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Zhu Yanjun 5d8876e2c2 net: forcedeth: add xmit_more support
This change adds support for xmit_more based on the igb commit 6f19e12f62
("igb: flush when in xmit_more mode and under descriptor pressure") and
commit 6b16f9ee89 ("net: move skb->xmit_more hint to softnet data") that
were made to igb to support this feature. The function netif_xmit_stopped
is called to check whether transmit queue on device is currently unable to
send to determine whether we must write the tail because we can add no
further buffers.

When normal packets and/or xmit_more packets fill up tx_desc, it is
necessary to trigger NIC tx reg.

Following the advice from David Miller and Jakub Kicinski, after the
xmit_more feature is added, the following scenario will occur.

         |
   xmit_more packets
         |
   DMA_MAPPING
         |
   DMA_MAPPING error check
         |
   xmit_more packets already in HW xmit queue
         |

In the above scenario, if DMA_MAPPING error occurrs, the xmit_more packets
already in HW xmit queue will also be dropped. This is different from the
behavior before xmit_more feature. So it is necessary to trigger NIC HW tx
reg in the above scenario.

To the non-xmit_more packets, the above scenario will not occur.

Tested:
  - pktgen (xmit_more packets) SMP x86_64 ->
    Test command:
    ./pktgen_sample03_burst_single_flow.sh ... -b 8 -n 1000000
    Test results:
    Params:
    ...
    burst: 8
    ...
    Result: OK: 12194004(c12188996+d5007) usec, 1000001 (1500byte,0frags)
    82007pps 984Mb/sec (984084000bps) errors: 0

  - iperf (normal packets) SMP x86_64 ->
    Test command:
    Server: iperf -s
    Client: iperf -c serverip
    Result:
    TCP window size: 85.0 KByte (default)
    ------------------------------------------------------------
    [ ID] Interval       Transfer     Bandwidth
    [  3]  0.0-10.0 sec  1.10 GBytes   942 Mbits/sec

CC: Joe Jin <joe.jin@oracle.com>
CC: JUNXIAO_BI <junxiao.bi@oracle.com>
Reported-and-tested-by: Nan san <nan.1986san@gmail.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 10:22:31 -08:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-11-02 15:29:58 -07:00
block iocost: don't nest spin_lock_irq in ioc_weight_write() 2019-10-31 11:40:57 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation wireless-drivers-next patches for 5.5 2019-11-05 18:36:35 -08:00
drivers net: forcedeth: add xmit_more support 2019-11-06 10:22:31 -08:00
fs NFS Client Bugfixes for Linux 5.4-rc6 2019-11-01 17:37:44 -07:00
include net_sched: add TCA_STATS_PKT64 attribute 2019-11-05 18:20:55 -08:00
init init: Support mounting root file systems over SMB 2019-10-02 12:15:15 -04:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-11-02 15:29:58 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-11-02 15:29:58 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm uaccess: Add strict non-pagefault kernel-space read function 2019-11-02 12:39:12 -07:00
net This feature/cleanup patchset includes the following patches: 2019-11-05 18:33:05 -08:00
samples bpf, samples: Use bpf_probe_read_user where appropriate 2019-11-02 12:39:13 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
sound ALSA: timer: Fix mutex deadlock at releasing card 2019-10-30 22:54:56 +01:00
tools selftests: bpf: log direct file writes 2019-11-06 09:59:58 -08:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt kvm: call kvm_arch_destroy_vm if vm creation fails 2019-10-31 12:13:16 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap A few MIPS fixes: 2019-10-26 19:43:12 -04:00
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
Makefile Linux 5.4-rc5 2019-10-27 13:19:19 -04:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.