Bug 453493

Summary:	Freezes while loading php files from nfs mounted volume
Product:	[Applications] kate	Reporter:	Mark Stanton <mark>
Component:	application	Assignee:	KWrite Developers <kwrite-bugs-null>
Status:	RESOLVED FIXED
Severity:	major	CC:	christoph
Priority:	NOR
Version First Reported In:	21.12.2
Target Milestone:	---
Platform:	Fedora RPMs
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Mark Stanton 2022-05-07 10:44:33 UTC

Loading a php file from an nfs mounted volume results in a long delay.  During the delay there is a lot of network activity.  On a 10k file the delay is something like a minute (I have a very fast machine, the nfs volume is mounted from a machine less than 10cm away over a 1Gb/s network link).  The same file loaded from a local directory shows no noticeable delay.

There is no difference whether the file is loaded from a file manager (I use Krusader), ie without Kate already open, or from Kate's own menu (ie already open).

This has only started happening within the last couple of weeks (I don't remember exactly when).

STEPS TO REPRODUCE
1. Load a php file from an nfs mounted volume.

OBSERVED RESULT

The file loads, but the Kate window (and any other Kate window open at the same time) is totally unresponsive for a noticeable (possibly long) period of time.

EXPECTED RESULT

Kate can be used as normal immediately.

SOFTWARE/OS VERSIONS
Linux Version: Fedora 35
KDE Plasma Version: 5.24.4
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION

Kernel Version: 5.17.5-200.fc35.x86_64 (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 3800X 8-Core Processor
Memory: 31.3 GiB of RAM

Comment 1 Christoph Cullmann 2022-05-07 17:29:06 UTC

Hi, I use Kate daily even with NFS mounted home directories, I have never had such a lag.

I strongly doubt this is a issue in Kate, for local files (e.g. all mounted stuff) we just do plain QFile open and read/write (aka local file handling).

During load we don't do anything else, perhaps just walking some directories upwards to detect config files.

As a try, do other applications behave the same?

e.g. what does happen for KWrite?

And what does happen for a completely different one like gEdit or Atom?

Comment 2 Mark Stanton 2022-05-08 18:13:25 UTC

Hi @Christoph,

I agree, it seemed highly unlikely.  But I did check with various files, and checked those files with other editors (my working fallback was "Text Editor" from the context menu, looks Gnome-ish), and the problem was very specific.

However, since yesterday, these very specific instances do not cause the problem.
What's changed?  My weekly update from Fedora repos. There were a whole load of updates, including the kernel, so I don't know what, if anything made the difference.

However, tl:dr is, I can no longer reproduce this problem.  I'll close it.

Comment 3 Christoph Cullmann 2022-05-08 18:16:44 UTC

Ok, given NFS is a fragile thingy, any kernel update can have interesting effects, at least that is my experience from work.