From: Omar Kilani <omar.kilani@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Strange issues with epoll since 5.0
Date: Mon, 15 Apr 2019 11:02:42 -0700 [thread overview]
Message-ID: <CA+8F9hicnF=kvjXPZFQy=Pa2HJUS3JS+G9VswFHNQQynPMHGVQ@mail.gmail.com> (raw)
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
next reply other threads:[~2019-04-15 18:02 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 18:02 Omar Kilani [this message]
2019-04-24 19:39 ` Strange issues with epoll since 5.0 Eric Wong
2019-04-24 21:34 ` Davidlohr Bueso
2019-04-24 21:52 ` Davidlohr Bueso
2019-04-27 9:33 ` Eric Wong
2019-04-27 23:31 ` Deepa Dinamani
2019-04-28 0:48 ` Eric Wong
2019-04-29 20:47 ` Davidlohr Bueso
2019-04-29 21:04 ` Eric Wong
2019-04-30 21:07 ` Deepa Dinamani
2019-05-01 2:14 ` Eric Wong
2019-05-01 2:26 ` Eric Wong
2019-05-01 7:39 ` Eric Wong
2019-05-01 18:37 ` Deepa Dinamani
2019-05-01 20:48 ` Eric Wong
2019-05-01 20:53 ` Deepa Dinamani
2019-05-03 0:01 ` Deepa Dinamani
2019-05-03 2:34 ` Eric Wong
2019-05-03 3:34 ` Davidlohr Bueso
2019-05-03 3:42 ` [PATCH] signal: Adjust error codes according to restore_user_sigmask() Deepa Dinamani
2019-05-03 6:34 ` Eric Wong
2019-05-03 18:21 ` Deepa Dinamani
2019-05-03 19:51 ` Davidlohr Bueso
2019-05-03 22:53 ` Deepa Dinamani
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