kernel.git/tools/perf/util/event.c, branch linux-3.6.y

perf tools: Ensure comm string is properly terminated

2012-02-29T21:29:45Z

If threads in a multi-threaded process have names shorter than the main thread the comm for the named threads is not properly terminated. E.g., for the process 'namedthreads' where each thread is named noploop%d where %d is the thread number: Before: perf script -f comm,tid,ip,sym,dso noploop:4ads 21616 400a49 noploop (/tmp/namedthreads) The 'ads' in the thread comm bleeds over from the process name. After: perf script -f comm,tid,ip,sym,dso noploop:4 21616 400a49 noploop (/tmp/namedthreads) Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1330111898-68071-1-git-send-email-dsahern@gmail.com Signed-off-by: David Ahern Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix prefix matching for kernel maps

2012-02-06T20:57:39Z

In some perf ancient versions we used '[kernel.kallsyms._text]' as the name for the kernel map. This got changed with commit: perf: 'perf kvm' tool for monitoring guest performance from host commit a1645ce12adb6c9cc9e19d7695466204e3f017fe Author: Zhang, Yanmin and we started to use following name '[kernel.kallsyms]_text'. This name change is important for the report code dealing with ancient perf data. When processing the kernel map event, we need to recognize the old naming (dont match the last ']') and initialize the kernel map correctly. The subsequent call to maps__set_kallsyms_ref_reloc_sym deals with the superfluous ']' to get correct symbol name. Cc: Corey Ashford Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1328461865-6127-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Look up thread names for system wide profiling

2011-12-23T18:33:57Z

This handles multithreaded processes with named threads when doing system wide profiling: the comm for each thread is looked up allowing them to be different from the thread group leader. v2: - fixed sizeof arg to perf_event__get_comm_tgid Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1324578603-12762-3-git-send-email-dsahern@gmail.com Signed-off-by: David Ahern Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix comm for processes with named threads

2011-12-23T18:10:40Z

perf does not properly handle monitoring of processes with named threads. For example: $ ps -C myapp -L PID LWP TTY TIME CMD 25118 25118 ? 00:00:00 myapp 25118 25119 ? 00:00:00 myapp:worker perf record -e cs -c 1 -fo /tmp/perf.data -p 25118 -- sleep 10 perf report --stdio -i /tmp/perf.data 100.00% myapp:worker [kernel.kallsyms] [k] perf_event_task_sched_out The process name is set to the name of the last thread it finds for the process. The Problem: perf-top and perf-record both create a thread_map of threads to be monitored. That map is used in perf_event__synthesize_thread_map which loops over the entries in thread_map and calls __event__synthesize_thread to generate COMM and MMAP events. __event__synthesize_thread calls perf_event__synthesize_comm which opens /proc/pid/status, reads the name of the task and its thread group id. That's all fine. The problem is that it then reads /proc/pid/task and generates COMM events for each task it finds - but using the name found in /proc/pid/status where pid is the thread of interest. The end result (looping over thread_map + synthesizing comm events for each thread each time) means the name of the last thread processed sets the name for all threads in the process - which is not good for multithreaded processes with named threads. The Fix: perf_event__synthesize_comm has an input argument (full) that decides whether to process task entries for each pid it is passed. It currently never set to 0 (perf_event__synthesize_comm has a single caller and it always passes the value 1). Let's fix that. Add the full input argument to __event__synthesize_thread which passes it to perf_event__synthesize_comm. For thread/process monitoring set full to 0 which means COMM and MMAP events are only generated for the pid passed to it. For system wide monitoring set full to 1 so that COMM events are generated for all threads in a process. Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1324578603-12762-2-git-send-email-dsahern@gmail.com Signed-off-by: David Ahern Signed-off-by: Arnaldo Carvalho de Melo

perf events: Tidy up perf_event__preprocess_sample

2011-12-20T15:50:59Z

Use local variable 'dso' to reduce typing a bit and rearrange the if condition. Also NULL check of al->map in the condition is not necessary. Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1323703017-6060-7-git-send-email-namhyung@gmail.com Signed-off-by: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf event: Introduce perf_event__fprintf

2011-12-02T13:06:37Z

So that tools like 'perf test' can print the events when in verbose mode, for instance. Cc: David Ahern Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-xnovdqfi25nc48gy6604k7yp@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Rename perf_event_ops to perf_tool

2011-11-28T12:39:28Z

To better reflect that it became the base class for all tools, that must be in each tool struct and where common stuff will be put. Cc: David Ahern Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-qgpc4msetqlwr8y2k7537cxe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Resolve machine earlier and pass it to perf_event_ops

2011-11-28T12:39:12Z

Reducing the exposure of perf_session further, so that we can use the classes in cases where no perf.data file is created. Cc: David Ahern Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-stua66dcscsezzrcdugvbmvd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Pass tool context in the the perf_event_ops functions

2011-11-28T12:38:56Z

So that we don't need to have that many globals. Next steps will remove the 'session' pointer, that in most cases is not needed. Then we can rename perf_event_ops to 'perf_tool' that better describes this class hierarchy. Cc: David Ahern Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-wp4djox7x6w1i2bab1pt4xxp@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Synthesize anonymous mmap events

2011-09-23T17:37:06Z

perf_event__synthesize_mmap_events does not create anonymous mmap events even though the kernel does. As a result an already running application with dynamically created code will not get profiled - all samples end up in the unknown bucket. This patch skips any entries with '[' in the name to avoid adding events for special regions (eg the vsyscall page). All other executable mmaps are assumed to be anonymous and an event is synthesized. Acked-by: Pekka Enberg Cc: Eric B Munson Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Pekka Enberg Link: http://lkml.kernel.org/r/20110830091506.60b51fe8@kryten Signed-off-by: Anton Blanchard Signed-off-by: Arnaldo Carvalho de Melo