New version of Jupyter notebook is extremely slow

Issue Type: Performance Issue

Recently I updated my jupyter notebook in vscode. I’'m glad that many jupyter features are supported in the nee version. However, I found that the execution of jupyter cells become extremely slow. I wrote some code to record the real execution time of my code. It turns out that the real execution time is not so long. But the time shown in the left-bottom cornor of jupyter cells are much longer than the real execution time. Sometime the reaction time is also exetremely slow, for example I pressed ‘Shift+Enter’ but it takes even one minute to start to execute the cell.

VS Code version: Code 1.59.0 (379476f0e13988d90fab105c5c19e7abc8b1dea8, 2021-08-04T23:13:12.822Z) OS version: Windows_NT x64 10.0.19043 Restricted Mode: No Remote OS version: Linux x64 4.4.0-19041-Microsoft

System Info

Item	Value
CPUs	Intel® Core™ i5-6500 CPU @ 3.20GHz (4 x 3192)
GPU Status	2d_canvas: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: enabled_on video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	63.89GB (52.36GB free)
Process Argv	–folder-uri=vscode-remote://wsl+Ubuntu/mnt/c/kfm/Computation --remote=wsl+Ubuntu --crash-reporter-id 608d2da6-c9b1-441b-a70e-018fd8f4ecf8
Screen Reader	no
VM	0%

Item	Value
Remote	WSL: Ubuntu
OS	Linux x64 4.4.0-19041-Microsoft
CPUs	Intel® Core™ i5-6500 CPU @ 3.20GHz (4 x 3192)
Memory (System)	63.89GB (52.36GB free)
VM	0%

Process Info

CPU %	Mem MB	   PID	Process
    0	   111	  4500	code main
    0	   100	  4528	   window (undefined)
    0	    86	  5460	   window (Issue Reporter)
    0	    27	  6552	   crashpad-handler
    0	   114	  7628	   window (undefined)
    0	   303	  9812	   gpu-process
    0	    90	 11504	   shared-process
    0	    66	 10288	     ptyHost
    0	    41	 11572	   utility
    1	   862	 13980	   window (● pprVO.ipynb - Computation [WSL: Ubuntu] - Visual Studio Code)
    0	   123	  8300	     extensionHost
    0	    65	  8232	       electron_node wslDaemon.js 
    0	     8	  1632	         C:\WINDOWS\System32\wsl.exe -d Ubuntu sh -c '"$VSCODE_WSL_EXT_LOCATION/scripts/wslServer.sh" 379476f0e13988d90fab105c5c19e7abc8b1dea8 stable .vscode-server 0  '
    0	    12	  5740	           console-window-host (Windows internal process)
    0	     8	 10688	           C:\WINDOWS\system32\lxss\wslhost.exe {a54a2b26-e418-4524-99ca-55fd4d1733f8} 508 516 520
    0	    14	 10432	             console-window-host (Windows internal process)

Remote: WSL: Ubuntu
CPU %	Mem MB	   PID	Process
    1	     0	   129	remote agent
    0	     0	   140	   ptyHost
    0	     0	   197	     /bin/bash
   19	     0	   166	   watcherService
   23	     0	   185	   extensionHost
    0	     0	   339	     /home/kfm/.vscode-server/bin/379476f0e13988d90fab105c5c19e7abc8b1dea8/node /home/kfm/.vscode-server/extensions/ms-python.vscode-pylance-2021.8.0/dist/server.bundle.js --cancellationReceive=file:d3dd6329a670fe53ae94e44c4b717a4a3d908af328 --node-ipc --clientProcessId=185
    0	     0	   411	     /home/kfm/Programs/anaconda3/bin/python -m vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v
    0	     0	   412	     /home/kfm/Programs/anaconda3/bin/python -m vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v
    0	     0	   413	     /home/kfm/Programs/anaconda3/bin/python -m vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v
    0	     0	   424	     /home/kfm/Programs/anaconda3/bin/python -m vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.kernel_launcher_daemon -v
    0	     0	   426	       electron_node oMNPM.js 
    0	     0	   819	   /bin/sh -c /usr/bin/ps -ax -o pid=,ppid=,pcpu=,pmem=,command=
    0	     0	   820	     /usr/bin/ps -ax -o pid=,ppid=,pcpu=,pmem=,command=

Workspace Info

|  Remote: WSL: Ubuntu|    Folder (Computation): 10449 files|      File types: 1(1819) xsf(788) log(481) psf(368) cube(365) nc(364)
|                  fdf(322) xml(276) ion(273) xyz(210)
|      Conf files: settings.json(2);

Extensions (16)

Extension	Author (truncated)	Version
remote-ssh	ms-	0.65.7
remote-ssh-edit	ms-	0.65.7
remote-wsl	ms-	0.58.2
material-icon-theme	PKi	4.9.0
ayu	tea	0.20.1
vscode-icons	vsc	11.6.0
json-parse-validator	Adr	1.1.2
vscode-ipython	Che	0.6.2
nbpreviewer	jit	1.2.2
linter-gfortran	krv	2.3.0
MagicPython	mag	1.1.0
python	ms-	2021.8.1105858891
vscode-pylance	ms-	2021.8.0
jupyter	ms-	2021.8.1195043623
cpptools	ms-	1.5.1
markdown-all-in-one	yzh	3.4.0

(3 theme extensions excluded)

A/B Experiments

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vsreu685:30147344
python383:30185418
vspyt653:30270858
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pythonptprofiler:30281270
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vstes263:30335439
pythondataviewer:30285071
pythonvsuse255:30340121
vscod805cf:30301675
pythonvspyt200:30340761
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binariesv615:30325510
pythonvssor306:30344512
bridge0708:30335490
vstre464cf:30350173

[kongfanmiao]

Ok, so the delay is not in running a cell, but in starting the kernel. I.e. once you have run the first cell, running subsequent cells, such as 1+1 again doesn’t take 30seconds. is that correct?

Not really. Actually the case is the opposite. The first time I run “1+1” was very fast. The second time it took 30 seconds.

[taigaoma1997]

I also have the same issue, anyone knows how to fix this?

My jupyter is fine when running the first time. But after running several cells, it gets extremely slow. When I press “run”, it didn’t start to run until 10 or 20 seconds later. I also couldn’t interrupt the kernel, since interrupt/restart also gets very slow.

Another situation I noticed is that, if in my code cell, I accidentally write some typo, e.g., I used a variable/function that was never defined before, it gets extremely slow, and after a long time it will tell me that this variable/function is not defined; or I accidentally missed a “:” in the while loop, it will also take a long time to find this typo.

OS: Ubuntu 20.04.3 LTS (Focal Fossa) Python: 3.8.12 Python Extension: v2021.11.1422169775 Jupyter Extension: v2021.10.1001414422 VS code: 1.62.1

@DonJayamanne