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* [PATCH v2 net-next 0/2] raw: RCU conversion
@ 2022-06-18  3:47 Eric Dumazet
  2022-06-18  3:47 ` [PATCH v2 net-next 1/2] raw: use more conventional iterators Eric Dumazet
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Eric Dumazet @ 2022-06-18  3:47 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: netdev, Eric Dumazet, Eric Dumazet

From: Eric Dumazet <edumazet@google.com>

Using rwlock in networking code is extremely risky.
writers can starve if enough readers are constantly
grabing the rwlock.

I thought rwlock were at fault and sent this patch:

https://lkml.org/lkml/2022/6/17/272

But Peter and Linus essentially told me rwlock had to be unfair.

We need to get rid of rwlock in networking stacks.

Without this conversion, following script triggers soft lockups:

for i in {1..48}
do
 ping -f -n -q 127.0.0.1 &
 sleep 0.1
done

Next step will be to convert ping sockets to RCU as well.

v2: small issue in first patch, detected by kernel bot
    Polish second patch in net/ipv4/raw_diag.c

Eric Dumazet (2):
  raw: use more conventional iterators
  raw: convert raw sockets to RCU

 include/net/raw.h   |  16 +++--
 include/net/rawv6.h |   7 +-
 net/ipv4/af_inet.c  |   2 +
 net/ipv4/raw.c      | 162 +++++++++++++++++---------------------------
 net/ipv4/raw_diag.c |  53 ++++++++-------
 net/ipv6/af_inet6.c |   3 +
 net/ipv6/raw.c      | 119 ++++++++++++--------------------
 7 files changed, 157 insertions(+), 205 deletions(-)

-- 
2.36.1.476.g0c4daa206d-goog


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-06-19  9:14 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-18  3:47 [PATCH v2 net-next 0/2] raw: RCU conversion Eric Dumazet
2022-06-18  3:47 ` [PATCH v2 net-next 1/2] raw: use more conventional iterators Eric Dumazet
2022-06-18  3:47 ` [PATCH v2 net-next 2/2] raw: convert raw sockets to RCU Eric Dumazet
2022-06-19  9:10 ` [PATCH v2 net-next 0/2] raw: RCU conversion patchwork-bot+netdevbpf

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