perf script: Add drop monitor script

A while back I created the dropmonitor protocol, which allowed users to get
reports of dropped frames communicated to them via a netlink socket.

While useful, several people have now asked that I integrate the ability
to do drop monitoring with perf, so they don't have to run additional
tools.

This patch adds a drop monitor script to the perf suite, and provides
the same output that the netlink socket does.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309801217-22450-1-git-send-email-nhorman@tuxdriver.com
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 78 insertions, 0 deletions

diff --git a/tools/perf/scripts/python/bin/net_dropmonitor-record b/tools/perf/scripts/python/bin/net_dropmonitor-record
new file mode 100755
index 000000000000..423fb81dadae
--- /dev/null
+++ b/tools/perf/scripts/python/bin/net_dropmonitor-record
@@ -0,0 +1,2 @@
+#!/bin/bash
+perf record -e skb:kfree_skb $@
diff --git a/tools/perf/scripts/python/bin/net_dropmonitor-report b/tools/perf/scripts/python/bin/net_dropmonitor-report
new file mode 100755
index 000000000000..8d698f5a06aa
--- /dev/null
+++ b/tools/perf/scripts/python/bin/net_dropmonitor-report
@@ -0,0 +1,4 @@
+#!/bin/bash
+# description: display a table of dropped frames
+
+perf script -s "$PERF_EXEC_PATH"/scripts/python/net_dropmonitor.py $@
diff --git a/tools/perf/scripts/python/net_dropmonitor.py b/tools/perf/scripts/python/net_dropmonitor.py
new file mode 100755
index 000000000000..a4ffc9500023
--- /dev/null
+++ b/tools/perf/scripts/python/net_dropmonitor.py
@@ -0,0 +1,72 @@
+# Monitor the system for dropped packets and proudce a report of drop locations and counts
+
+import os
+import sys
+
+sys.path.append(os.environ['PERF_EXEC_PATH'] + \
+                '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
+
+from perf_trace_context import *
+from Core import *
+from Util import *
+
+drop_log = {}
+kallsyms = []
+
+def get_kallsyms_table():
+        global kallsyms
+        try:
+                f = open("/proc/kallsyms", "r")
+                linecount = 0
+                for line in f:
+                        linecount = linecount+1
+                f.seek(0)
+        except:
+                return
+
+
+        j = 0
+        for line in f:
+                loc = int(line.split()[0], 16)
+                name = line.split()[2]
+                j = j +1
+                if ((j % 100) == 0):
+                        print "\r" + str(j) + "/" + str(linecount),
+                kallsyms.append({ 'loc': loc, 'name' : name})
+
+        print "\r" + str(j) + "/" + str(linecount)
+        kallsyms.sort()
+        return
+
+def get_sym(sloc):
+        loc = int(sloc)
+        for i in kallsyms:
+                if (i['loc'] >= loc):
+                        return (i['name'], i['loc']-loc)
+        return (None, 0)
+
+def print_drop_table():
+        print "%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT")
+        for i in drop_log.keys():
+                (sym, off) = get_sym(i)
+                if sym == None:
+                        sym = i
+                print "%25s %25s %25s" % (sym, off, drop_log[i])
+
+
+def trace_begin():
+        print "Starting trace (Ctrl-C to dump results)"
+
+def trace_end():
+        print "Gathering kallsyms data"
+        get_kallsyms_table()
+        print_drop_table()
+
+# called from perf, when it finds a correspoinding event
+def skb__kfree_skb(name, context, cpu, sec, nsec, pid, comm,
+                        skbaddr, protocol, location):
+        slocation = str(location)
+        try:
+                drop_log[slocation] = drop_log[slocation] + 1
+        except:
+                drop_log[slocation] = 1