Bug 334325

Summary: baloo_file_extractor slows down whole system while extracting big tar file
Product: [Unmaintained] Baloo Reporter: Julian Schmidt <julian>
Component: GeneralAssignee: Vishesh Handa <me>
Status: RESOLVED FIXED    
Severity: normal    
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Kubuntu   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Julian Schmidt 2014-05-04 12:42:19 UTC 
While extracting a huge tar file, baloo_file_extractor made my system so slow it was unusable. Adding my home directory (where I was extracting the files to) to the desktop search blacklist solved the issue immediately. 


Reproducible: Always

Steps to Reproduce:
1. start extracting a big tarfile (several GB)
2. wait
3. system gets slower and slower
Actual Results:  
I just extracted a really big tar file (old backup, several GB) on my drive.
The system kept getting slower and slower, up to a point where e.g. opening a new terminal/konsole tab took about 30 seconds. The system was nearly unusabe.

iotop showed me baloo_file_extractor and baloo_file_cleaner both hogging 99% IO load.
A balooshow indicated that it was indexing the files I was currently extracting.

Adding my home directory (where I was extracting the files to) to the desktop search blacklist solved the issue immediately. I could use the system again while the tar file was still extracting.

Expected Results:  
indexing is fine, but it should not hog all available disk ressources to do so, effectively slowing down all other applications while indexing.

baloo_file_cleaner was still running with high IO load, but the KDE user interface was very responsive again.

I noticed strange slowdowns of the system before while I was copying big amounts of files around, but thought it was due to old hardware.

I just updated to a new i5 quadcore with 8gb of ram yesterday and the problem of KDE getting sluggish while moving/extracting big amounts of files remained.

I just found out baloo seems to be responsible.
Comment 1 Vishesh Handa 2014-05-12 10:37:21 UTC 
What kind of files were in the tarball?
Comment 2 Julian Schmidt 2014-05-12 10:41:46 UTC 
it was a backup of an old home folder.
while I noticed it was baloo slowing down the system an I looked via balooshow it was extracting some pdf files. But it was slow before for a long time since I started the extraction.

I also noticed the slowdown while just copying large amounts of random files from an external HDD to my home folder.

since I excluded my home folder from the desktop search KDE is running like a rocket again and I had no sluggy UI ever since.
Comment 3 Vishesh Handa 2014-10-17 11:17:35 UTC 
The default IO scheduler in Kubuntu is deadline, which isn't great from keeping the system very responsive. Kubuntu developers have changed it for 14.10. This should make your system more responsible.

You can change it locally by running the following command -
$ echo "cfq" > /sys/block/{DEVICE-NAME}/queue/scheduler

Change ${DEVICE-NAME} to sda or whatever your disk is.

I'm marking this bug as FIXED. If it's still a problem after changing the io scheduler, then please re-open this bug.