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authorArnaldo Carvalho de Melo <acme@redhat.com>2011-01-29 15:44:29 -0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-01-30 11:37:38 -0200
commit877108e42b1b9ba64857c4030cf356ecc120fd18 (patch)
treeca41fa741081faa0f936b7296d721c84d1b89176 /tools/perf/python
parent8115d60c323dd9931b95221c0a392aeddc1d6ef3 (diff)
downloadlinux-877108e42b1b9ba64857c4030cf356ecc120fd18.tar.gz
perf tools: Initial python binding
First clarifying that this kind of binding is not a replacement or an equivalent to the 'perf script' way of using python with perf. The 'perf script' way is to process events and look at a given script for some python function that matches the events to pass each event for processing. This is a python module, i.e. everything is driven from the python script, that merely uses "import perf" or "from perf import". perf script is focused on tracepoints, this binding is focused on profiling as an initial target. More work is needed to make available tracepoint specific variables as event variables accessible via this binding. There is one example of such usage model, in tools/perf/python/twatch.py, a tool to watch "cycles" events together with task (fork, exit) and comm perf events. For now, due to me not being able to grok how python distutils cope with building C extensions outside the sources dir the install target just builds it, I'm using it as: [root@emilia linux]# export PYTHONPATH=~acme/git/build/perf/lib.linux-x86_64-2.6/ [root@emilia linux]# tools/perf/python/twatch.py cpu: 4, pid: 30126, tid: 30126 { type: mmap, pid: 30126, tid: 30126, start: 0x4, length: 0x82e9ca03, offset: 0, filename: } cpu: 6, pid: 47, tid: 47 { type: mmap, pid: 47, tid: 47, start: 0x6, length: 0xbef87c36, offset: 0, filename: } cpu: 1, pid: 0, tid: 0 { type: mmap, pid: 0, tid: 0, start: 0x1, length: 0x775d1904, offset: 0, filename: } cpu: 7, pid: 0, tid: 0 { type: mmap, pid: 0, tid: 0, start: 0x7, length: 0xc750aeb6, offset: 0, filename: } cpu: 5, pid: 2255, tid: 2255 { type: mmap, pid: 2255, tid: 2255, start: 0x5, length: 0x76669635, offset: 0, filename: } cpu: 0, pid: 0, tid: 0 { type: mmap, pid: 0, tid: 0, start: 0, length: 0x6422ef6b, offset: 0, filename: } cpu: 2, pid: 2255, tid: 2255 { type: mmap, pid: 2255, tid: 2255, start: 0x2, length: 0xe078757a, offset: 0, filename: } cpu: 1, pid: 5769, tid: 5769 { type: fork, pid: 30127, ppid: 5769, tid: 30127, ptid: 5769, time: 103893991270534} cpu: 6, pid: 30127, tid: 30127 { type: comm, pid: 30127, tid: 30127, comm: ls } cpu: 6, pid: 30127, tid: 30127 { type: exit, pid: 30127, ppid: 30127, tid: 30127, ptid: 30127, time: 103893993273024} The first 8 mmap events in this 8 way machine are a mistery that is still being investigated. More of the tools/perf/util/ APIs will be exposed via this python binding as the need arises. For now the focus is on creating events and processing them, symbol resolution is an obvious next step, with tracepoint variables as a close second step. Cc: Clark Williams <williams@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/python')
-rwxr-xr-xtools/perf/python/twatch.py41
1 files changed, 41 insertions, 0 deletions
diff --git a/tools/perf/python/twatch.py b/tools/perf/python/twatch.py
new file mode 100755
index 000000000000..5e9f3b7b7ee8
--- /dev/null
+++ b/tools/perf/python/twatch.py
@@ -0,0 +1,41 @@
+#! /usr/bin/python
+# -*- python -*-
+# -*- coding: utf-8 -*-
+# twatch - Experimental use of the perf python interface
+# Copyright (C) 2011 Arnaldo Carvalho de Melo <acme@redhat.com>
+#
+# This application is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; version 2.
+#
+# This application is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+
+import perf
+
+def main():
+ cpus = perf.cpu_map()
+ threads = perf.thread_map()
+ evsel = perf.evsel(task = 1, comm = 1, mmap = 0,
+ wakeup_events = 1, sample_period = 1,
+ sample_id_all = 1,
+ sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU | perf.SAMPLE_TID)
+ evsel.open(cpus = cpus, threads = threads);
+ evlist = perf.evlist()
+ evlist.add(evsel)
+ evlist.mmap(cpus = cpus, threads = threads)
+ while True:
+ evlist.poll(timeout = -1)
+ for cpu in cpus:
+ event = evlist.read_on_cpu(cpu)
+ if not event:
+ continue
+ print "cpu: %2d, pid: %4d, tid: %4d" % (event.sample_cpu,
+ event.sample_pid,
+ event.sample_tid),
+ print event
+
+if __name__ == '__main__':
+ main()