Editing repository .md file floods renderer process

Type: Bug

Seemed to have started just this week: If I'm typing and modifying an .md file that's committed to a repository, the renderer process will spin up its thread and my machine's fans. CPU usage hit 5.5% (roughly a full core). This happens with just a few keys, consistently. Doesn't seem to happen with other file types, and doesn't happen if the .md file isn't in the repository. Tested with extensions disabled. No markdown preview visible. Minimap disabled. Viewed with process explorer.

Weird, and highly annoying.

VS Code version: Code 1.138.0 (7debcd0e2acdea1c52de81bf9ee1620444407dda, 2026-09-15T07:24:32Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|AMD Ryzen 9 7900 12-Core Processor (24 x 3693)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x1002, DEVICE=0x73ff [AMD Radeon RX 6600], DRIVER_VENDOR=AMD, DRIVER_VERSION=32.0.21043.1005 *ACTIVE*
GPU1: VENDOR= 0x1002, DEVICE=0x164e [AMD Radeon(TM) Graphics], DRIVER_VERSION=32.0.21043.1005
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.9278
Machine model name:
Machine model version:
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: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|63.09GB (47.57GB free)|
|Process Argv|--disable-extensions . --crash-reporter-id 8f2ffd88-f5f1-4fae-9301-48b73df06fc0|
|Screen Reader|no|
|VM|0%|
Extensions disabled
A/B Experiments

```
vsliv368cf:30146710
pythonvspyt551cf:31249601
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
82j33506:31327384
envsactivate1:31551504
cloudbuttont:31379625
3efgi100_wstrepl:31403338
bj468946:31457056
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
c3h7c220:31478652
cp_cls_t_1081:31454832
conptydll_true:31498968
e9c30283:31461165
46204921:31447328
capico_axe_098a3278:31582664
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
23c7c724:31520045
ddid_t:31478206
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
gf14b233:31526830
ahp-both-windows:31556933
ihg5j128:31534457
7g2b5551:31542111
nes-ex-cf-euporie-03:31542868
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
maidictation:31565333
0c1h4866:31566224
session-mark-done:31558131
5b8j3302:31564601
autotiers:31584978
mangle-name-control:31572633
signed-out-control:31584138
intellij_nes_preview_t:31580086
multiv2:31574985
2bfb8b39:31585911
unread:31581112
aw-autom-on:31583758
revealsession_control_7ed7e840:31582193
4ab0b639:31584543
codex-agent-host-stable-control:31585316
66c8a39e-e7a5-4b4c-a3c0-41b161c795c4:31586113
permission_prompt_treatment:1332566
ccr_pr_nudge_adoption:1319471
vsc_wsm_c:1340633
cfee5631:1379228
3aced641:1389836
sem_714gi995:1401462

```