Add iodevstats.stp example

2 files changed, 52 insertions, 0 deletions

diff --git a/testsuite/systemtap.examples/io/iodevstats.meta b/testsuite/systemtap.examples/io/iodevstats.meta
new file mode 100644
index 00000000..89277d2f
--- /dev/null
+++ b/testsuite/systemtap.examples/io/iodevstats.meta
@@ -0,0 +1,13 @@
+title: List Executables Reading and Writing the Most Data by Device
+name: iodevstats.stp
+version: 1.0
+author: anonymous
+keywords: io profiling
+subsystem: io
+status: production
+exit: user-controlled
+output: sorted-list
+scope: system-wide
+description:  The iodevstats.stp script measures the amount of data successfully read and written by all the executables for each io device on the system.  The output is sorted from greatest sum of bytes read and written to a device by an executable to the least. The output contains device major/minor number, the count of operations (reads and writes), the totals and averages for the number of bytes read and written.
+test_check: stap -p4 iodevstats.stp
+test_installcheck: stap iodevstats.stp -c "sleep 0.2"
diff --git a/testsuite/systemtap.examples/io/iodevstats.stp b/testsuite/systemtap.examples/io/iodevstats.stp
new file mode 100755
index 00000000..8925945f
--- /dev/null
+++ b/testsuite/systemtap.examples/io/iodevstats.stp
@@ -0,0 +1,39 @@
+#! /usr/bin/env stap
+global reads, writes, totals
+
+probe begin { printf("starting probe\n") }
+
+probe vfs.read.return {
+  count = $return
+  if ( count >= 0 ) {
+    e=execname();
+    reads[e,dev] <<< count # statistics array
+    totals[e,dev] += count
+  }
+}
+
+probe vfs.write.return {
+  count = $return
+  if (count >= 0 ) {
+    e=execname();
+    writes[e,dev] <<< count # statistics array
+    totals[e,dev] += count
+  }
+}
+
+probe end {
+  printf("\n%16s %8s %8s %8s %8s %8s %8s %8s\n",
+    "", "", "", "read", "read", "", "write", "write")
+  printf("%16s %8s %8s %8s %8s %8s %8s %8s\n",
+    "name", "device", "read", "KB tot", "B avg", "write", "KB tot", "B avg")
+  foreach ([name,dev] in totals- limit 20) { # sort by total io
+    printf("%16s %3d, %4d %8d %8d %8d %8d %8d %8d\n",
+      name, _dev_major(dev),  _dev_minor(dev),
+      @count(reads[name,dev]),
+      (@count(reads[name,dev]) ? @sum(reads[name,dev])>>10 : 0 ),
+      (@count(reads[name,dev]) ? @avg(reads[name,dev]) : 0 ),
+      @count(writes[name,dev]),
+      (@count(writes[name,dev]) ? @sum(writes[name,dev])>>10 : 0 ),
+      (@count(writes[name,dev]) ? @avg(writes[name,dev]) : 0 ))
+  }
+}