<feed xmlns='http://www.w3.org/2005/Atom'>
<title>blackbird-op-linux/tools/perf/util, branch master</title>
<subtitle>Blackbird™ Linux sources for OpenPOWER</subtitle>
<id>https://git.raptorcs.com/git/blackbird-op-linux/atom?h=master</id>
<link rel='self' href='https://git.raptorcs.com/git/blackbird-op-linux/atom?h=master'/>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/'/>
<updated>2020-02-14T13:06:00+00:00</updated>
<entry>
<title>perf llvm: Fix script used to obtain kernel make directives to work with new kbuild</title>
<updated>2020-02-14T13:06:00+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-02-14T12:34:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=62765941155e487b351a72479078bd6fec973563'/>
<id>urn:sha1:62765941155e487b351a72479078bd6fec973563</id>
<content type='text'>
Before this patch:

  # ./perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : FAILED!
  39.3: Compile source for BPF prologue generation          : Skip
  39.4: Compile source for BPF relocation                   : Skip
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : FAILED!
  41.4: BPF relocation checker                              : Skip
  #

Using 'perf test -v' for these tests shows that it is not finding
uapi/linux/fs.h, which ends up being because we don't setup the right header
path. Fix it.

After this patch:

  # perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : Ok
  39.3: Compile source for BPF prologue generation          : Ok
  39.4: Compile source for BPF relocation                   : Ok
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : Ok
  41.4: BPF relocation checker                              : Ok
  #

Longer description:

In llvm-utils.c we use some techniques to obtain the kbuild make
directives and that recently stopped working as now 'ar' gets called and
expects to find the dummy.o used to echo these variables:

  $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)

Add the $(CC) line to satisfy that, making sure this works with all
kernels, i.e. preserving the temp directory and files in it used for
this technique we can see that it works everywhere:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:42 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:42 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #
  # cat /tmp/tmp.qgaFHgxjZ4/Makefile
  obj-y := dummy.o
  $(obj)/%.o: $(src)/%.c
          @echo -n "$(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)"
          $(CC) -c -o $@ $&lt;
  #

Then build with an old kernel Makefile:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
  -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 8
  drwx------.  2 root root  100 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:43 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #

And a new one:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  # make -s -C /lib/modules/5.6.0-rc1+/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
   -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 16
  drwx------.  2 root root  160 Feb 14 09:44 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:44 ..
  -rw-r--r--.  1 root root  158 Feb 14 09:44 built-in.a
  -rw-r--r--.  1 root root  149 Feb 14 09:44 .built-in.a.cmd
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:44 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  -rw-r--r--.  1 root root    0 Feb 14 09:44 modules.order
  #

Reported-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Tested-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: Zefan Li &lt;lizefan@huawei.com&gt;
Link: https://www.spinics.net/lists/linux-perf-users/msg10600.html
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf maps: Move kmap::kmaps setup to maps__insert()</title>
<updated>2020-02-11T19:41:49+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-02-10T14:32:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=484214f49bd0948d716832a94e4737ca4dd02c16'/>
<id>urn:sha1:484214f49bd0948d716832a94e4737ca4dd02c16</id>
<content type='text'>
So the kmaps pointer setup is centralized and we do not need to update
it in all those places (2 current places and few more missing) after
calling maps__insert().

Reported-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Tested-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200210143218.24948-5-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf maps: Fix map__clone() for struct kmap</title>
<updated>2020-02-11T19:41:49+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-02-10T14:32:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=7ce66139a99ce57caaf47b64afed5cb6ed02c5ed'/>
<id>urn:sha1:7ce66139a99ce57caaf47b64afed5cb6ed02c5ed</id>
<content type='text'>
The map__clone() function can be called on kernel maps as well, so it
needs to duplicate the whole kmap data.

Reported-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Tested-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200210143218.24948-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf maps: Mark ksymbol DSOs with kernel type</title>
<updated>2020-02-11T19:41:49+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@redhat.com</email>
</author>
<published>2020-02-10T20:08:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=4a4eb6154d67f7766cc7eb74e9f1db424073e832'/>
<id>urn:sha1:4a4eb6154d67f7766cc7eb74e9f1db424073e832</id>
<content type='text'>
We add ksymbol map into machine-&gt;kmaps, so it needs to be created as
'struct kmap', which is dependent on its dso having kernel type.

Reported-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Tested-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200210200847.GA36715@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf maps: Mark module DSOs with kernel type</title>
<updated>2020-02-11T19:41:49+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-02-10T14:32:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=02213cec64bbef66d7ad9ddc3b7c47236da64343'/>
<id>urn:sha1:02213cec64bbef66d7ad9ddc3b7c47236da64343</id>
<content type='text'>
We add kernel module map into machine-&gt;kmaps, so it needs to be created
as 'struct kmap', which is dependent on its dso having kernel type.

Reported-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200210143218.24948-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf symbols: Convert symbol__is_idle() to use strlist</title>
<updated>2020-02-10T19:30:51+00:00</updated>
<author>
<name>Kim Phillips</name>
<email>kim.phillips@amd.com</email>
</author>
<published>2020-02-10T16:31:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=bc5f15be2c814ca1ff6bb4e62d5b275a8c88cbb1'/>
<id>urn:sha1:bc5f15be2c814ca1ff6bb4e62d5b275a8c88cbb1</id>
<content type='text'>
Use the more optimized strlist implementation to do the idle function
lookup.

Signed-off-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200210163147.25358-1-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf symbols: Update the list of kernel idle symbols</title>
<updated>2020-02-10T19:30:13+00:00</updated>
<author>
<name>Kim Phillips</name>
<email>kim.phillips@amd.com</email>
</author>
<published>2020-02-07T23:06:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=0e71459afcbbf69e92a65085c45515d3f3f02c31'/>
<id>urn:sha1:0e71459afcbbf69e92a65085c45515d3f3f02c31</id>
<content type='text'>
The "acpi_idle_do_entry", "acpi_processor_ffh_cstate_enter", and
"idle_cpu" symbols appear in 'perf top' output, at least on AMD systems.

Add them to perf's idle_symbols list, so they don't dominate 'perf top'
output.

Signed-off-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200207230613.26709-2-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf stat: Don't report a null stalled cycles per insn metric</title>
<updated>2020-02-10T19:30:09+00:00</updated>
<author>
<name>Kim Phillips</name>
<email>kim.phillips@amd.com</email>
</author>
<published>2020-02-07T23:06:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=80cc7bb6c104d733bff60ddda09f19139c61507c'/>
<id>urn:sha1:80cc7bb6c104d733bff60ddda09f19139c61507c</id>
<content type='text'>
For data collected on machines with front end stalled cycles supported,
such as found on modern AMD CPU families, commit 146540fb545b ("perf
stat: Always separate stalled cycles per insn") introduces a new line in
CSV output with a leading comma that upsets some automated scripts.
Scripts have to use "-e ex_ret_instr" to work around this issue, after
upgrading to a version of perf with that commit.

We could add "if (have_frontend_stalled &amp;&amp; !config-&gt;csv_sep)" to the not
(total &amp;&amp; avg) else clause, to emphasize that CSV users are usually
scripts, and are written to do only what is needed, i.e., they wouldn't
typically invoke "perf stat" without specifying an explicit event list.

But - let alone CSV output - why should users now tolerate a constant
0-reporting extra line in regular terminal output?:

BEFORE:

$ sudo perf stat --all-cpus -einstructions,cycles -- sleep 1

 Performance counter stats for 'system wide':

       181,110,981      instructions              #    0.58  insn per cycle
                                                  #    0.00  stalled cycles per insn
       309,876,469      cycles

       1.002202582 seconds time elapsed

The user would not like to see the now permanent:

  "0.00  stalled cycles per insn"

line fixture, as it gives no useful information.

So this patch removes the printing of the zeroed stalled cycles line
altogether, almost reverting the very original commit fb4605ba47e7
("perf stat: Check for frontend stalled for metrics"), which seems like
it was written to normalize --metric-only column output of common Intel
machines at the time: modern Intel machines have ceased to support the
genericised frontend stalled metrics AFAICT.

AFTER:

$ sudo perf stat --all-cpus -einstructions,cycles -- sleep 1

 Performance counter stats for 'system wide':

       244,071,432      instructions              #    0.69  insn per cycle
       355,353,490      cycles

       1.001862516 seconds time elapsed

Output behaviour when stalled cycles is indeed measured is not affected
(BEFORE == AFTER):

$ sudo perf stat --all-cpus -einstructions,cycles,stalled-cycles-frontend -- sleep 1

 Performance counter stats for 'system wide':

       247,227,799      instructions              #    0.63  insn per cycle
                                                  #    0.26  stalled cycles per insn
       394,745,636      cycles
        63,194,485      stalled-cycles-frontend   #   16.01% frontend cycles idle

       1.002079770 seconds time elapsed

Fixes: 146540fb545b ("perf stat: Always separate stalled cycles per insn")
Signed-off-by: Kim Phillips &lt;kim.phillips@amd.com&gt;
Acked-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200207230613.26709-1-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf maps: Add missing unlock to maps__insert() error case</title>
<updated>2020-01-31T08:40:50+00:00</updated>
<author>
<name>Cengiz Can</name>
<email>cengiz@kernel.wtf</email>
</author>
<published>2020-01-20T14:15:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=85fc95d75970ee7dd8e01904e7fb1197c275ba6b'/>
<id>urn:sha1:85fc95d75970ee7dd8e01904e7fb1197c275ba6b</id>
<content type='text'>
`tools/perf/util/map.c` has a function named `maps__insert` that
acquires a write lock if its in multithread context.

Even though this lock is released when function successfully completes,
there's a branch that is executed when `maps_by_name == NULL` that
returns from this function without releasing the write lock.

Added an `up_write` to release the lock when this happens.

Fixes: a7c2b572e217 ("perf map_groups: Auto sort maps by name, if needed")
Signed-off-by: Cengiz Can &lt;cengiz@kernel.wtf&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lore.kernel.org/lkml/20200120141553.23934-1-cengiz@kernel.wtf
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf probe: Add ustring support for perf probe command</title>
<updated>2020-01-31T08:33:58+00:00</updated>
<author>
<name>Thomas Richter</name>
<email>tmricht@linux.ibm.com</email>
</author>
<published>2020-01-20T13:20:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=1873f1547dde65c687de143938581347a9312207'/>
<id>urn:sha1:1873f1547dde65c687de143938581347a9312207</id>
<content type='text'>
Kernel commit 88903c464321 ("tracing/probe: Add ustring type for user-space string")
adds support for user-space strings when type 'ustring' is specified.

Here is an example using sysfs command line interface
for kprobes:

Function to probe:
  struct filename *
  getname_flags(const char __user *filename, int flags, int *empty)

Setup:
  # cd /sys/kernel/debug/tracing/
  # echo 'p:tmr1 getname_flags +0(%r2):ustring' &gt; kprobe_events
  # cat events/kprobes/tmr1/format | fgrep print
  print fmt: "(%lx) arg1=\"%s\"", REC-&gt;__probe_ip, REC-&gt;arg1
  # echo 1 &gt; events/kprobes/tmr1/enable
  # touch /tmp/111
  # echo 0 &gt; events/kprobes/tmr1/enable
  # cat trace|fgrep /tmp/111
  touch-5846  [005] d..2 255520.717960: tmr1:\
	  (getname_flags+0x0/0x400) arg1="/tmp/111"

Doing the same with the perf tool fails.
Using type 'string' succeeds:
 # perf probe "vfs_getname=getname_flags:72 pathname=filename:string"
 Added new event:
   probe:vfs_getname (on getname_flags:72 with pathname=filename:string)
   ....
 # perf probe -d probe:vfs_getname
 Removed event: probe:vfs_getname

However using type 'ustring' fails (output before):
 # perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring"
 Failed to write event: Invalid argument
   Error: Failed to add events.
 #

Fix this by adding type 'ustring' in function
convert_variable_type().

Using ustring succeeds (output after):
 # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring"
 Added new event:
   probe:vfs_getname (on getname_flags:72 with pathname=filename:ustring)

 You can now use it in all perf tools, such as:

	perf record -e probe:vfs_getname -aR sleep 1

 #

Note: This issue also exists on x86, it is not s390 specific.

Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: sumanthk@linux.ibm.com
Link: http://lore.kernel.org/lkml/20200120132011.64698-2-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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