blkparse: add hint for discarded drv_data traces

Display an informational message on blkparse exit to notify users that
additional data was available which would require to be dumped to binary
output.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/blkparse.c b/blkparse.c
index 24e2d923d19fc8fcd7e85b41c468abe312c11fda..3177a41dc750141afd5872fd2decbd39df622b0d 100644 (file)
--- a/blkparse.c
+++ b/blkparse.c
@@ -292,6 +292,8 @@ static volatile int done;
 struct timespec                abs_start_time;
 static unsigned long long start_timestamp;
 
+static int have_drv_data = 0;
+
 #define JHASH_RANDOM   (0x3af5f2ee)
 
 #define CPUS_PER_LONG  (8 * sizeof(unsigned long))
@@ -1584,6 +1586,7 @@ static void dump_trace_fs(struct blk_io_trace *t, struct per_dev_info *pdi,
                        log_generic(pci, t, "A");
                        break;
                case __BLK_TA_DRV_DATA:
+                       have_drv_data = 1;
                        /* dump to binary file only */
                        break;
                default:
@@ -2844,6 +2847,10 @@ int main(int argc, char *argv[])
        if (!ret)
                show_stats();
 
+       if (have_drv_data && !dump_binary)
+               printf("\ndiscarded traces containing low-level device driver "
+                      "specific data (only available in binary output)\n");
+
        if (ofp_buffer) {
                fflush(ofp);
                free(ofp_buffer);