vulkan: add MESA_VK_TRACE_PER_SUBMIT

To capture RGP per-submit for compute-only workloads. Other capture
tools like RMV are not covered here.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32370>

docs/envvars.rst

@@ -365,14 +365,21 @@ Core Mesa environment variables
    - Creating RMV captures requires the ``scripts/setup.sh`` script in the
      Radeon Developer Tools folder to be run beforehand
 
+.. envvar:: MESA_VK_TRACE_PER_SUBMIT
+
+   Enables per-submit capture for compute-only workload. Disabled by default
+   and only valid with MESA_VK_TRACE=rgp.
+
 .. envvar:: MESA_VK_TRACE_FRAME
 
    Specifies a frame index at which a trace capture is automatically triggered.
+   Ignored when MESA_VK_TRACE_PER_SUBMIT is enabled.
 
 .. envvar:: MESA_VK_TRACE_TRIGGER
 
    Specifies a trigger file. Creating the file triggers the capture. (e.g.
    ``export MESA_VK_TRACE_TRIGGER=/tmp/trigger`` and then ``touch /tmp/trigger``)
+   Ignored when MESA_VK_TRACE_PER_SUBMIT is enabled.
 
 .. envvar:: MESA_LOADER_DRIVER_OVERRIDE
 

src/vulkan/runtime/vk_instance.c

@@ -200,8 +200,11 @@ vk_instance_init(struct vk_instance *instance,
    }
 
    instance->trace_mode = parse_debug_string(getenv("MESA_VK_TRACE"), trace_options);
-   instance->trace_frame = (uint32_t)debug_get_num_option("MESA_VK_TRACE_FRAME", 0xFFFFFFFF);
-   instance->trace_trigger_file = secure_getenv("MESA_VK_TRACE_TRIGGER");
+   instance->trace_per_submit = debug_get_bool_option("MESA_VK_TRACE_PER_SUBMIT", false);
+   if (!instance->trace_per_submit) {
+      instance->trace_frame = (uint32_t)debug_get_num_option("MESA_VK_TRACE_FRAME", 0xFFFFFFFF);
+      instance->trace_trigger_file = secure_getenv("MESA_VK_TRACE_TRIGGER");
+   }
 
 #if !VK_LITE_RUNTIME_INSTANCE
    glsl_type_singleton_init_or_ref();

src/vulkan/runtime/vk_instance.h

@@ -173,6 +173,9 @@ struct vk_instance {
 
    uint32_t trace_frame;
    char *trace_trigger_file;
+
+   /** Whether the capture mode is per-submit. */
+   bool trace_per_submit;
 };
 
 VK_DEFINE_HANDLE_CASTS(vk_instance, base, VkInstance,