| Message ID | 20241021102102.2560279-1-gnaaman@drivenets.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | neighbour: Improve neigh_flush_dev performance | expand |
On 10/21, Gilad Naaman wrote: > This patchsets improves the performance of neigh_flush_dev. > > Currently, the only way to implement it requires traversing > all neighbours known to the kernel, across all network-namespaces. > > This means that some flows are slowed down as a function of neighbour-scale, > even if the specific link they're handling has little to no neighbours. > > In order to solve this, this patchset adds a netdev->neighbours list, > as well as making the original linked-list doubly-, so that it is > possible to unlink neighbours without traversing the hash-bucket to > obtain the previous neighbour. > > The original use-case we encountered was mass-deletion of links (12K > VLANs) while there are 50K ARPs and 50K NDPs in the system; though the > slowdowns would also appear when the links are set down. > > Changes in v6: > > - Reverse changes to mellanox driver > - Rename iteration macros to emphasize `in_bucket` > - Remove now-unused variables and parameters > > Gilad Naaman (6): > neighbour: Add hlist_node to struct neighbour > neighbour: Define neigh_for_each_in_bucket > neighbour: Convert seq_file functions to use hlist > neighbour: Convert iteration to use hlist+macro > neighbour: Remove bare neighbour::next pointer > neighbour: Create netdev->neighbour association > > .../networking/net_cachelines/net_device.rst | 1 + > include/linux/netdevice.h | 7 + > include/net/neighbour.h | 24 +- > include/net/neighbour_tables.h | 12 + > net/core/neighbour.c | 338 ++++++++---------- > net/ipv4/arp.c | 2 +- > 6 files changed, 175 insertions(+), 209 deletions(-) > create mode 100644 include/net/neighbour_tables.h Seems like the series triggers a bunch of GPFs from tools/testing/selftests/net/fib_tests.sh: [ 698.336499] Oops: general protection fault, probably for non-canonical address 0xdead000000000122: 0000 [#1] PREEMPT SMP NOPTI ... [ 698.336743] RIP: 0010:neigh_flush_dev.isra.0+0x5d/0x1a0 ... [ 698.337531] Call Trace: [ 698.337560] <TASK> [ 698.337586] ? die_addr+0x37/0x90 [ 698.337626] ? exc_general_protection+0x1b7/0x3b0 [ 698.337674] ? asm_exc_general_protection+0x26/0x30 [ 698.337721] ? neigh_flush_dev.isra.0+0x5d/0x1a0 [ 698.337760] __neigh_ifdown.isra.0+0x33/0x120 [ 698.337798] neigh_ifdown+0x10/0x20 [ 698.337827] fib_netdev_event+0xa1/0x1a0 [ 698.337868] notifier_call_chain+0x5b/0xd0 [ 698.337907] dev_close_many+0xef/0x160 [ 698.337946] unregister_netdevice_many_notify+0x155/0x910 [ 698.337990] ? sock_def_readable+0x14/0xc0 [ 698.338024] ? __netlink_sendskb+0x64/0x90 [ 698.338061] rtnl_dellink+0x14d/0x3a0 [ 698.338101] ? rtnl_getlink+0x376/0x400 [ 698.338139] ? __rtnl_unlock+0x37/0x70 [ 698.338170] ? netdev_run_todo+0x64/0x550 [ 698.338201] rtnetlink_rcv_msg+0x15d/0x410 [ 698.338234] ? get_page_from_freelist+0xf04/0x10c0 [ 698.338278] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 698.338315] netlink_rcv_skb+0x58/0x110 [ 698.338351] netlink_unicast+0x247/0x370 [ 698.338384] netlink_sendmsg+0x1bf/0x3e0 [ 698.338414] ____sys_sendmsg+0x2bc/0x320 https://netdev.bots.linux.dev/contest.html?branch=net-next-2024-10-21--15-00&executor=vmksft-net&pw-n=0&pass=0 Can you please take a look? --- pw-bot: cr
> Seems like the series triggers a bunch of GPFs from > tools/testing/selftests/net/fib_tests.sh: > > <snip> > > Can you please take a look? Hey, thank you, it seems like I botched it when rebasing the patch.