example of iolatencytop

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>

diff --git a/README.md b/README.md
index 829caca21d30c9899cb8cfb3888ff8521be95134..1a0172d53e8667d5e363a14826c5f4ee78bda66a 100644 (file)
--- a/README.md
+++ b/README.md
@@ -135,6 +135,40 @@ Open latency distribution (usec)
 74.077 █████                                                                 2
 ```
 
+#### I/O latency top
+```bash
+$ ./lttng-iolatencytop analysis-20150115-120942/ --limit 3 --minsize 2
+Checking the trace for lost events...
+Timerange: [2015-01-15 12:18:37.216484041, 2015-01-15 12:18:53.821580313]
+Top open syscall latencies (usec)
+Begin               End                  Name             Duration (usec)         Size  Proc                     PID      Filename      
+[12:18:50.432950815,12:18:50.870648568]  open                  437697.753          N/A  apache2                  31517    /var/lib/php5/sess_0ifir2hangm8ggaljdphl9o5b5 (fd=13)
+[12:18:52.946080165,12:18:52.946132278]  open                      52.113          N/A  apache2                  31588    /var/lib/php5/sess_mr9045p1k55vin1h0vg7rhgd63 (fd=13)
+[12:18:46.800846035,12:18:46.800874916]  open                      28.881          N/A  apache2                  31591    /var/lib/php5/sess_r7c12pccfvjtas15g3j69u14h0 (fd=13)
+[12:18:51.389797604,12:18:51.389824426]  open                      26.822          N/A  apache2                  31520    /var/lib/php5/sess_4sdb1rtjkhb78sabnoj8gpbl00 (fd=13)
+
+Top read syscall latencies (usec)
+Begin               End                  Name             Duration (usec)         Size  Proc                     PID      Filename      
+[12:18:37.256073107,12:18:37.256555967]  read                     482.860       7.00 B  bash                     10237    unknown (origin not found) (fd=3)
+[12:18:52.000209798,12:18:52.000252304]  read                      42.506      1.00 KB  irqbalance               1337     /proc/interrupts (fd=3)
+[12:18:37.256559439,12:18:37.256601615]  read                      42.176       5.00 B  bash                     10237    unknown (origin not found) (fd=3)
+[12:18:42.000281918,12:18:42.000320016]  read                      38.098      1.00 KB  irqbalance               1337     /proc/interrupts (fd=3)
+
+Top write syscall latencies (usec)
+Begin               End                  Name             Duration (usec)         Size  Proc                     PID      Filename      
+[12:18:49.913241516,12:18:49.915908862]  write                   2667.346      95.00 B  apache2                  31584    /var/log/apache2/access.log (fd=8)
+[12:18:37.472823631,12:18:37.472859836]  writev                    36.205     21.97 KB  apache2                  31544    unknown (origin not found) (fd=12)
+[12:18:37.991578372,12:18:37.991612724]  writev                    34.352     21.97 KB  apache2                  31589    unknown (origin not found) (fd=12)
+[12:18:39.547778549,12:18:39.547812515]  writev                    33.966     21.97 KB  apache2                  31584    unknown (origin not found) (fd=12)
+
+Top sync syscall latencies (usec)
+Begin               End                  Name             Duration (usec)         Size  Proc                     PID      Filename      
+[12:18:50.162776739,12:18:51.157522361]  sync                  994745.622          N/A  sync                     22791    None (fd=None)
+[12:18:37.227867532,12:18:37.232289687]  sync_file_range         4422.155          N/A  lttng-consumerd          19964    /home/julien/lttng-traces/analysis-20150115-120942/kernel/metadata (fd=32)
+[12:18:37.238076585,12:18:37.239012027]  sync_file_range          935.442          N/A  lttng-consumerd          19964    /home/julien/lttng-traces/analysis-20150115-120942/kernel/metadata (fd=32)
+[12:18:37.220974711,12:18:37.221647124]  sync_file_range          672.413          N/A  lttng-consumerd          19964    /home/julien/lttng-traces/analysis-20150115-120942/kernel/metadata (fd=32)
+```
+
 #### I/O operations log
 ```bash
 $ ./lttng-iolog mytrace/