linux-stable.git/tools/perf/util/evlist.c, branch linux-4.2.y

perf evlist: Propagate thread maps through the evlist

2015-06-25T18:15:51+00:00

Propagate evlist's thread_map object through all the evsel objects.

It'll be handy to access evsel's threads directly in following patches.
The reason is there's no link from evsel to evlist which hold threads
map now and evlist is not always available.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1435012588-9007-7-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Propagate cpu maps to evsels in an evlist

2015-06-25T18:15:51+00:00

Propagate evlist's cpu_map object through all the evsel objects, while
keeping already configured evsel->cpus.

It'll be handy to access evsel's cpus directly in following patches.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1435012588-9007-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add reference counting for thread_map object

2015-06-25T18:15:50+00:00

Adding reference counting for thread_map object, so it could be easily
shared among other objects.

Using thread_map__put instead thread_map__delete and making
thread_map__delete static.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1435012588-9007-5-git-send-email-jolsa@kernel.org
[ Adjustments to move it ahead of the "comm" patches ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add reference counting for cpu_map object

2015-06-25T18:15:50+00:00

Adding refference counting for cpu_map object, so it could be easily
shared among other objects.

Using cpu_map__put instead cpu_map__delete and making cpu_map__delete
static.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1435012588-9007-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf thread_map: Don't access the array entries directly

2015-06-23T21:21:44+00:00

Instead provide a method to set the array entries, and another to access
the contents.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1435012588-9007-2-git-send-email-jolsa@kernel.org
[ Split providing the set/get accessors from transforming the entries structs ]
Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Add toggle_enable() method

2015-06-17T19:40:26+00:00

For an upcoming feature in 'perf top' we will have a hotkey to
enable/disable events, so remember if the events in the list are
enabled or disabled and allows toggling this state using a new
method.

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-64c4jvdl5feg2zhimxvokqka@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Fix race condition at the end of started workloads

2015-06-17T19:38:48+00:00

I get following crash on multiple systems and across several releases
(at least since v3.18).

	Core was generated by `/tmp/perf trace sleep 0.2 '.
	Program terminated with signal SIGSEGV, Segmentation fault.
	#0  perf_mmap__read_head (mm=0x3fff9bf30070) at util/evlist.h:195
	195		u64 head = ACCESS_ONCE(pc->data_head);
	(gdb) bt
	#0  perf_mmap__read_head (mm=0x3fff9bf30070) at util/evlist.h:195
	#1  perf_evlist__mmap_read (evlist=0x10027f11910, idx=)
	    at util/evlist.c:637
	#2  0x000000001003ce4c in trace__run (argv=,
	    argc=, trace=0x3fffd7b28288) at builtin-trace.c:2259
	#3  cmd_trace (argc=, argv=,
	    prefix=) at builtin-trace.c:2799
	#4  0x00000000100657b8 in run_builtin (p=0x10176798 , argc=3,
	    argv=0x3fffd7b2b550) at perf.c:370
	#5  0x00000000100063e8 in handle_internal_command (argv=0x3fffd7b2b550, argc=3)
	    at perf.c:429
	#6  run_argv (argv=0x3fffd7b2af70, argcp=0x3fffd7b2af7c) at perf.c:473
	#7  main (argc=3, argv=0x3fffd7b2b550) at perf.c:588

The problem seems to be a race condition, when the application has just
exited.  Some/all fds associated with the perf-events (tracepoints) go
into a POLLHUP/ POLLERR state and the mmap region associated with those
events are unmapped (in perf_evlist__filter_pollfd()).

But we go back and do a perf_evlist__mmap_read() which assumes that the
mmaps are still valid and we hit the crash.

If the mapping for an event is released, its refcnt is 0 (and ->base
is NULL), so ensure we have non-zero refcount before accessing the map.

Note that perf-record has a similar logic but unlike perf-trace, the
record__mmap_read_all() checks the evlist->mmap[i].base before accessing
the map.

Signed-off-by: Sukadev Bhattiprolu 
Cc: Jiri Olsa 
Cc: Li Zhang 
Link: http://lkml.kernel.org/r/20150612060003.GA19913@us.ibm.com
[ Fixed it up to use atomic_read() ]
Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Use atomic.h for the perf_mmap refcount

2015-05-15T18:45:16+00:00

Now that we have atomic.h, we should convert all of the existing
refcounts to use it.

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-qhpv2etncj3hfofgj1aitkyv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Amend mmap ref counting for the AUX area mmap

2015-05-04T15:43:48+00:00

Reference counting of the mmap buffer does not work correctly when there
is an AUX area mmap also.

In snapshot mode it is not easy to know if the AUX area mmap buffer
contains usefull information. Equally the evlist does not know if the
recording is in sanpshot mode anyway.

Consequently, for now just assume the AUX area mmap always has data,
which will just cause the mmap buffer to remain mmapped for the duration
of the recording.

Signed-off-by: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1429903807-20559-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Extend -m option for AUX area tracing mmap pages

2015-04-29T13:37:52+00:00

Extend the -m option so that the number of mmap pages for AUX area
tracing can be specified by adding a comma followed by the number of
pages.

Signed-off-by: Adrian Hunter 
Acked-by: Jiri Olsa 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1428594864-29309-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo