PR loading takes time and is not optimized for gigantic PR with 1500+ files

[hamza512b]

Type: Bug

Here is an idea how to repoduce this:
Clone VScode repo or simliar.
Create new repo ( empty repo).
Bring changes as PR.
And open the vscode extension tab, than preview the files.
It will take forever.

I am facing this while open sourcing my private project.

I looked at duplicates but they are closed now.

Extension version: 0.156.0
VS Code version: Code 1.128.1 (Universal) (5264f2156cbcd7aea5fd004d29eaa10209155d66, 2026-07-14T07:19:31-07:00)
OS version: Darwin arm64 25.5.0
Modes:

System Info

Item	Value
CPUs	Apple M4 (10 x 2400)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x106b [Google Inc. (Apple)], DEVICE=0x0000 [ANGLE (Apple, ANGLE Metal Renderer: Apple M4, Version 26.5.1 (Build 25F80))], DRIVER_VENDOR=Apple, DRIVER_VERSION=26.5.1 ACTIVE Machine model name: Mac Machine model version: 16.10 direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: enabled_on trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgpu: enabled webnn: disabled_off
Load (avg)	5, 5, 3
Memory (System)	16.00GB (0.11GB free)
Process Argv	./my-project --crash-reporter-id my-telementry-id
Screen Reader	no
VM	0%

A/B Experiments

vsliv368cf:30146710
pythonvspyt551:31249599
binariesv615:30325510
f8hc8238:30694864
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsdeactivate2:31538737
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ddidt:31399633
ec5jj548:31422691
cp_cls_t_966_ss:31526232
8hhj4413:31478653
38bie571_auto:31426784
cp_cls_t_1081:31454832
conptydll_true:31498968
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
idci7584:31464702
e3e4d672:31494082
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
7e187181:31503455
i2gc6536:31499202
52612955:31516516
ghj88844:31499326
23c7c724:31520045
ddid_c:31478207
hmra_i5g22:31518061
ja75b849:31547460
ie3bb177:31543534
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
f9bf7985:31543584
jh5f2457_c:31540921
41836166:31537719
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
gf14b233:31526830
nes-curr-leftover-1500:31538366
h561g132:31533256
sessions_3:31532893
ihg5j128:31534457
jh7i3328:31546038
7g2b5551:31542111
sandbox-ui-on-2:31543161
nes-ex-cf-euporie-03:31542868
nes-nc-lc-nf:31546584

[hamza512b]

I could not reproduce on older version of vscode when I boated up a stale vesrion:

Version: 1.107.0
Commit: 618725e67565b290ba4da6fe2d29f8fa1d4e3622
Date: 2025-12-10T07:43:47.883Z
Electron: 39.2.3
ElectronBuildId: 12895514
Chromium: 142.0.7444.175
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Linux x64 7.1.2-arch3-1

But after I have updated to this version then it runs very slow:

Version: 1.128.1
Commit: 5264f2156cbcd7aea5fd004d29eaa10209155d66
Date: 2026-07-14T07:19:31-07:00
Electron: 42.5.0
ElectronBuildId: 14525058
Chromium: 148.0.7778.271
Node.js: 24.17.0
V8: 14.8.178.33-electron.0
OS: Linux x64 7.1.3-arch1-3

[Jinyi-Liu]

I have encountered this same issue.

[jameswilmiller]

I would love to work on this issue if you are open to community contribution. I could start by doing some tests on a scratch repo I just made with 2000+ files. Before opening any PR's would you like me to report back results here, stating where I believe the main performance issues are coming from?

[hamza512b]

Hello James Miller (@jameswilmiller), In anyway if you would like to have a reproduction. I discovered this issue while working on this pr. Though that example pr is merged now and I am unsure if this play effect.