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Re: [Xen-devel] Floating Point Exception



Well, I searched through the history of the code for that rpmsw.c file in the rpm source code. That sum_cycles stuff looks like it was added on 04-07-2003 and it was ripped out on 4-21-2008. I haven't updated my server since probably January and I bet if I update my rpm to the latest version, the problem is gone. Thanks for you help on this!

Here is the site with the diff's.
http://devel.linux.duke.edu/gitweb/?p=rpm.git;a=history;f=rpmio/rpmsw.c;h=2a6d70af4a069b2f18ba6bf6046d1fef927c7c9d;hb=HEAD


On Jul 11, 2008, at 12:21 PM, Samuel Thibault wrote:

Cody Jarrett, le Fri 11 Jul 2008 11:27:35 -0500, a écrit :
It seems to happen randomly when executing the 'rpm' or 'yum'
commands. It happens on centos 5, 5.1, and 5.2 machines while using
the xen kernel and on 3 of my completely different servers. When it
does happen, all the strace outputs seem to be the same, encountering
the SIGFPE after the second gettimeofday. What should I provide to
help track this issue down?

Well, I had a look at the rpm code, and it's quite bogus: it uses
gettimeofday() to measure the time taken by nanosleep(20ms). There is
no way that can reliably work in all environments, virtualized or not,
since the resolution of gettimeofday may be >20ms (posix even says it is
unspecified). The attached patch should fix that, but I guess it'll be
hard to get it applied to all rpm-based distributions :/

Samuel
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