Messages in this thread | | | From | Omar Kilani <> | Date | Mon, 15 Apr 2019 11:02:42 -0700 | Subject | Strange issues with epoll since 5.0 |
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Hi there,
I’m still trying to piece together a reproducible test that triggers this, but I wanted to post in case someone goes “hmmm... change X might have done this”.
Basically, something’s broken (or at least, has changed enough to cause problems in user space) in epoll since 5.0. It’s still broken in 5.1-rc5.
It doesn’t happen 100% of the time. It’s sort of hard to pin down but I’ve observed the following:
* nginx not accepting connections under load * A java app which uses netty / NIO having strange writability semantics on channels, which confuses netty / java enough to not properly flush written data on the socket.
I went and tested these Linux kernels:
4.20.17 4.19.32 4.14.111
And the issue(s) do not show up there.
I’m still actively chasing this up, and will report back — I haven’t touched kernel code in 15 years so I’m a little rusty. :)
Regards, Omar
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