On Fri, Jan 12, 2018 at 10:13:55AM -0600, Samuel Reed wrote:
> Excellent! Please let me know if there's any other output you'd like
> from this machine.
>
> Strace on that new process shows thousands of these types of syscalls,
> which vary slightly,
>
> epoll_wait(3, {{EPOLLIN, {u32=206, u64=206}}}, 200, 239) = 1
If the u32 value almost doesn't vary, that's an uncaught event. We've
got a report for this that we've just fixed yesterday which started to
appear after the system was upgraded with Meltdown fixes. That seems
unrelated but reverting made the problem disappear.
> and these:
>
> epoll_wait(3, {}, 200, 0) = 0
This one used to appear in yesterday's report though it could be caused
by other bugs as well. That's the one I predicted.
> There is also something of a cascade (each repeats about 10-20x before
> the next):
>
> epoll_wait(3, {{EPOLLIN, {u32=47, u64=47}}}, 200, 71) = 1
> epoll_wait(3, {{EPOLLIN, {u32=93, u64=93}}, {EPOLLIN, {u32=656,
> u64=656}}}, 200, 65) = 2
> epoll_wait(3, {{EPOLLIN, {u32=93, u64=93}}, {EPOLLIN, {u32=656,
> u64=656}}, {EPOLLIN, {u32=227, u64=227}}}, 200, 0) = 3
> epoll_wait(3, {{EPOLLIN, {u32=93, u64=93}}, {EPOLLIN, {u32=656,
> u64=656}}, {EPOLLIN, {u32=227, u64=227}}, {EPOLLIN, {u32=785,
> u64=785}}}, 200, 65) = 4
> epoll_wait(3, {{EPOLLIN, {u32=93, u64=93}}, {EPOLLIN, {u32=656,
> u64=656}}, {EPOLLIN, {u32=227, u64=227}}, {EPOLLIN, {u32=785, u64=785}},
> {EPOLLIN, {u32=639, u64=639}}}, 200, 64) = 5
>
> I've seen it go as deep as 15. The trace is absolutely dominated by these.
OK that's very interesting. Just in doubt, please update to latest
1.8-git to see if it makes this issue disappear.
Thanks,
Willy
