buffers: { size_kb: 100000 fill_policy: DISCARD } buffers: { size_kb: 2048 fill_policy: DISCARD } data_sources: { config { name: "linux.process_stats" target_buffer: 1 process_stats_config { scan_all_processes_on_start: true } } }

这是一个Perfetto的配置文件示例，用于指定系统跟踪的数据源和缓冲区设置。具体解释如下：

- buffers: { size_kb: 100000 fill_policy: DISCARD }：定义了一个缓冲区，大小为100000KB，当缓冲区满时，新的跟踪数据会覆盖旧的数据（fill_policy为DISCARD）。
- buffers: { size_kb: 2048 fill_policy: DISCARD }：定义了另一个缓冲区，大小为2048KB，用于存储一些较小的跟踪数据。
- data_sources: {}：定义了一个数据源，用于收集系统进程的状态信息。
- config {}: 定义了数据源的配置信息。
- name: "linux.process_stats"：指定数据源的名称为linux.process_stats。
- target_buffer: 1：指定数据源使用第二个缓冲区（buffers中的第二个）。
- process_stats_config {}：指定数据源为进程状态信息源，并指定其配置信息。
- scan_all_processes_on_start: true：指定在系统启动时扫描所有的进程信息。

该配置文件的作用是定义了两个缓冲区和一个数据源，并指定了数据源的名称、使用的缓冲区、以及数据源的配置信息。执行该配置文件可以启动Perfetto进行系统跟踪，并收集进程状态信息。

相关问题

Shader error in 'Custom/Circle': 'frag': Not all control paths return a value at line 47 (on d3d11) Compiling Subshader: 0, Pass: <Unnamed Pass 0>, Fragment program with <no keywords> Platform defines: SHADER_API_DESKTOP UNITY_COLORSPACE_GAMMA UNITY_ENABLE_DETAIL_NORMALMAP UNITY_ENABLE_REFLECTION_BUFFERS UNITY_LIGHTMAP_FULL_HDR UNITY_LIGHT_PROBE_PROXY_VOLUME UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BLENDING UNITY_SPECCUBE_BOX_PROJECTION UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS Disabled keywords: SHADER_API_GLES30 UNITY_ASTC_NORMALMAP_ENCODING UNITY_FRAMEBUFFER_FETCH_AVAILABLE UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS UNITY_HARDWARE_TIER1 UNITY_HARDWARE_TIER2 UNITY_HARDWARE_TIER3 UNITY_LIGHTMAP_DLDR_ENCODING UNITY_LIGHTMAP_RGBM_ENCODING UNITY_METAL_SHADOWS_USE_POINT_FILTERING UNITY_NO_DXT5nm UNITY_NO_FULL_STANDARD_SHADER UNITY_NO_SCREENSPACE_SHADOWS UNITY_PBS_USE_BRDF2 UNITY_PBS_USE_BRDF3 UNITY_PRETRANSFORM_TO_DISPLAY_ORIENTATION UNITY_UNIFIED_SHADER_PRECISION_MODEL UNITY_VIRTUAL_TEXTURING

根据错误信息来看，这个错误发生在Shader代码的第47行。错误信息显示：'frag'函数并不是所有的控制路径都返回一个值。

在你提供的Shader代码中，'frag'函数是片段着色器函数，它的返回类型是fixed4。根据错误提示，你需要确保'frag'函数的所有控制路径都返回一个值。

在你的代码中，如果距离dist大于半径_radius时，使用了'discard'语句来丢弃该像素。然而，在这种情况下，你没有返回任何颜色值。

为了解决这个错误，你可以在'discard'语句后添加一个默认的返回值，例如返回一个透明的颜色(fixed4(0,0,0,0))，或者根据需要返回其他颜色值。这样就可以确保'frag'函数的所有控制路径都返回一个值。

修正后的代码示例如下：

fixed4 frag(v2f i) : SV_TARGET0{
    float2 uv = i.uv;

    float dist = distance(uv, _Center.xy);

    if(dist <= _Radius)
    {
        fixed4 texColor  = tex2D(_MainTex, uv);
        return texColor * _Color;
    }
    else
    {
        discard;
        return fixed4(0,0,0,0); // 添加默认的返回值
    }
}

请注意，错误信息中还提到了编译平台和一些已禁用的关键字。这些信息可能与错误无关，只是提供了一些上下文信息。你应该主要关注错误信息中的具体错误描述和行号来解决问题。

read a received packet from the Ethernet buffers and send it to the lwIP for handling

To read a received packet from the Ethernet buffers and send it to lwIP for handling, you need to follow these steps:

1. Retrieve the packet from the Ethernet buffers. This can typically be done using DMA (Direct Memory Access) to transfer the packet from the Ethernet controller's buffer to a buffer in memory.

2. Check the packet header to determine whether it is an IP packet or not. If it is not an IP packet, you can discard it.

3. If the packet is an IP packet, pass it to lwIP for handling by calling the appropriate function. This function will typically be something like `ethernet_input()` or `ip_input()`, depending on the specific implementation.

4. Once the packet has been passed to lwIP, it will handle it according to its configured networking stack. This may involve routing the packet to its destination, processing any network protocols that are encapsulated within the packet, or performing other operations as needed.

5. After lwIP has finished handling the packet, it may generate a response packet that needs to be transmitted back out onto the network. To do this, you will need to use the Ethernet controller's transmit buffer to send the packet back out onto the network.

Overall, the process of reading a received packet from the Ethernet buffers and sending it to lwIP for handling can be complex, and will depend on the specific implementation of lwIP and the Ethernet controller being used. However, by following the general steps outlined above, you can begin to understand the basic flow of data through the networking stack.