[igt-dev] [PATCH i-g-t 3/7] tools/intel_guc_logger: Get rid of configurable number of subbufs

[Michał Winiarski]

The tool should just work. If we're not able to keep up with GuC, we
should probably rework the logic in i915 rather than try to buffer more
here. There's plenty of room for improvement since the actual
information content in GuC log is usually around 50%.

Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
---
 tools/intel_guc_logger.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/tools/intel_guc_logger.c b/tools/intel_guc_logger.c
index fd49d968..c81e4d1e 100644
--- a/tools/intel_guc_logger.c
+++ b/tools/intel_guc_logger.c
@@ -44,7 +44,6 @@ pthread_t flush_thread;
 int verbosity_level = 4; /* by default capture logs at max verbosity */
 uint32_t produced, consumed;
 uint64_t total_bytes_written;
-int num_buffers = NUM_SUBBUFS;
 int relay_fd, outfile_fd = -1;
 uint32_t test_duration, max_filesize;
 pthread_cond_t underflow_cond, overflow_cond;
@@ -115,7 +114,7 @@ static void pull_data(void)
 	int ret;
 
 	pthread_mutex_lock(&mutex);
-	while (num_filled_bufs() >= num_buffers) {
+	while (num_filled_bufs() >= NUM_SUBBUFS) {
 		igt_debug("overflow, will wait, produced %u, consumed %u\n", produced, consumed);
 		/* Stall the main thread in case of overflow, as there are no
 		 * buffers available to store the new logs, otherwise there
@@ -125,7 +124,7 @@ static void pull_data(void)
 	};
 	pthread_mutex_unlock(&mutex);
 
-	ptr = read_buffer + (produced % num_buffers) * SUBBUF_SIZE;
+	ptr = read_buffer + (produced % NUM_SUBBUFS) * SUBBUF_SIZE;
 
 	/* Read the logs from relay buffer */
 	ret = read(relay_fd, ptr, SUBBUF_SIZE);
@@ -170,7 +169,7 @@ static void *flusher(void *arg)
 		};
 		pthread_mutex_unlock(&mutex);
 
-		ptr = read_buffer + (consumed % num_buffers) * SUBBUF_SIZE;
+		ptr = read_buffer + (consumed % NUM_SUBBUFS) * SUBBUF_SIZE;
 
 		ret = write(outfile_fd, ptr, SUBBUF_SIZE);
 		igt_assert_f(ret == SUBBUF_SIZE, "couldn't dump the logs in a file\n");
@@ -277,11 +276,11 @@ static void init_main_thread(void)
 		igt_assert_f(0, "SIGALRM handler registration failed\n");
 
 	/* Need an aligned pointer for direct IO */
-	ret = posix_memalign((void **)&read_buffer, PAGE_SIZE, num_buffers * SUBBUF_SIZE);
+	ret = posix_memalign((void **)&read_buffer, PAGE_SIZE, NUM_SUBBUFS * SUBBUF_SIZE);
 	igt_assert_f(ret == 0, "couldn't allocate the read buffer\n");
 
 	/* Keep the pages locked in RAM, avoid page fault overhead */
-	ret = mlock(read_buffer, num_buffers * SUBBUF_SIZE);
+	ret = mlock(read_buffer, NUM_SUBBUFS * SUBBUF_SIZE);
 	igt_assert_f(ret == 0, "failed to lock memory\n");
 
 	/* Enable the logging, it may not have been enabled from boot and so
@@ -308,11 +307,6 @@ static int parse_options(int opt, int opt_index, void *data)
 		igt_assert_f(out_filename, "Couldn't allocate the o/p filename\n");
 		igt_debug("logs to be stored in file %s\n", out_filename);
 		break;
-	case 'b':
-		num_buffers = atoi(optarg);
-		igt_assert_f(num_buffers > 0, "invalid input for -b option\n");
-		igt_debug("number of buffers to be used is %d\n", num_buffers);
-		break;
 	case 't':
 		test_duration = atoi(optarg);
 		igt_assert_f(test_duration > 0, "invalid input for -t option\n");
@@ -337,7 +331,6 @@ static void process_command_line(int argc, char **argv)
 	static struct option long_options[] = {
 		{"verbosity", required_argument, 0, 'v'},
 		{"outputfile", required_argument, 0, 'o'},
-		{"buffers", required_argument, 0, 'b'},
 		{"testduration", required_argument, 0, 't'},
 		{"size", required_argument, 0, 's'},
 		{"discard", no_argument, 0, 'd'},
@@ -347,12 +340,11 @@ static void process_command_line(int argc, char **argv)
 	const char *help =
 		"  -v --verbosity=level   verbosity level of GuC logging\n"
 		"  -o --outputfile=name   name of the output file, including the location, where logs will be stored\n"
-		"  -b --buffers=num       number of buffers to be maintained on logger side for storing logs\n"
 		"  -t --testduration=sec  max duration in seconds for which the logger should run\n"
 		"  -s --size=MB           max size of output file in MBs after which logging will be stopped\n"
 		"  -d --discard           discard the old/boot-time logs before entering into the capture loop\n";
 
-	igt_simple_init_parse_opts(&argc, argv, "v:o:b:t:s:d", long_options,
+	igt_simple_init_parse_opts(&argc, argv, "v:o:t:s:d", long_options,
 				   help, parse_options, NULL);
 }
 
-- 
2.14.3