Bug#907057: neverball: Constant fsync calls seriously degrade performance

[Uoti Urpala]

On Mon, 2018-08-27 at 23:13 +0200, Markus Koschany wrote:
> Am 27.08.2018 um 03:36 schrieb Uoti Urpala:
> > Neverball is broken so at least a bug blocked by a physfs bug would be
> > appropriate in any case, and I assume that the easiest way to fix the
> > problem would be to change the Neverball package to stop using
> > libphysfs.
> 
> I cannot confirm that Neverball is broken. I don't see any performance
> issues on my system which is a X230 Lenovo Laptop, not quite a gaming
> laptop but capable to play the game. However I cannot test whether there
> is a performance degradation on slower non-SSD hard disks. So this may
> or may not an issue for older hard disks. 

If FPS stays sufficiently high that it's not a visible issue, you could
try running the binary under strace for example and verify that there
are lots of fsync calls while playing. (The calls probably aren't good
for the SSD either, even if they don't prevent playing the game.)
strace -e fsync -o /tmp/file neverball

> Not using libphysfs would be a workaround and not a fix. Hence I am

I'm not sure why you're saying this. Given that upstream Neverball has
also stopped defaulting to libphysfs use, it seems like a quite
reasonable solution.

> going to clone and reassign this bug report to libphysfs. Upstream have
> not been released a new version for years. Perhaps I will try a recent
> Git snapshot in the future but this surely must be fixed upstream.
> Please ask the upstream developers of Neverball to investigate this
> issue and release a new version. This is not actionable by Debian itself.

AFAIK the version currently in Debian can be built with libphysfs
disabled too. "Not actionable" seems like an exaggeration, even without
packaging a new non-release version.

I just ran a quick test, and building without libphysfs-dev worked with
"git checkout neverball-1.6.0; make -j 6 ENABLE_FS=stdio".