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From: Vallo Kallaste <kalts@estpak.ee>
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Subject: Re: s6-log taking 100% CPU
Date: Thu, 13 Dec 2012 16:36:54 +0200
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To: Vallo Kallaste <kalts@estpak.ee>
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On Thu, Dec 13, 2012 at 04:19:25PM +0200, Vallo Kallaste
<kalts@estpak.ee> wrote:

> I have noticed that s6-log enters busyloop after failing to rotate
> the log. Some data:
> 
>  * I don't have strace output at hand, but from memory it was
>    infinite stream of identical poll() related lines.

I have reproduced it and here's the strace output:

poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=0, events=0}, {fd=5, events=POLLIN|POLLHUP}, {fd=4, events=POLLOUT}], 3, -1) = 1 ([{fd=4, revents=POLLOUT}])
...
ad infinitum

BR,
-- 
Vallo