Rust Analyzer very slow to format in VSCode

Editors and IDEs
1

Rust analyzer is taking several seconds (or longer) to format files. cargo fmt can format the entire project in <50ms, and the Rust extension (RLS) is likewise near-instant

My current vscode settings in their entirety in case any of it is relevant (though this occurs with all rust-analyzer settings removed except LinkedProjects):

{
    "files.watcherExclude": {
        "**/target/**": true
    },
    "files.insertFinalNewline": true,
    "files.trimFinalNewlines": true,
    "editor.formatOnSave": true,
    "rust-analyzer.linkedProjects": [
        "lib/Cargo.toml",
        "client/Cargo.toml",
        "server/Cargo.toml"
    ],
    "rust-analyzer.updates.askBeforeDownload": false,
    "rust-analyzer.updates.channel": "nightly",
    "rust-analyzer.diagnostics.disabled": [
        "missing-unsafe"
    ],
    "rust-analyzer.checkOnSave.enable": false,
    "rust-analyzer.assist.importPrefix": "by_crate",
    "rust-analyzer.trace.server": "verbose",
    "rust-analyzer.trace.extension": true
}

status after saving 1 file:

workspaces:
40 packages loaded
235 packages loaded
137 packages loaded

analysis:
6354 (60mb) files
0 (0b) index symbols
4096 trees, 128 retained
55226 trees, 128 retained (macros)
1243mb total

counts:
all counts are zero


requests:
  103 textDocument/formatting             4057ms
  111 rust-analyzer/inlayHints            16ms
  112 textDocument/semanticTokens/full/delta10ms
  113 textDocument/foldingRange           1ms
  115 textDocument/codeAction             0ms
  117 textDocument/codeLens               0ms
  118 codeLens/resolve                    0ms
  119 textDocument/documentSymbol         1ms
* 106 textDocument/documentSymbol         4ms
  110 codeLens/resolve                    4ms

RALS trace output (what I hope is the relevant portion. this is followed by ~20k lines of other stuff that doesn't appear directly relevant):

[Trace - 3:33:54 PM] Sending request 'textDocument/formatting - (478)'.
Params: {
    "textDocument": {
        "uri": "file:///path/to/graphics.rs"
    },
    "options": {
        "tabSize": 4,
        "insertSpaces": true,
        "trimFinalNewlines": true,
        "insertFinalNewline": true
    }
}

[Trace - 3:33:59 PM] Received response 'textDocument/formatting - (478)' in 4780ms.
Result: [
    {
        "range": {
            "start": {
                "line": 33,
                "character": 0
            },
            "end": {
                "line": 33,
                "character": 1
            }
        },
        "newText": ""
    }
]

There is no RA client output.

There don't seem to be any errors in any log anywhere, it just takes 3-15 seconds to format a file.

I would just use RLS, but RA has better auto-completion, so I'd love any advice on how to figure out what the problem is.

Edit: I tested on a completely fresh (cargo new) project (with no settings except format on save) and it was faster (~1s on the default main.rs, 1-2 seconds on some examples I pasted from rust by example) but still dramatically slower than the Rust extension or cargo fmt.

2

Most of the time it is fast for me (i9 CPU), but very seldom it gets really slow.

3

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