linux-kernel - epoll_wait inaccurate timeout

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Date:   Fri, 2 Dec 2016 15:11:32 +0300
From:   Dmitry Banschikov <me@...que.spb.ru>
To:     linux-kernel@...r.kernel.org
Subject: epoll_wait inaccurate timeout

Hi!

I have a problem caused by inaccurate timeouts in epoll_wait(2).
Here are some parts of strace -tt output:

22578 09:33:46.959791 epoll_wait(5,  <unfinished ...>
22578 09:33:50.010794 <... epoll_wait resumed> [], 128, 1498) = 0
...
22034 09:35:07.686896 epoll_wait(5,  <unfinished ...>
22034 09:35:09.482526 <... epoll_wait resumed> [{EPOLLIN,
{u32=151458248, u64=151458248}}], 128, 362) = 1
...
22036 09:35:41.433241 epoll_wait(5,  <unfinished ...>
22036 09:35:43.176881 <... epoll_wait resumed> [], 128, 97) = 0

In each example epoll_wait is blocked for too longer then asked in timeout.

Is it normal?

Please CC me.



-- 

Dmitry Banschikov