To work like strace and dereference syscall pointer args we need to
insert probes (or tracepoints) right after we copy those bytes from
userspace.
Since we're formatting the syscall args at raw_syscalls:sys_enter time,
we need to have a formatter that just stores the position where, later,
when we get the probe:vfs_getname, we can insert the pointer contents.
Now, if a probe:vfs_getname with this format is in place:
# perf probe -l
probe:vfs_getname (on getname_flags:72@/home/git/linux/fs/namei.c with pathname)
That was, in this case, put in place with:
# perf probe 'vfs_getname=getname_flags:72 pathname=filename:string'
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=filename:string)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_getname -aR sleep 1
#
Then 'perf trace' will notice that and do the pointer -> contents
expansion:
# trace -e open touch /tmp/bla
0.165 (0.010 ms): touch/17752 open(filename: /etc/ld.so.cache, flags: CLOEXEC) = 3
0.195 (0.011 ms): touch/17752 open(filename: /lib64/libc.so.6, flags: CLOEXEC) = 3
0.512 (0.012 ms): touch/17752 open(filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
0.582 (0.012 ms): touch/17752 open(filename: /tmp/bla, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: 438) = 3
#
Roughly equivalent to strace's output:
# strace -rT -e open touch /tmp/bla
0.000000 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 <0.000039>
0.000317 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 <0.000102>
0.001461 open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3 <0.000072>
0.000405 open("/tmp/bla", O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666) = 3 <0.000055>
0.000641 +++ exited with 0 +++
#
Now we need to either look for at all syscalls that are marked as
pointers and have some well known names ("filename", "pathname", etc)
and set the arg formatter to the one used for the "open" syscall in this
patch.
This implementation works for syscalls with just a string being copied
from userspace, for matching syscalls with more than one string being
copied via the same probe/trace point (vfs_getname) we need to extend
the vfs_getname probe spec to include the pointer too, but there are
some problems with that in 'perf probe' or the kernel kprobes code, need
to investigate before considering supporting multiple strings per
syscall.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Milian Wolff <mail@milianw.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-xvuwx6nuj8cf389kf9s2ue2s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- Force period term to overload global settings, i.e. previously this
command line:
$ perf record -e 'cpu/instructions,period=20000/',cycles -c 1000 sleep 1
would result in both events having a period equal to 1000, with the fix we
get something saner:
$ perf evlist -v | grep period
cpu/instructions,period=20000/: ... { sample_period, sample_freq }: 20000, ...
cycles: ... { sample_period, sample_freq }: 1000 ...
$
(Jiri Olsa)
Infrastructure changes:
- Use the dummy software event with freq=0 in the twatch.py python
binding example, to avoid disabling nohz. (Arnaldo Carvalho de Melo)
- Add some missing constants to the python binding. (Arnaldo Carvalho de Melo)
- Fix mismatched declarations for elf_getphdrnum, that happens
only in the corner case where this function is not found on
the system. (Arnaldo Carvalho de Melo)
- Add build test for having ending double slash. (Jiri Olsa)
- Introduce callgraph_set for callgraph option. (Kan Liang)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pawel Moll reported build issue for having extra slash (/) at the end of
the prefix variable.
$ make prefix=/usr/local/
CC tests/attr.o
tests/attr.c: In function ‘test__attr’:
tests/attr.c:168:50: error: expected ‘)’ before ‘;’ token
snprintf(path_perf, PATH_MAX, "%s/perf", BINDIR);
^
tests/attr.c:176:1: error: expected ‘;’ before ‘}’ token
}
^
tests/attr.c:176:1: error: control reaches end of non-void function [-Werror=return-type]
}
^
cc1: all warnings being treated as errors
Adding automated test case for this.
Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150727182417.GD20509@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently the command line option settings beats the per event period
settings:
With no global settings, we get per-event configuration:
$ perf record -e 'cpu/instructions,period=20000/' sleep 1
$ perf evlist -v
... { sample_period, sample_freq }: 20000 ...
With 'c' option period setup, we get 'c' option value:
$ perf record -e 'cpu/instructions,period=20000/' -c 1000 sleep 1
$ perf evlist -v
... { sample_period, sample_freq }: 1000 ...
This patch makes the per-event settings overload the global 'c' option
setup:
$ perf record -e 'cpu/instructions,period=20000/' -c 1000 sleep 1
$ perf evlist -v
... { sample_period, sample_freq }: 20000 ...
I think the making the per-event settings to overload any other config
makes more sense than current state. However it breaks the current
'period' term handling, which might cause some noise.. so let's see ;-).
Also fixing parse event tests with the new behaviour.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438162936-59698-3-git-send-email-kan.liang@intel.com
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The semantic associated in tools/perf/ with foo__delete(instance) is to
release all resources referenced by 'instance' members and then release
the memory for 'instance' itself.
The perf_session_env__delete() function isn't doing this, it just does
the first part, but the space used by 'instance' itself isn't freed, as
it is embedded in a larger structure, that will be freed at other stage.
For these cases we se foo__exit(), i.e. the usage is:
void foo__delete(foo)
{
if (foo) {
foo__exit(foo);
free(foo);
}
}
But when we have something like:
struct bar {
struct foo foo;
. . .
}
Then we can't really call foo__delete(&bar.foo), we must have this
instead:
void bar__exit(bar)
{
foo__exit(&bar.foo);
/* free other bar-> resources */
}
void bar__delete(bar)
{
if (bar) {
bar__exit(bar);
free(bar);
}
}
So just rename perf_session_env__delete() to perf_session_env__exit().
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-djbgpcfo5udqptx3q0flwtmk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When HAVE_ELF_GETPHDRNUM_SUPPORT is false we trip on this problem:
CC /tmp/build/perf/util/symbol-elf.o
util/symbol-elf.c:41:12: error: static declaration of ‘elf_getphdrnum’ follows non-static declaration
static int elf_getphdrnum(Elf *elf, size_t *dst)
^
In file included from util/symbol.h:19:0,
from util/symbol-elf.c:8:
/usr/include/libelf.h:206:12: note: previous declaration of ‘elf_getphdrnum’ was here
extern int elf_getphdrnum (Elf *__elf, size_t *__dst);
^
MKDIR /tmp/build/perf/bench/
/home/git/linux/tools/build/Makefile.build:68: recipe for target '/tmp/build/perf/util/symbol-elf.o' failed
make[3]: *** [/tmp/build/perf/util/symbol-elf.o] Error 1
Fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qcmekyfedmov4sxr0wahcikr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The python binding still doesn't provide symbol resolving facilities,
but the recent addition of the trace_event__register_resolver() function
made it add as a dependency the machine__resolve_kernel_addr() method,
that in turn drags all the symbol resolving code.
The problem:
[root@zoo ~]# perf test -v python
17: Try 'import perf' in python, checking link problems :
--- start ---
test child forked, pid 6853
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: machine__resolve_kernel_addr
test child finished with -1
---- end ----
Try 'import perf' in python, checking link problems: FAILED!
[root@zoo ~]#
Fix it by requiring this function to receive the resolver as a
parameter, just like pevent_register_function_resolver(), i.e. do
not explicitely refer to an object file not included in
tools/perf/util/python-ext-sources.
[root@zoo ~]# perf test python
17: Try 'import perf' in python, checking link problems : Ok
[root@zoo ~]#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: c3168b0db9 ("perf symbols: Provide libtraceevent callback to resolve kernel symbols")
Link: http://lkml.kernel.org/n/tip-vxlhh95v2em9zdbgj3jm7xi5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building with a prefix ending with a slash, for example:
$ make prefix=/usr/local/
one of the perf tests fail to compile due to BUILD_STR macro mishandling
bindir_SQ string containing with two slashes:
-DBINDIR="BUILD_STR(/usr/local//bin)"
with the following error:
CC tests/attr.o
tests/attr.c: In function ‘test__attr’:
tests/attr.c:168:50: error: expected ‘)’ before ‘;’ token
snprintf(path_perf, PATH_MAX, "%s/perf", BINDIR);
^
tests/attr.c:176:1: error: expected ‘;’ before ‘}’ token
}
^
tests/attr.c:176:1: error: control reaches end of non-void function [-Werror=return-type]
}
^
cc1: all warnings being treated as errors
This patch works around the problem by "cleaning" the bindir string
using make's abspath function.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1438092613-21014-1-git-send-email-pawel.moll@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The transaction length metrics in perf stat -T broke recently.
It would not match the metric correctly and always print K/sec.
This was caused by a incorrect update of the cycles_in_tx statistics.
Update the correct variable.
Also the check for zero division was reversed, which resulted in K/sec
being printed for no transactions. Fix this also up.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1438039491-22091-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We were storing a copy of kallsyms inside perf.data file so that we
could resolve kernel addresses to function (start, name, mod) tuples,
but that can be achieved using the symbol resolving routines we have
in symbols.c, and that are used elsewhere in tools/perf.
So, do just like 'perf trace' did and ask libtraceevent to use perf's
symbol resolution routines.
The next step is to just skip whatever kallsyms data is embedded in
older perf.data files and finally to stop storing kallsyms in the perf
data file, as the 20-bytes build-id stored in perf.data's header is
enough to find out the right symtab (be it ELF, kcore, kallsyms, etc) to
use.
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-d0rtb8tk9j72pz0ehw5fnp24@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that beautifiers wanting to resolve kernel function addresses to
names can do its work, now, for instance, the 'timer' tracepoints
beautifiers works with 'perf trace', see the "function=tick..." part:
# perf trace --event timer:hrtimer_start
<SNIP>
0.000 timer:hrtimer_start:hrtimer=0xffff88026f3101c0 function=tick_sched_timer/0x0 expires=52098339000000 softexpires=52098339000000)
0.003 timer:hrtimer_start:hrtimer=0xffff88026f3101c0 function=tick_sched_timer/0x0 expires=52098339000000 softexpires=52098339000000)
<SNIP>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-n4i0hxpbl1tnleiqkok47fw2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Allow filtering out of perf's PID via 'perf record --exclude-perf'. (Wang Nan)
- 'perf trace' now supports syscall groups, like strace, i.e:
$ trace -e file touch file
Will expand 'file' into multiple, file related, syscalls. More work needed to
add extra groups for other syscall groups, and also to complement what was
added for the 'file' group, included as a proof of concept. (Arnaldo Carvalho de Melo)
- Add lock_pi stresser to 'perf bench futex', to test the kernel code
related to FUTEX_(UN)LOCK_PI. (Davidlohr Bueso)
User visible fixes:
- Apply --filter to all events in a glob matching, not just the last one. (Wang Nan)
Documentation changes:
- Document setting '-e pmu/period=N/' in the 'perf record' man page. (Kan Liang)
Infrastructure changes:
- 'perf probe' code simplifications and movements to separate files. (Masami Hiramatsu)
- Fix makefile generation under 'dash'. (Sergei Trofimovich)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allows a way of measuring low level kernel implementation of FUTEX_LOCK_PI and
FUTEX_UNLOCK_PI.
The program comes in two flavors:
(i) single futex (default), all threads contend on the same uaddr. For the
sake of the benchmark, we call into kernel space even when the lock is
uncontended. The kernel will set it to TID, any waters that come in and
contend for the pi futex will be handled respectively by the kernel.
(ii) -M option for multiple futexes, each thread deals with its own futex. This
is a trivial scenario and only measures kernel handling of 0->TID transition.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1436259353.12255.78.camel@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch allows 'perf record' to exclude events issued by perf itself
by '--exclude-perf' option.
Before this patch, when doing something like:
# perf record -a -e syscalls:sys_enter_write <cmd>
One could easily get result like this:
# /tmp/perf report --stdio
...
# Overhead Command Shared Object Symbol
# ........ ....... .................. ....................
#
99.99% perf libpthread-2.18.so [.] __write_nocancel
0.01% ls libc-2.18.so [.] write
0.01% sshd libc-2.18.so [.] write
...
Where most events are generated by perf itself.
A shell trick can be done to filter perf itself out:
# cat << EOF > ./tmp
> #!/bin/sh
> exec perf record -e ... --filter="common_pid != \$\$" -a sleep 10
> EOF
# chmod a+x ./tmp
# ./tmp
However, doing so is user unfriendly.
This patch extracts evsel iteration framework introduced by patch 'perf
record: Apply filter to all events in a glob matching' into
foreach_evsel_in_last_glob(), and makes exclude_perf() function append
new filter expression to each evsel selected by a '-e' selector.
To avoid losing filters if user pass '--filter' after '--exclude-perf',
this patch uses perf_evsel__append_filter() in both case, instead of
perf_evsel__set_filter() which removes old filter. As a side effect, now
it is possible to use multiple '--filter' option for one selector. They
are combinded with '&&'.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1436513770-8896-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is an old problem in perf's filter applying which first posted at
Sep. 2014 at https://lkml.org/lkml/2014/9/9/944 that, if passing
multiple events in a glob matching expression in cmdline then add
'--filter' after them, the filter will be applied on only the last one.
For example:
# dd if=/dev/zero of=/dev/null &
[1] 464
# perf record -a -e 'syscalls:sys_*_read' --filter 'common_pid != 464' sleep 0.1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.239 MB perf.data (2094 samples) ]
# perf report --stdio | tee
...
# Samples: 2K of event 'syscalls:sys_enter_read'
# Event count (approx.): 2092
...
# Samples: 2 of event 'syscalls:sys_exit_read'
# Event count (approx.): 2
...
In this example, filter only applied on 'syscalls:sys_exit_read', and
there's no way to set filter for ''syscalls:sys_enter_read'.
This patch adds a 'cmdline_group_boundary' for 'struct evsel', and
apply filter on all events between two boundary marks.
After applying this patch:
# perf record -a -e 'syscalls:sys_*_read' --filter 'common_pid != 464' sleep 0.1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.031 MB perf.data (3 samples) ]
# perf report --stdio | tee
...
# Samples: 1 of event 'syscalls:sys_enter_read'
# Event count (approx.): 1
...
# Samples: 2 of event 'syscalls:sys_exit_read'
# Event count (approx.): 2
...
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reported-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1436513770-8896-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
