406f42fa0d
The source of most of the slow down is the `dev_addr_lists.c` module, which mainatins a linked list of HW addresses. When using IPv6, this list grows for each IPv6 address added on a VLAN, since each IPv6 address has a multicast HW address associated with it. When performing any modification to the involved links, this list is traversed many times, often for nothing, all while holding the RTNL lock. Instead, this patch adds an auxilliary rbtree which cuts down traversal time significantly. Performance can be seen with the following script: #!/bin/bash ip netns del test || true 2>/dev/null ip netns add test echo 1 | ip netns exec test tee /proc/sys/net/ipv6/conf/all/keep_addr_on_down > /dev/null set -e ip -n test link add foo type veth peer name bar ip -n test link add b1 type bond ip -n test link add florp type vrf table 10 ip -n test link set bar master b1 ip -n test link set foo up ip -n test link set bar up ip -n test link set b1 up ip -n test link set florp up VLAN_COUNT=1500 BASE_DEV=b1 echo Creating vlans ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link add link $BASE_DEV name foo.\$i type vlan id \$i; done" echo Bringing them up ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link set foo.\$i up; done" echo Assiging IPv6 Addresses ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test address add dev foo.\$i 2000::\$i/64; done" echo Attaching to VRF ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link set foo.\$i master florp; done" On an Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz machine, the performance before the patch is (truncated): Creating vlans real 108.35 Bringing them up real 4.96 Assiging IPv6 Addresses real 19.22 Attaching to VRF real 458.84 After the patch: Creating vlans real 5.59 Bringing them up real 5.07 Assiging IPv6 Addresses real 5.64 Attaching to VRF real 25.37 Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Lu Wei <luwei32@huawei.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Gilad Naaman <gnaaman@drivenets.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.