effect is that drivers for network devices
that can be shipped as CPU ports of DSA-driven switches can now use
napi_gro_frags() to pass skbs to kernel. Packets built that way are
completely non-linear and are likely being dropped without GRO.

This was tested on to-be-mainlined-soon Ethernet driver that uses
napi_gro_frags(), and the overall performance was on par with the
variant from [1], sometimes even better due to minimal overhead.
net.core.gro_normal_batch tuning may help to push it to the limit
on particular setups and platforms.

iperf3 IPoE VLAN NAT TCP forwarding (port1.218 -> port0) setup
on 1.2 GHz MIPS board:

5.7-rc2 baseline:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  9.00 GBytes  644 Mbits/sec  413  sender
[ 5]  0.00-120.00 sec  8.99 GBytes  644 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       7097731     7097702
port0      426050      6671829
port1      6671681     425862
port1.218  6671677     425851

With this patch:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  12.2 GBytes  870 Mbits/sec  122  sender
[ 5]  0.00-120.00 sec  12.2 GBytes  870 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       9474792     9474777
port0      455200      353288
port1      9019592     455035
port1.218  353144      455024

v2:
 - Add some performance examples in the commit message;
 - No functional changes.

[1] https://lore.kernel.org/netdev/20191230143028.27313-1-alobakin@dlink.ru/Signed-off-by: NAlexander Lobakin <bloodyreaper@yandex.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e131a563
    • F
      ipv6: Honor all IPv6 PIO Valid Lifetime values · b75326c2
      由 Fernando Gont 提交于 
      RFC4862 5.5.3 e) prevents received Router Advertisements from reducing
the Valid Lifetime of configured addresses to less than two hours, thus
preventing hosts from reacting to the information provided by a router
that has positive knowledge that a prefix has become invalid.

This patch makes hosts honor all Valid Lifetime values, as per
draft-gont-6man-slaac-renum-06, Section 4.2. This is meant to help
mitigate the problem discussed in draft-ietf-v6ops-slaac-renum.

Note: Attacks aiming at disabling an advertised prefix via a Valid
Lifetime of 0 are not really more harmful than other attacks
that can be performed via forged RA messages, such as those
aiming at completely disabling a next-hop router via an RA that
advertises a Router Lifetime of 0, or performing a Denial of
Service (DoS) attack by advertising illegitimate prefixes via
forged PIOs.  In scenarios where RA-based attacks are of concern,
proper mitigations such as RA-Guard [RFC6105] [RFC7113] should
be implemented.
Signed-off-by: NFernando Gont <fgont@si6networks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b75326c2
  3. 23 4月, 2020 32 次提交