radv: replace RADV_TRACE_FILE by RADV_DEBUG=hang

The trace file will be dumped as part of the hang report into
$HOME/radv_dumps_<pid>/trace.log if a GPU hang is detected.

The old and famous RADV_TRACE_FILE envvar is now deprecated.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7233>

docs/envvars.rst

@@ -554,6 +554,9 @@ RADV driver environment variables
    ``forcecompress``
       Enables DCC,FMASK,CMASK,HTILE in situations where the driver supports it
       but normally does not deem it beneficial.
+   ``hang``
+      enable GPU hangs detection and dump a report to $HOME/radv_dumps_<pid>
+      if a GPU hang is detected
    ``info``
       show GPU-related information
    ``metashaders``
@@ -624,8 +627,6 @@ RADV driver environment variables
 
 ``RADV_TEX_ANISO``
    force anisotropy filter (up to 16)
-``RADV_TRACE_FILE``
-   generate cmdbuffer tracefiles when a GPU hang is detected
 ``ACO_DEBUG``
    a comma-separated list of named flags, which do various things:
 

src/amd/vulkan/radv_debug.c

@@ -83,19 +83,10 @@ radv_init_trace(struct radv_device *device)
 }
 
 static void
-radv_dump_trace(struct radv_device *device, struct radeon_cmdbuf *cs)
+radv_dump_trace(struct radv_device *device, struct radeon_cmdbuf *cs, FILE *f)
 {
-	const char *filename = getenv("RADV_TRACE_FILE");
-	FILE *f = fopen(filename, "w");
-
-	if (!f) {
-		fprintf(stderr, "Failed to write trace dump to %s\n", filename);
-		return;
-	}
-
 	fprintf(f, "Trace ID: %x\n", *device->trace_id_ptr);
 	device->ws->cs_dump(cs, f, (const int*)device->trace_id_ptr, 2);
-	fclose(f);
 }
 
 static void
@@ -625,8 +616,6 @@ radv_check_gpu_hangs(struct radv_queue *queue, struct radeon_cmdbuf *cs)
 
 	fprintf(stderr, "radv: GPU hang detected...\n");
 
-	radv_dump_trace(queue->device, cs);
-
 	/* Create a directory into $HOME/radv_dumps_<pid> to save various
 	 * debugging info about that GPU hang.
 	 */
@@ -638,6 +627,14 @@ radv_check_gpu_hangs(struct radv_queue *queue, struct radeon_cmdbuf *cs)
 		abort();
 	}
 
+	/* Dump trace file. */
+	snprintf(dump_path, sizeof(dump_path), "%s/%s", dump_dir, "trace.log");
+	f = fopen(dump_path, "w+");
+	if (f) {
+		radv_dump_trace(queue->device, cs, f);
+		fclose(f);
+	}
+
 	/* Dump pipeline state. */
 	snprintf(dump_path, sizeof(dump_path), "%s/%s", dump_dir, "pipeline.log");
 	f = fopen(dump_path, "w+");

src/amd/vulkan/radv_debug.h

@@ -57,6 +57,7 @@ enum {
 	RADV_DEBUG_DISCARD_TO_DEMOTE = 1 << 26,
 	RADV_DEBUG_LLVM              = 1 << 27,
 	RADV_DEBUG_FORCE_COMPRESS    = 1 << 28,
+	RADV_DEBUG_HANG              = 1 << 29,
 };
 
 enum {

src/amd/vulkan/radv_device.c

@@ -530,6 +530,7 @@ static const struct debug_control radv_debug_options[] = {
 	{"discardtodemote", RADV_DEBUG_DISCARD_TO_DEMOTE},
 	{"llvm", RADV_DEBUG_LLVM},
 	{"forcecompress", RADV_DEBUG_FORCE_COMPRESS},
+	{"hang", RADV_DEBUG_HANG},
 	{NULL, 0}
 };
 
@@ -2794,19 +2795,25 @@ VkResult radv_CreateDevice(
 		device->physical_device->rad_info.family == CHIP_HAWAII ? 4096 : 8192;
 
 	if (getenv("RADV_TRACE_FILE")) {
-		const char *filename = getenv("RADV_TRACE_FILE");
+		fprintf(stderr, "***********************************************************************************\n");
+		fprintf(stderr, "* WARNING: RADV_TRACE_FILE=<file> is deprecated and replaced by RADV_DEBUG=hang *\n");
+		fprintf(stderr, "***********************************************************************************\n");
+		abort();
+	}
 
+	if (device->instance->debug_flags & RADV_DEBUG_HANG) {
+		/* Enable GPU hangs detection and dump logs if a GPU hang is
+		 * detected.
+		 */
 		keep_shader_info = true;
 
 		if (!radv_init_trace(device))
 			goto fail;
 
 		fprintf(stderr, "*****************************************************************************\n");
-		fprintf(stderr, "* WARNING: RADV_TRACE_FILE is costly and should only be used for debugging! *\n");
+		fprintf(stderr, "* WARNING: RADV_DEBUG=hang is costly and should only be used for debugging! *\n");
 		fprintf(stderr, "*****************************************************************************\n");
 
-		fprintf(stderr, "Trace file will be dumped to %s\n", filename);
-
 		/* Wait for idle after every draw/dispatch to identify the
 		 * first bad call.
 		 */