-----Original Message-----
From: acrn-dev@... [mailto:acrn-dev@...]
On Behalf Of Zhipeng Gong
Sent: Monday, August 13, 2018 10:20 AM
To: acrn-dev@...
Subject: [acrn-dev] [PATCH] tools: acrntrace: Add ring buffer mode

When running longevity test and capture acrntrace, generated acrntrace files
sizes are too big.
Sometimes we don't care very old trace. This patch adds ring buffer mode,
fixes acrntrace file size and overwrites old trace with new trace.

Signed-off-by: Zhipeng Gong <zhipeng.gong@...>
---
tools/acrntrace/acrntrace.c | 44
+++++++++++++++++++++++++++++++++++++++++---
tools/acrntrace/acrntrace.h | 1 +
2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/tools/acrntrace/acrntrace.c b/tools/acrntrace/acrntrace.c index
39fda35..371ffaa 100644
--- a/tools/acrntrace/acrntrace.c
+++ b/tools/acrntrace/acrntrace.c
@@ -37,16 +37,19 @@ static char trace_file_dir[TRACE_FILE_DIR_LEN];

static reader_struct *reader;
static int pcpu_num = 0;
+static int ring_buffer_size = 0;

static void display_usage(void)
{
printf("acrntrace - tool to collect ACRN trace data\n"
- "[Usage] acrntrace [-i] [period in msec] [-ch]\n\n"
+ "[Usage] acrntrace [-i] [period in msec] [-r] [ring buffer size] [-
ch]\n\n"
"[Options]\n"
"\t-h: print this message\n"
"\t-i: period_in_ms: specify polling interval [1-999]\n"
"\t-t: max time to capture trace data (in second)\n"
- "\t-c: clear the buffered old data\n");
+ "\t-c: clear the buffered old data\n"
+ "\t-r: ring_buffer_size (in MB): enable ring buffer mode,"
+ " where new trace overwrites old trace when full\n");
}

static void timer_handler(union sigval sv) @@ -113,6 +116,15 @@ static int
parse_opt(int argc, char *argv[])
timeout = ret;
pr_dbg("Capture trace data for at most %ds\n", ret);
break;
+ case 'r':
+ ret = atoi(optarg);
+ if (ret <= 0) {
+ pr_err("'-r' require integer greater than 0\n");
+ return -EINVAL;
+ }
+ ring_buffer_size = ret * 1024 * 1024;
+ pr_dbg("Ring buffer size is %dM\n", ret);
+ break;
case 'c':
flags |= FLAG_CLEAR_BUF;
break;
@@ -206,6 +218,15 @@ static void reader_fn(param_t * param)
trace_ev_t e;
struct statvfs stat;
uint64_t freespace;
+ int pos = 0;
+
+ if (ring_buffer_size != 0) {
+ param->buffer = malloc(ring_buffer_size);
+ if (!param->buffer) {
+ perror("Failed to allocate ring buffer\n");
+ return;
+ }
+ }

pr_dbg("reader thread[%lu] created for FILE*[0x%p]\n",
pthread_self(), fp);
@@ -219,7 +240,13 @@ static void reader_fn(param_t * param)

while (1) {
do {
- ret = sbuf_write(fd, sbuf);
+ if (ring_buffer_size != 0) {
+ ret = sbuf_get(sbuf, param->buffer + pos);
+ pos += sbuf->ele_size;
+ if (pos + sbuf->ele_size > ring_buffer_size)
+ pos = 0;
+ } else
+ ret = sbuf_write(fd, sbuf);
} while (ret > 0);

usleep(period);
@@ -284,6 +311,17 @@ static void destory_reader(reader_struct * reader)
reader->thrd = 0;
}

+ if (ring_buffer_size != 0 && reader->param.buffer) {
+ int ret;
+
+ ret = write(reader->param.trace_fd, reader->param.buffer,
+ ring_buffer_size);
+ if (ret != ring_buffer_size) {
+ perror("Failed to write ring buffer\n");
+ }
+ free(reader->param.buffer);
+ }
+
if (reader->param.sbuf) {
munmap(reader->param.sbuf, MMAP_SIZE);
reader->param.sbuf = NULL;
diff --git a/tools/acrntrace/acrntrace.h b/tools/acrntrace/acrntrace.h index
ea54f4d..6615157 100644
--- a/tools/acrntrace/acrntrace.h
+++ b/tools/acrntrace/acrntrace.h
@@ -76,6 +76,7 @@ typedef struct {
int trace_fd;
shared_buf_t *sbuf;
pthread_mutex_t *sbuf_lock;
+ uint8_t *buffer;
} param_t;

typedef struct {
--
2.7.4