Re: I/O lockup

[Samuel Thibault]

Joshua Branson, le jeu. 31 oct. 2024 11:08:13 -0400, a ecrit:
> Samuel Thibault <samuel.thibault@gnu.org> writes:
> > That being said, we definitely need to fix this, it's also making
> > buildds crawl to a halt while building some large packages.
> 
> How do go about fixing this?

As always: essentially investigate. I.e. check in the stuck case what
exactly is stuck, what values look bogus, etc.

> I'm assuming the problem you are trying to fix is what's described in
> this email:  
> 
> https://lists.gnu.org/archive/html/bug-hurd/2009-07/msg00084.html

Not really. What I have observed is not a problem of resources that
are not properly attributed, but rather that the page cache is getting
large and not pushed to disk fast enough, or not getting shrinked fast
enough when memory is getting scarce, etc. Again, investigation needed
to *observe* what is happening rather than doing guesswork at might be
wrong (which can bring thousands of potential hypotheses)

Samuel