Slow Java initialization during startup

I have Matlab R2023a installed on an up-to-date Arch Linux system. Installation didn't have any issues but it takes several minutes for Matlab to start. The splash screen appears right away but then it is stuck there for several minutes before the main interface appears.

Staring with the -timing flag points to PostVMInit and InitDesktop, whatever those are.

MATLAB Startup Performance Metrics (In Seconds)

total   item     gap      description
=========================================================
0.18   0.18    0.00   MATLAB script                           
0.25   0.07   -0.00   main                                    
0.27   0.02    0.00   Session Initialize                      
0.74   0.00    0.47     Toolbox cache load Start              
0.74   0.18    0.29   Session Initialize                      
0.90   0.04    0.87   LM Startup                              
0.92   0.18    0.74   cachepath                               
0.93   0.02    0.00   splash                                  
1.13   0.12    0.08     Constant Initialization               
1.15   0.23    0.00   Engine Startup                          
1.22   0.07    0.00      InitSunVM                            
242.13  240.89    0.03      PostVMInit                           
242.13  240.98    0.00     mljInit                               
242.39   0.26    0.00     StartDesktop                          
242.39  241.24    0.00   Java initialization                     
242.39   0.00    0.00   psParser                                
242.42   0.00    0.03   Toolbox cache join                      
242.68   0.17    0.08   matlabpath                              
242.88   0.05    0.16   matlabrc                                
363.68  121.29   242.39     Init Desktop                          
363.74  121.35   242.39   Ready                                   
=========================================================
Items shown account for 100.0% of total startup time

Running bare with matlab -nojvm starts quickly.

< M A T L A B (R) >
Copyright 1984-2023 The MathWorks, Inc.
R2023a Update 1 (9.14.0.2239454) 64-bit (glnxa64)
March 30, 2023

Warning: X does not support locale en_US.UTF-8

For online documentation, see https://www.mathworks.com/support
For product information, visit www.mathworks.com.

>>     MATLAB Startup Performance Metrics (In Seconds)

total   item     gap      description
=========================================================
0.20   0.20    0.00   MATLAB script
0.26   0.07    0.00   main
0.28   0.01    0.00   Session Initialize
0.69   0.00    0.41     Toolbox cache load Start
0.69   0.14    0.27   Session Initialize
0.85   0.04    0.81   LM Startup
0.85   0.00    0.00   splash
0.85   0.16    0.69   cachepath
1.02   0.10    0.08     Constant Initialization
1.04   0.20    0.00   Engine Startup
1.04   0.00    0.00   Java initialization
1.05   0.00    0.00   psParser
1.07   0.00    0.02   Toolbox cache join
1.26   0.15    0.04   matlabpath
1.41   0.03    0.12   matlabrc
=========================================================
Items shown account for 70.6% of total startup time

Answer 1

[Vinayak]

A few methods that could be implemented to curb this would be

1. Increasing Java Memory heap space, You can increase the Java heap space by editing the "javaclasspath.txt" file in the MATLAB preferences directory. This file is used to configure the Java classpath and other Java related settings. You can add the following line to set the Java heap size:

-Xmx2048M

1. Holy Trinity, Holy trinity refers to a series of steps taken to rehash the toolbox and matlab paths

rehash
rehash toolbox
rehash toolboxcache

[Tyler]

The file javaclasspath.txt didn't exist so I created it at ~/.matlab/R2023a/ and added the line you gave me.

It no longer gets stuck at Init Desktop but PostVMInit is stil slow. After the main gui appears, it also takes another two minutes of Initializing... which didn't happen before. So I'm still waiting about the same amount of time before the software is usable.

total   item     gap      description
=========================================================
0.17   0.17    0.00   MATLAB script
0.24   0.07    0.00   main
0.25   0.01    0.00   Session Initialize
0.66   0.00    0.41     Toolbox cache load Start
0.66   0.15    0.26   Session Initialize
0.78   0.12    0.66   cachepath
0.82   0.03    0.79   LM Startup
0.83   0.01    0.00   splash
0.99   0.10    0.06     Constant Initialization
1.01   0.18    0.00   Engine Startup
1.07   0.06    0.00      InitSunVM
121.75  120.66    0.02      PostVMInit
121.75  120.74    0.00     mljInit
121.96   0.21    0.00     StartDesktop
121.96  120.95    0.00   Java initialization
121.96   0.00    0.00   psParser
121.99   0.00    0.02   Toolbox cache join
122.26   0.21    0.07   matlabpath
122.46   0.04    0.15   matlabrc
123.41   1.45   121.96     Init Desktop
123.47   1.51   121.96   Ready
=========================================================
Items shown account for 100.0% of total startup time

FYI, I see the following errors reported at the end of Initializing... Not sure if that is relevant.

com.jogamp.opengl.GLException: X11GLXDrawableFactory - Could not initialize shared resources for X11GraphicsDevice[type .x11, connection :0, unitID 0, handle 0x0, owner false, ResourceToolkitLock[obj 0x4338e6d3, isOwner false, <1cc85f20, 79a04148>[count 0, qsz 0, owner <NULL>]]]
	at jogamp.opengl.x11.glx.X11GLXDrawableFactory$SharedResourceImplementation.createSharedResource(X11GLXDrawableFactory.java:326)
	at jogamp.opengl.SharedResourceRunner.run(SharedResourceRunner.java:297)
	at java.lang.Thread.run(Thread.java:750)
Caused by: java.lang.NullPointerException
	at jogamp.opengl.GLContextImpl.makeCurrent(GLContextImpl.java:688)
	at jogamp.opengl.GLContextImpl.makeCurrent(GLContextImpl.java:580)
	at jogamp.opengl.x11.glx.X11GLXDrawableFactory$SharedResourceImplementation.createSharedResource(X11GLXDrawableFactory.java:297)
	... 2 more

[Vinayak]

Hi Tyler,

1. You could try removing some toolboxes or addons you dont use frequently via the add on manager and check to see if it improves the startup time.
2. There is a possibility that you have some custom startup files in 'startup.m'. You can try to run matlab without these to see if it improves startup time. This can be done by using -nosplash -nojvm -nodesktop -nodisplay' flags in the command line while starting MATLAB.
3. Increasing the JVM Memory, I had already mentioned this in the last comment and you had also ascertained that you ran the command that I provided. Just to be sure you could go to the "Advanced" tab in the "Preferences" dialog box and click on "Java Heap Memory". and confirm the "Initial Heap Size" and "Maximum Heap Size" fields.
4. If nothing works, maybe upgrading to the latest version or a last resort could be to reinstall MATLAB.

Thanks,

Vinayak

[Tyler]

Is the end, I did a reinstall and now it is starting normal. Thank you.