Bug 291713 – x11-misc/synergy-1.3.1-r1 hogs CPU

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Caleb Jorden 2009-11-03 14:45:38 UTC]

I upgraded to x11-misc/synergy-1.3.1-r1 today, and found that when I start it the same way I always do: "synergys -a localhost", the process takes up 100% of one of my processing cores.  I masked -r1, and re-installed x11-misc/synergy-1.3.1, and the problem goes away.  My synergy config is:

# sample synergy configuration file
#
# comments begin with the # character and continue to the end of
# line.  comments may appear anywhere the syntax permits.

section: screens
        c001208133:
        c001063625:
        c001121832:
end

section: links
        c001208133:
                left = c001063625
                right = c001121832
        c001063625:
                right = c001208133
        c001121832:
                left = c001208133
end

section: aliases
        # curly is also known as shemp
#       curly:
#               shemp
end

my system:
Linux c001208133 2.6.30-gentoo-r8 #1 SMP Mon Oct 26 15:17:42 CDT 2009 i686 Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz GenuineIntel GNU/Linux

I did an strace on the running process, and got this output:


read(3, 0x8e77e18, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({1257258631, 630562}, NULL) = 0
read(3, 0x8e77e18, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({1257258631, 630597}, NULL) = 0
read(3, 0x8e77e18, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({1257258631, 630632}, NULL) = 0

repeats forever, very fast.

Reproducible: Always

Steps to Reproduce:
1. emerge synergy-1.3.1-r1
2. run synergys -a localhost
3. watch CPU in top or gkrellm

Actual Results:  
Processor is kept at 100%

Expected Results:  
Processor should stay at 0%

[Comment 1 Juan Francisco Giordana 2009-11-03 18:17:14 UTC]

I experienced the same problem with this version on ~amd64.

The CPU usage problem disappears once a client connects.

[Comment 2 Alex Alexander (RETIRED) 2009-11-09 00:51:41 UTC]

This happens here as well. However -r1 fixes an issue with systems using xcb.

Is it working ok for you after a client connects?

[Comment 3 Jozef Siska 2010-07-19 15:35:50 UTC]

Same problem here on ~amd64. 1.3.1-r1 without a connected client uses 100% cpu. When a client connects, the cpu usage gets to normal, after the last client disconnects, it is back at 100%.

I found a similar fedora bug:
https://bugzilla.redhat.com/show_bug.cgi?id=471259

The patch there solved the problem for me.

[Comment 4 Alex Alexander (RETIRED) 2010-07-19 18:07:40 UTC]

I added the patch in x11-misc/synergy-1.3.1-r2.

Thanks :)

+  19 Jul 2010; Alex Alexander <[e-mail]> +synergy-1.3.1-r2.ebuild,
+  +files/synergy-1.3.1-infinite-timeout-fix.patch:
+  fixed bug #291713. Thanks to Jozef Siska for pointing to the patch :)