I have a workload where perf top scribbles over the stack and we SEGV.
What makes it interesting is that an snprintf is causing this.
The workload is a c++ gem that has method names over 3000 characters
long, but snprintf is designed to avoid overrunning buffers. So what
went wrong?
The problem is we assume snprintf returns the number of characters
written:
ret += repsep_snprintf(bf + ret, size - ret, "[%c] ", self->level);
...
ret += repsep_snprintf(bf + ret, size - ret, "%s", self->ms.sym->name);
Unfortunately this is not how snprintf works. snprintf returns the
number of characters that would have been written if there was enough
space. In the above case, if the first snprintf returns a value larger
than size, we pass a negative size into the second snprintf and happily
scribble over the stack. If you have 3000 character c++ methods thats a
lot of stack to trample.
This patch fixes repsep_snprintf by clamping the value at size - 1 which
is the maximum snprintf can write before adding the NULL terminator.
I get the sinking feeling that there are a lot of other uses of snprintf
that have this same bug, we should audit them all.
Cc: David Ahern <dsahern@gmail.com>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/20120307114249.44275ca3@kryten
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch fixes a buffer overrun bug in
tracepoint_id_to_path(). The bug manisfested itself as a memory
error reported by perf record. I ran into it with perf sched:
$ perf sched rec noploop 2 noploop for 2 seconds
[ perf record: Woken up 14 times to write data ]
[ perf record: Captured and wrote 42.701 MB perf.data (~1865622 samples) ]
Fatal: No memory to alloc tracepoints list
It turned out that tracepoint_id_to_path() was reading the
tracepoint id using read() but the buffer was not large enough
to include the \n terminator for id with 4 digits or more.
The patch fixes the problem by extending the buffer to a more
reasonable size covering all possible id length include \n
terminator. Note that atoll() stops at the first non digit
character, thus it is not necessary to clear the buffer between
each read.
Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: fweisbec@gmail.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/20120313155102.GA6465@quad
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Just fall back to resetting those fields, if set, warning the user that
that feature is not available.
If guest samples appear they will just be discarded because no struct
machine will be found and thus the event will be accounted as not
handled and dropped, see 0c09571.
Reported-by: Namhyung Kim <namhyung@gmail.com>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-vuwxig36mzprl5n7nzvnxxsh@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Setting perf_guest to true by default makes no sense because the perf
subcommands can not setup guest symbol information and thus not process
and guest samples. The only exception is perf-kvm which changes the
perf_guest value on its own. So change the default for perf_guest back
to false.
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1328893505-4115-3-git-send-email-joerg.roedel@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'perf probe' command allows kprobe to be inserted at any offset from
a function start, which results in adding kprobes to unintended
location. (example: perf probe do_fork+10000 is allowed even though
size of do_fork is ~904).
My previous patch https://lkml.org/lkml/2012/2/24/42 addressed the case
where DWARF info was available for the kernel. This patch fixes the
case where perf probe is used on a kernel without debuginfo available.
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F4C544D.1010909@linux.vnet.ibm.com
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1330111898-68071-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf probe command allows kprobe to be inserted at any offset from a
function start, which results in adding kprobes to unintended location.
Example: perf probe do_fork+10000 is allowed even though size of do_fork
is ~904.
This patch will ensure probe addition fails when the offset specified is
greater than size of the function.
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/4F473F33.4060409@linux.vnet.ibm.com
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On old kernels that don't support sample_id_all feature,
perf_evlist__id2evsel() returns NULL for non-sampling events.
This breaks perf top when multiple events are given on command line. Fix
it by using first evsel in the evlist. This will also prevent getting
the same (potential) problem in such new tool/ old kernel combo.
Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
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/1329702447-25045-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch fixes an issue where perf report shows nan% for certain
perf.data files. The below is from a report for a do_fork probe:
-nan% sshd [kernel.kallsyms] [k] do_fork
-nan% packagekitd [kernel.kallsyms] [k] do_fork
-nan% dbus-daemon [kernel.kallsyms] [k] do_fork
-nan% bash [kernel.kallsyms] [k] do_fork
A git bisect shows commit f3bda2c as the cause. However, looking back
through the git history, I saw commit 640c03c which seems to have
removed the required initialization for perf_sample->period. The problem
only started showing after commit f3bda2c. The below patch re-introduces
the initialization and it fixes the problem for me.
With the below patch, for the same perf.data:
73.08% bash [kernel.kallsyms] [k] do_fork
8.97% 11-dhclient [kernel.kallsyms] [k] do_fork
6.41% sshd [kernel.kallsyms] [k] do_fork
3.85% 20-chrony [kernel.kallsyms] [k] do_fork
2.56% sendmail [kernel.kallsyms] [k] do_fork
This patch applies over current linux-tip commit 9949284.
Problem introduced in:
$ git describe 640c03c
v2.6.37-rc3-83-g640c03c
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/20120203170113.5190.25558.stgit@localhost6.localdomain6
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 a1645ce12a
Author: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
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 <cjashfor@linux.vnet.ibm.com>
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/1328461865-6127-1-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The event_type record has a max length for the event name.
It's called MAX_EVENT_NAME.
The name may be truncated to fit the max length. But the header.size still
reflects the original name length. If that length is > MAX_EVENT_NAME, then the
header.size field is bogus. Fix this by using the length of the name after the
potential truncation.
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120120094912.GA4882@quad
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building on my Debian/mips system, util/util.c fails to build
because commit 1aed267173 (perf kvm: Do
guest-only counting by default) indirectly includes stdio.h before the
feature selection in util.h is done. This prevents _GNU_SOURCE in
util.h from enabling the declaration of getline(), from now second
inclusion of stdio.h, and the build is broken.
There is another breakage in util/evsel.c caused by include ordering,
but I didn't fully track down the commit that caused it.
The root cause of all this is an inconsistent definition of _GNU_SOURCE,
so I move the definition into the Makefile so that it is passed to all
invocations of the compiler and used uniformly for all system header
files. All other #define and #undef of _GNU_SOURCE are removed as they
cause conflicts with the definition passed to the compiler.
All the features.h definitions (_LARGEFILE64_SOURCE _FILE_OFFSET_BITS=64
and _GNU_SOURCE) are needed by the python glue code too, so they are
moved to BASIC_CFLAGS, and the misleading comments about BASIC_CFLAGS
are removed.
This gives me a clean build on x86_64 (fc12) and mips (Debian).
Cc: David Daney <david.daney@cavium.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1326836461-11952-1-git-send-email-ddaney.cavm@gmail.com
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The ctype.h include is not needed here and it breaks build on some systems (at
least 64bit Ubuntu 10.04) like below. Just get rid of it.
CC util/trace-event-info.o
cc1: warnings being treated as errors
util/trace-event-info.c: In function ‘record_file’:
util/trace-event-info.c:192: error: implicit declaration of function ‘pwrite’
util/trace-event-info.c:192: error: nested extern declaration of ‘pwrite’
make: *** [util/trace-event-info.o] Error 1
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1326035430-7621-1-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To restrict a counter to either host or guest mode this patch introduces
two new event modifiers: G and H.
With G the counter is configured in guest-only mode and with H in
host-only mode.
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/n/tip-or5aj3rghy9ngyg882z6kln9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make use of exclude_guest and exlude_host in perf-kvm to do only
guest-only counting by default.
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
[ committer note: Moved perf_{guest,host} & event_attr_init to util.c ]
[ so as not to drag more stuff to the python binding]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Stop using this python/OOP convention, doesn't really helps. Will do
more from time to time till we get it cleaned up in all of /perf.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-me4dyj6s5snh7jr8wb9gzt82@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Nowadays we do it per evsel, not per session (that may have multiple
evsels), so rename it to avoid confusion.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-azsgomr5h4dmaudoogw48w49@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'size' cannot be 0 because it was set to 8 on the above line in case
it was 0 and never changed.
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/1325000151-4463-1-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The current perf scripting facility only supports tracepoints. This
patch implements a generic perl handler to support other events than
tracepoints too.
This patch introduces a function process_event() that is called by perf
for each sample. The function is called with byte streams as arguments
containing information about the event, its attributes, the sample and
raw data. Perl's unpack() function can easily be used for byte decoding.
The following is the default implementation for process_event() that can
also be generated with perf script:
# Packed byte string args of process_event():
#
# $event: union perf_event util/event.h
# $attr: struct perf_event_attr linux/perf_event.h
# $sample: struct perf_sample util/event.h
# $raw_data: perf_sample->raw_data util/event.h
sub process_event
{
my ($event, $attr, $sample, $raw_data) = @_;
my @event = unpack("LSS", $event);
my @attr = unpack("LLQQQQQLLQQ", $attr);
my @sample = unpack("QLLQQQQQLL", $sample);
my @raw_data = unpack("C*", $raw_data);
use Data::Dumper;
print Dumper \@event, \@attr, \@sample, \@raw_data;
}
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323969824-9711-4-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch introduces the for_each_set_bit() macro and modifies feature
implementation to use it.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-8-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The features HEADER_TRACE_INFO and HEADER_BUILD_ID are handled
different when writing the feature section. All other features are
simply disabled on failure and writing the section goes on without
returning an error. There is no reason for these special cases. This
patch unifies handling of the features.
This should be ok since all features can be parsed independently.
Offset and size of a feature's block is stored in struct perf_file_
section right after the data block of perf.data (see perf_session__
write_header()). Thus, if a feature does not exist then other features
can be processed anyway.
Also moving special code for HEADER_BUILD_ID out to write_build_id().
v2:
* perf record throws an error now if buildids may not be generated,
which can be disabled with the --no-buildid option.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-6-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The default input file for perf report is not handled the same way as
perf record does it for its output file. This leads to unexpected
behavior of perf report, etc. E.g.:
# perf record -a -e cpu-cycles sleep 2 | perf report | cat
failed to open perf.data: No such file or directory (try 'perf record' first)
While perf record writes to a fifo, perf report expects perf.data to be
read. This patch changes this to accept fifos as input file.
Applies to the following commands:
perf annotate
perf buildid-list
perf evlist
perf kmem
perf lock
perf report
perf sched
perf script
perf timechart
Also fixes char const* -> const char* type declaration for filename
strings.
v2:
* Prevent potential null pointer access to input_name in
builtin-report.c. Needed due to removal of patch "perf report: Setup
browser if stdout is a pipe"
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-5-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If filename is NULL there is an out-of-bound access to struct
perf_session if it would be used with perf_session__open(). Shouldn't
actually happen in current implementation as filename is always !NULL.
Fixing this by always null-terminating filename.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-3-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A feature may be unknown if perf.data is created and parsed on different
perf tool versions. This should not stop the header to be processed,
instead continue processing it.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-2-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reducing duplication and line size by extending function names for
print and write from a single name.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-7-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now that we automatically point users at it, let's provide them some
guidance so that they hopefully don't just get mysterious EINVAL's
from the kernel.
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/1324301972-22740-4-git-send-email-nelhage@nelhage.com
Signed-off-by: Nelson Elhage <nelhage@nelhage.com>
[ committer note: Made it work after 50a682c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I get such truncated annotation results in 'perf top':
: Disassembly of section .text: ▒
: ▒
: ffffffff810966a8 <nr_iowait_cpu>: ▒
4.94 : ffffffff810966a8: movslq %edi,%rdi ▒
3.70 : ffffffff810966ab: mov $0x13700,%rax ▒
0.00 : ffffffff810966b2: add -0x7e32cb00(,%rdi,8),%rax ▒
8.64 : ffffffff810966ba: mov 0x7e0(%rax),%eax ▒
82.72 : ffffffff810966c0: cltq ▒
Note the missing 'retq' which is there in the original function:
ffffffff810966a8 <nr_iowait_cpu>:
ffffffff810966a8: 48 63 ff movslq %edi,%rdi
ffffffff810966ab: 48 c7 c0 00 37 01 00 mov $0x13700,%rax
ffffffff810966b2: 48 03 04 fd 00 35 cd add -0x7e32cb00(,%rdi,8),%rax
ffffffff810966b9: 81
ffffffff810966ba: 8b 80 e0 07 00 00 mov 0x7e0(%rax),%eax
ffffffff810966c0: 48 98 cltq
ffffffff810966c2: c3 retq
ffffffff810966c3 <this_cpu_load>:
I'm using a fairly recent binutils:
GNU objdump version 2.21.51.0.6-2.fc16 20110118
AFAICS the bug is simply that sym->end points to the last byte
of the symbol in question - while objdump's --stop-address
expects the last byte plus 1 to disassemble the full range.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111223130804.GA24305@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324578603-12762-3-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324578603-12762-2-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add new generic hw event: ref-cycles, which maps to
PERF_HW_COUNT_REF_CPUCYCLES:
$ perf stat -e ref-cycles ls
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-5-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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 <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323703017-6060-7-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
These files are part of PERF not GIT although they're come from there :)
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323784323-2150-1-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
After freeing each elements of the @values->value, we should free itself
too.
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/1323703017-6060-5-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The order of freeing comm_list and dso_list should be reversed.
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/1323703017-6060-4-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'path' variable is set on a upper line, don't need to do it again.
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/1323703017-6060-3-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On failure, perf_evlist__mmap_per_{cpu,thread} will try to munmap()
every map that doesn't have a NULL base. This will fail with EINVAL if
one of them has base == MAP_FAILED, clobbering errno, so that
perf_evlist__map will return EINVAL on any failure regardless of the
root cause.
Fix this by resetting failed maps to a NULL base.
Acked-by: Namhyung Kim <namhyung@gmail.com>
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/1324301972-22740-2-git-send-email-nelhage@nelhage.com
Signed-off-by: Nelson Elhage <nelhage@nelhage.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Memory in struct perf_sample is not fully initialized during parsing.
Depending on sampling data some parts may left unchanged. Zero out
struct perf_sample first to avoid access to uninitialized memory.
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1323966762-8574-2-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The problem is that when SAMPLE_PERIOD is not set, the kernel generates
a number of samples in proportion to an event's period. Number of these
samples may be too big and the kernel throttles all samples above a
defined limit.
E.g.: I want to trace when a process sleeps. I created a process which
sleeps for 1ms and for 4ms. perf got 100 events in both cases.
swapper 0 [000] 1141.371830: sched_stat_sleep: comm=foo pid=1801 delay=1386750 [ns]
swapper 0 [000] 1141.369444: sched_stat_sleep: comm=foo pid=1801 delay=4499585 [ns]
In the first case a kernel want to send 4499585 events and in the second
case it wants to send 1386750 events. perf-reports shows that process
sleeps in both places equal time.
Instead of this we can get only one sample with an attribute period. As
result we have less data transferring between kernel and user-space and
we avoid throttling of samples.
The patch "events: Don't divide events if it has field period" added a
kernel part of this functionality.
Acked-by: Arun Sharma <asharma@fb.com>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: devel@openvz.org
Link: http://lkml.kernel.org/r/1324391565-1369947-1-git-send-email-avagin@openvz.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It's the counterpart of perf_session__parse_sample.
v2: fixed mistakes found by David Ahern.
v3: s/data/sample/
s/perf_event__change_sample/perf_event__synthesize_sample
Reviewed-by: David Ahern <dsahern@gmail.com>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: devel@openvz.org
Link: http://lkml.kernel.org/r/1323266161-394927-3-git-send-email-avagin@openvz.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf_evsel.name may be not initialized
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arun Sharma <asharma@fb.com>
Cc: devel@openvz.org
Link: http://lkml.kernel.org/r/1322471015-107825-2-git-send-email-avagin@openvz.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A update is made to the sched:sched_switch event that adds some
logic to the first parameter of the __print_flags() that shows the
state of tasks. This change cause perf to fail parsing the flags.
A simple fix is needed to have the parser be able to process ops
within the argument.
Cc: stable@vger.kernel.org
Reported-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
So that tools like 'perf test' can print the events when in verbose
mode, for instance.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-xnovdqfi25nc48gy6604k7yp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
At first tools were required to do that, but while writing the python
bindings to simplify the API I made them auto-allocate when needed.
This just makes record, stat and top use that auto allocation,
simplifying them a bit.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-iokhcvkzzijr3keioubx8hlq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Anton Blanchard