Samuel,
On 01/01/2026 14:03, Samuel Thibault wrote:
Michael Kelly, le jeu. 01 janv. 2026 13:38:10 +0000, a ecrit:
Are you uninstalling/installing the dependencies each time?
Yes, it's a fairly minimal base.tgz. The qtcreator build installs 340
packages. I'm not saving the pbuilder chroot so it installs the same way
for each build.
I have run with and without mach-defpager but there is evidence to
suggest that on my machine swapping is required by the build process with
the message 'vm_page warning: unable to recycle any page' being output.
That message does not mean that swapping is required, on the contrary it
means that paging out didn't manage to free memory.
My reasoning assumes that external pages can almost all be paged out as
required. The appearance of that message therefore implies to me that
external pageout was not sufficient and internal pageout would have been
necessary to free memory.
I have seen stress_ng tests report bit errors which potentially could
be from the same cause. I've only seen those errors on 64 bit Hurd.
That would still be worth investigating.
It would indeed but unfortunately it's a very rare occurrence too. I've
only seen a handful of such reports in months.
4) Are there any packages other than qtcreator that show this issue
regularly?
Yes, various packages do it.
For instance:
sysprof:
https://buildd.debian.org/status/fetch.php?pkg=sysprof&arch=hurd-i386&ver=49.0-4&stamp=1766538245&raw=0
but I guess it's actually spirv-llvm-translator-20 that got built just
before that triggered the issue, without symptoms in its own build:
https://buildd.debian.org/status/fetch.php?pkg=spirv-llvm-translator-20&arch=hurd-i386&ver=20.1.9-1&stamp=1766534212&raw=0
survivor:
https://buildd.debian.org/status/fetch.php?pkg=survivor&arch=hurd-amd64&ver=1.0.7-6&stamp=1766520613&raw=
but again, I guess it's actually rustc that triggered the issue:
I think perhaps I'll set up a cycle of continuous build across this set
of packages including qtcreator.
https://buildd.debian.org/status/fetch.php?pkg=rustc&arch=hurd-amd64&ver=1.91.1%2Bdfsg1-1~exp3&stamp=1766519978&raw=0
5) Finally, what is the likelihood of a build failure for qtcreator (ie. 1
in N builds approximately) ?
It's hard to say. The 4 buildds keep building packages all day long, and
I notice such "stray" errors on one of them like every one day or two.
That's possibly as rare as the stress-ng bit errors then given that my
machine is almost certainly slower than those supporting the buildds.
6) Is eatmydata being used for the build?
Ah, yes.
I've been using that too.
On 01/01/2026 14:19, Samuel Thibault wrote:
Note: since your latest changes have made active external page page-out
way less frequent, it may have made the issue way less frequent. You may
have to revert that to trigger the issue more often.
I'm using gnumach 2:1.8+git20251228-1 which has some of the recent
changes but not the change to the actual eviction policy. I believe this
version should operate very similarly to any from the the last 6 months
or so.
Cheers,
Mike.
