perf: modified takes a long time when refreshing

[Kaiser-Yang]

Description

When a folder with many files is expanded and the modified feature is on, editing in buffers will suffer a significant lag.

Log files:

https://github.com/Kaiser-Yang/image-hosting-site/blob/main/nvim-tree.log

I've found that this is caused by:

nvim-tree.lua/lua/nvim-tree/explorer/init.lua

Lines 185 to 193 in c988e28

	vim.api.nvim_create_autocmd({ "BufModifiedSet", "BufWritePost" }, {
	group = self.augroup_id,
	callback = function()
	utils.debounce("Buf:modified_" .. self.uid_explorer, self.opts.view.debounce_delay, function()
	buffers.reload_modified()
	self:reload_explorer()
	end)
	end,
	})

The refresh_nodes takes a long time in sync mode:

nvim-tree.lua/lua/nvim-tree/explorer/init.lua

Lines 471 to 484 in c988e28

	function Explorer:refresh_nodes(projects)
	Iterator.builder({ self })
	:applier(function(n)
	local dir = n:as(DirectoryNode)
	if dir then
	local toplevel = git.get_toplevel(dir.cwd or dir.link_to or dir.absolute_path)
	self:reload(dir, projects[toplevel] or {})
	end
	end)
	:recursor(function(n)
	return n.group_next and { n.group_next } or (n.open and n.nodes)
	end)
	:iterate()
	end

But I think iterating about 20000 nodes should not be so slow.

The workaround for this problem is just to disable the modified feature.

Neovim version

NVIM v0.11.4
Build type: RelWithDebInfo
LuaJIT 2.1.1753364724
Run "nvim -V1 -v" for more info

Operating system and version

Linux archlinux 6.16.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 02 Oct 2025 19:26:36 +0000 x86_64 GNU/Linux

Windows variant

No response

nvim-tree version

e11ce83

Clean room replication

vim.g.loaded_netrw = 1
vim.g.loaded_netrwPlugin = 1

vim.cmd([[set runtimepath=$VIMRUNTIME]])
vim.cmd([[set packpath=/tmp/nvt-min/site]])
local package_root = '/tmp/nvt-min/site/pack'
local install_path = package_root .. '/packer/start/packer.nvim'
local function load_plugins()
  require('packer').startup({
    {
      'wbthomason/packer.nvim',
      'nvim-tree/nvim-tree.lua',
      'nvim-tree/nvim-web-devicons',
      -- ADD PLUGINS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
    },
    config = {
      package_root = package_root,
      compile_path = install_path .. '/plugin/packer_compiled.lua',
      display = { non_interactive = true },
    },
  })
end
if vim.fn.isdirectory(install_path) == 0 then
  print('Installing nvim-tree and dependencies.')
  vim.fn.system({ 'git', 'clone', '--depth=1', 'https://github.com/wbthomason/packer.nvim', install_path })
end
load_plugins()
require('packer').sync()
vim.cmd([[autocmd User PackerComplete ++once echo "Ready!" | lua setup()]])
vim.opt.termguicolors = true
vim.opt.cursorline = true

-- MODIFY NVIM-TREE SETTINGS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
_G.setup = function()
  require('nvim-tree').setup({
    -- Enable modified
    modified = { enable = true },
  })
end

Steps to reproduce

Steps to repro:

1. Use nvim -u repro.lua to start up nvim in a directories with about 20,000 files
2. Open nvim tree, and expand the directory with many files:

3. Open a file and start to edit it. (Or a floating window like telescope pickers)

Expected behavior

No response

Actual behavior

No response

[alex-courtis]

Thanks for the detailed report. Investigation notes:

I'm not able to reproduce (<1 ms) under the following test:

#!/usr/bin/env sh

rm -rf dir*

for i in $(seq 1 1 100); do
	mkdir -p "dir-$i"
	for j in $(seq 1 1 100); do
		touch "dir-$i/file-$j"
	done
done

It looks like we have the file available from the modified events:

        log.line("dev", "mod data=%s", vim.inspect(data))

[2026-03-02 14:22:00] [dev] mod data={
  buf = 1,
  event = "BufWritePost",
  file = "dir-23/file-10",
  group = 22,
  id = 36,
  match = "/home/alex/src/nvim-tree/r/3284/test/dir-23/file-10"
}
[2026-03-02 14:22:00] [dev] mod data={
  buf = 1,
  event = "BufModifiedSet",
  file = "/home/alex/src/nvim-tree/r/3284/test/dir-23/file-10",
  group = 22,
  id = 36,
  match = "/home/alex/src/nvim-tree/r/3284/test/dir-23/file-10"
}

Reload modified does only parse the actually modified buffers:

log.line("dev", "reload_modified buf.name %s", vim.inspect(buf.name))

[2026-03-02 14:27:07] [dev] mod data={
  buf = 7,
  event = "BufModifiedSet",
  file = "/home/alex/src/nvim-tree/r/3284/test/dir-10/file-18",
  group = 22,
  id = 36,
  match = "/home/alex/src/nvim-tree/r/3284/test/dir-10/file-18"
}
[2026-03-02 14:27:07] [dev] reload_modified buf.name "/home/alex/src/nvim-tree/r/3284/test/dir-13/file-100"
[2026-03-02 14:27:07] [dev] reload_modified buf.name "/home/alex/src/nvim-tree/r/3284/test/dir-13/file-24"
[2026-03-02 14:27:07] [dev] reload_modified buf.name "/home/alex/src/nvim-tree/r/3284/test/dir-10/file-10"
[2026-03-02 14:27:07] [dev] reload_modified buf.name "/home/alex/src/nvim-tree/r/3284/test/dir-10/file-15"
[2026-03-02 14:27:07] [dev] reload_modified buf.name "/home/alex/src/nvim-tree/r/3284/test/dir-10/file-18"

We could potentially replace the reload with a redraw, however I have a suspicion that the reload was intentional. Git / PR history will need to be examined.

[alex-courtis]

In the logs there are a lot of git, explorer and watcher events in there that I'm not seeing:

: ; cat nvim-tree.log | grep -E "^\[" | sed -E 's/\] \[(.*)\].*/ \1/g' | sort | uniq -c
      1 [2026-03-01 17:03:13 diagnostics
     12 [2026-03-01 17:03:13 git
     48 [2026-03-01 17:03:13 profile
   1354 [2026-03-01 17:03:13 watcher
      2 [2026-03-01 17:03:14 profile
     83 [2026-03-01 17:03:15 git
    319 [2026-03-01 17:03:15 profile
    137 [2026-03-01 17:03:16 git
    548 [2026-03-01 17:03:16 profile
    121 [2026-03-01 17:03:17 git
    486 [2026-03-01 17:03:17 profile
     99 [2026-03-01 17:03:18 git
    394 [2026-03-01 17:03:18 profile
      9 [2026-03-01 17:03:19 git
     43 [2026-03-01 17:03:19 profile
      4 [2026-03-01 17:03:20 git
    467 [2026-03-01 17:03:20 profile
    433 [2026-03-01 17:03:21 profile

Please supply a tar/zip of a directory that we can use to reproduce the problem so that it can be definitively fixed.

[Kaiser-Yang]

Sorry for the missed information: there are about 7000 files untracked in my working directory.

I will upload a tar.gz file, and give a more detailed steps to reproduce:

1. Download the tar.gz files and extract from the file （git-lfs required)
2. Enter the experiment directory
3. Start up nvim with nvim -u repro.lua
4. Open nvim-tree with :NvimTreeOpen
5. Expand the record directory
6. Return to the main window, and use :e LICENSE to edit the LICENSE file

The tar.gz file is in image-hosting-site called e.tar.gz.

Update， all options for nvim-tree:

    view = {
      number = true,
      relativenumber = true,
      preserve_window_proportions = true,
    },
    renderer = {
      group_empty = true,
      indent_markers = { enable = true },
      hidden_display = 'all',
    },
    diagnostics = { enable = true, show_on_dirs = true },
    -- PERF:
    -- See https://github.com/nvim-tree/nvim-tree.lua/issues/3284
    modified = { enable = true },
    filters = {
      git_ignored = true,
      dotfiles = not u.in_config_dir(),
      custom = { '^\\.git$' },
    },
    actions = {
      file_popup = { open_win_config = { border = vim.o.winborder } },
      open_file = {
        window_picker = {
          exclude = {
            filetype = {
              'notify',
              'packer',
              'qf',
              'diff',
              'fugitive',
              'fugitiveblame',
              'smear-cursor',
              'snacks_notif',
              'noice',
            },
            buftype = { 'terminal', 'quickfix', 'prompt' },
          },
        },
      },
    },

[alex-courtis]

Reproduced:

: ; cat $XDG_STATE_HOME/nvim/nvim-tree.log | grep -E "^\[" | sed -E 's/\] \[(.*)\].*/ \1/g' | sort | uniq -c
      1 [2026-03-03 09:10:00 diagnostics
     13 [2026-03-03 09:10:02 git
     48 [2026-03-03 09:10:02 profile
   1354 [2026-03-03 09:10:02 watcher
      2 [2026-03-03 09:10:13 profile
    213 [2026-03-03 09:10:35 git
    839 [2026-03-03 09:10:35 profile
    236 [2026-03-03 09:10:36 git
    951 [2026-03-03 09:10:36 profile
      4 [2026-03-03 09:10:48 profile

[alex-courtis]

Fix branch pushed #3285

I'd be most grateful if you thoroughly tested a fix branch

cd /path/to/nvim-tree.lua
git pull
git checkout 3284

When you're finished testing:

git checkout master

[Kaiser-Yang]

I've tested it. Fixed.