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Remove internal JIT and GC stress environment variables from public documentation #49102

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gewarren merged 2 commits into from
Oct 13, 2025
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Remove internal JIT and GC stress environment variables from public documentation #49102

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Copilot Oct 12, 2025
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Remove DOTNET_Jit* and DOTNET_GC* documentation
Copilot Oct 12, 2025
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28 changes: 0 additions & 28 deletions docs/core/tools/dotnet-environment-variables.md
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Expand Up @@ -111,34 +111,6 @@ The same can be achieved via the environment variable `DOTNET_SYSTEM_NET_HTTP_US
> [!NOTE]
> Starting in .NET 5, this setting to use <xref:System.Net.Http.HttpClientHandler> is no longer available.

### `DOTNET_Jit*` and `DOTNET_GC*`

There are two stressing-related features for the JIT and JIT-generated GC information: JIT Stress and GC Hole Stress. These features provide a way during development to discover edge cases and more "real world" scenarios without having to develop complex applications. The following environment variables are available:

- `DOTNET_JitStress`
- `DOTNET_JitStressModeNamesOnly`
- `DOTNET_GCStress`

#### JIT stress

Enabling JIT Stress can be done in several ways. Set `DOTNET_JitStress` to a non-zero integer value to generate varying levels of JIT optimizations based on a hash of the method's name. To apply all optimizations set `DOTNET_JitStress=2`, for example. Another way to enable JIT Stress is by setting `DOTNET_JitStressModeNamesOnly=1` and then requesting the stress modes, space-delimited, in the `DOTNET_JitStressModeNames` variable.

As an example, consider:

```
DOTNET_JitStressModeNames=STRESS_USE_CMOV STRESS_64RSLT_MUL STRESS_LCL_FLDS
```

#### GC Hole stress

Enabling GC Hole Stress causes GCs to always occur in specific locations and that helps to track down GC holes. GC Hole Stress can be enabled using the `DOTNET_GCStress` environment variable.

For more information, see [Investigating JIT and GC Hole stress](https://github.com/dotnet/runtime/blob/main/docs/design/coreclr/jit/investigate-stress.md).

#### JIT memory barriers

The code generator for Arm64 allows all `MemoryBarriers` instructions to be removed by setting `DOTNET_JitNoMemoryBarriers` to `1`.

### `DOTNET_RUNNING_IN_CONTAINER` and `DOTNET_RUNNING_IN_CONTAINERS`

The official .NET images (Windows and Linux) set the well-known environment variables:
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