[CURRENT]: weird memory/linker problem?

[Allan Jude]

On 2014-06-22 10:56, O. Hartmann wrote:
> 
> Hello.
> 
> I face a strange problem on a set of CURRENT driven boxes. The systems in question are
> all the same version of CURRENT (more or less, a week or so discrepancy).
> 
> The boxes affected have 8 GB of RAM and are old-style Core2Duo systems.
> 
> The phenomenon:
> 
> Starting up the box shows the operating system working. But sometimes it is impossible to
> start certain applications, like Firefox - they segfault. More disturbing is the fail of
> the linker when building world. Sometimes I get strange messages like
> 
> relocation truncated to fit: R_X86_64_PC32 against symbol `__error' defined in .text
> 
> when compiling/linking. The funny thing is: rebooting the box and doing exactly the same
> very often leaves the system then operable - starting applications works, compiling works!
> 
> First I thought this could be a indication of a dying system and so I checked the memory
> for two days non-stop without any indication of anything wrong. The boxes do not have ECC
> RAM - it's Intel.
> 
> I see this problem on two C2D based boxes relatively often (one E8400 two core, another
> Q6600 quadcore, both systems have 8 GB RAM). This phenomenon also occured two or three
> months ago on another machine with 32 GB RAM and a Core-i7 3930K, but it went away (it was
> the very same error as shown above).
> 
> Another system, a i3-3220 with 16 GB RAM never showed the problem although that system
> build world also on a regular basis very frequent as the C2D systems do.
> 
> Well, I feel a bit confused. On the first view, the problem looks weird and it indicates
> a kind of memory problem - but testing the memory didn't show anything wrong. 
> 
> Today "windowmaker" stopped starting due to a malformed command in one of windowmaker's
> library. I did reboot the box and everything was all right. Then, also today, I tried
> compiling world and I got a weird error message about a misspelled "Int__xxx", I can not
> remember exactly the text, I rebooted and everything was all right again.
> 
> Those errors are frequent on 8GB, C2D based systems and at the moment not present any
> more on more modern systems with more memory as described above. This could be a
> coincidence, but it is strange anyway.
> 
> I do not exclude dying hardware, but I'd like to ask whether there is something strange
> going on with FreeBSD's memory management at the moment and whether those problems could
> also be triggered by some nasty bug? I never see a crash (which would also indicated
> faulty hardware), I mostly realise those strange behaviour either after a fresh boot or
> after I ran some memory disk i/o intensive jobs, like updating the ports tree.
> 
> By the way, FreeBSD CURRENT suffer from a tremendous performance cut these days when
> compiling world and updating the ports tree and running portmaster. On one box, on which
> ports reside on a UFS partion, it takes more than 8 minutes to pass the portmaster -da,
> which is quick when not compiling world. On another system on which /usr/ports is
> residing on ZFS (the box has 16GB RAM!), it takes sometimes 30(!) minutes to perform a
> "svn update" while compiling world (that is the i3-3220 with 16 GB RAM system), it takes
> 6 - 15 minutes when the box is relaxed and updating the ports tree the first time (every
> subsequent update is much faster).
> 
> Well, I know these reports of mine are a bit weird since I have no exact log of the
> problems, but I think if there is an issue not with the hardware, I report those in.
> 
> Regards,
> 
> oh
> 

In order to get a better benchmark for 'svn update' on the ports tree

if you 'zfs unmount pool/usr/ports' it will flush all ARC entries for
that dataset, then 'zfs mount pool/usr/ports' and run the test again.
This should give you more reproducible results

-- 
Allan Jude

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