Re: bigcore.exp on 64-bit systems

[Daniel Jacobowitz <drow at false dot org>]

On Sat, Jan 13, 2007 at 04:09:37PM +0200, Eli Zaretskii wrote:
> I'm trying to run the testsuite on a 64-bit machine that identifies
> itself thusly:
> 
>     Linux fencepost 2.6.16.29-xen #1 SMP Wed Dec 6 07:32:36 EST 2006 x86_64 GNU/Linux

Hi fencepost! :-)

> On this machine, bigcore.exp is a pest: it runs for a very long time,
> produces a humongous core file (so large that I expect the sysadmins
> to send me angry emails), and eventually fails (or so it seems).
> Here's what gdb.sum says about it:

The core file is probably not that large.  Could you check with 'du'?
As Mark said, it's supposed to be a sparse file - in case you're not
familiar with them, that means that ls -l will show something huge
but du will show something quite small.  Most of the all-zero blocks
will not have any on-disk representation.

Of course, how efficient large sparse files are depends on the
filesystem.  I've never used xfs; it might be an xfs-specific
problem.  Also, I know that there was a problem in the 2.6.1x series
somewhere (bad choice of locking) that led to this test taking a
really long time - but I don't know what version was affected.

It's not necessarily a problem on a 64-bit system; I run it on
one normally.  It takes twenty or thirty seconds to dump core,
which is much longer than it ought to take, but much shorter
than it's taking for you.

I'm not sure what to suggest :-(  If it is a sufficient nuisance,
perhaps we should add a way for you to disable the test.

-- 
Daniel Jacobowitz
CodeSourcery