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Perf's BPF prologue generator unconditionally fetches 8 bytes for
function parameters, which causes problems on big endian machines. Thomas
gives a detailed analysis for this problem:
http://lkml.kernel.org/r/968ebda5-abe4-8830-8d69-49f62529d151@linux.vnet.ibm.com
---- 8< ----
I investigated perf test BPF for s390x and have a question regarding
the 38.3 subtest (bpf-prologue test) which fails on s390x.
When I turn on trace_printk in tests/bpf-script-test-prologue.c
I see this output in /sys/kernel/debug/tracing/trace:
[root@s8360047 perf]# cat /sys/kernel/debug/tracing/trace
perf-30229 [000] d..2 170161.535791: : f_mode 2001d00000000 offset:0 orig:0
perf-30229 [000] d..2 170161.535809: : f_mode 6001f00000000 offset:0 orig:0
perf-30229 [000] d..2 170161.535815: : f_mode 6001f00000000 offset:1 orig:0
perf-30229 [000] d..2 170161.535819: : f_mode 2001d00000000 offset:1 orig:0
perf-30229 [000] d..2 170161.535822: : f_mode 2001d00000000 offset:2 orig:1
perf-30229 [000] d..2 170161.535825: : f_mode 6001f00000000 offset:2 orig:1
perf-30229 [000] d..2 170161.535828: : f_mode 6001f00000000 offset:3 orig:1
perf-30229 [000] d..2 170161.535832: : f_mode 2001d00000000 offset:3 orig:1
perf-30229 [000] d..2 170161.535835: : f_mode 2001d00000000 offset:4 orig:0
perf-30229 [000] d..2 170161.535841: : f_mode 6001f00000000 offset:4 orig:0
[...]
There are 3 parameters the eBPF program tests/bpf-script-test-prologue.c
accesses: f_mode (member of struct file at offset 140) offset and orig. They
are parameters of the lseek() system call triggered in this test case in
function llseek_loop().
What is really strange is the value of f_mode. It is an 8 byte value, whereas
in the probe event it is defined as a 4 byte value. The lower 4 bytes are all
zero and do not belong to member f_mode. The correct value should be 2001d for
read-only and 6001f for read-write open mode.
Here is the output of the 'perf test -vv bpf' trace:
Try to find probe point from debuginfo.
Matched function: null_lseek [2d9310d]
Probe point found: null_lseek+0
Searching 'file' variable in context.
Converting variable file into trace event.
converting f_mode in file
f_mode type is unsigned int.
Opening /sys/kernel/debug/tracing//README write=0
Searching 'offset' variable in context.
Converting variable offset into trace event.
offset type is long long int.
Searching 'orig' variable in context.
Converting variable orig into trace event.
orig type is int.
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: p:perf_bpf_probe/func _text+8794224 f_mode=+140(%r2):x32
---- 8< ----
This patch parses the type of each argument and converts data from memory to
expected type.
Now the test runs successfully on 4.13.0-rc5:
[root@s8360046 perf]# ./perf test bpf
38: BPF filter :
38.1: Basic BPF filtering : Ok
38.2: BPF pinning : Ok
38.3: BPF prologue generation : Ok
38.4: BPF relocation checker : Ok
[root@s8360046 perf]#
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170815092159.31912-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If that is the case, or if the required lib is not present, e.g.
elfutils-devel in Fedora systems, then just skip the tests requiring
DWARF analysis.
Before:
# rpm -e elfutils-devel
# perf test ping vfs_getname
60: Use vfs_getname probe to get syscall args filenames : FAILED!
61: probe libc's inet_pton & backtrace it with ping : Ok
62: Check open filename arg using perf trace + vfs_getname: FAILED!
63: Add vfs_getname probe to get syscall args filenames : FAILED!
#
After:
# perf test vfs_getname
60: Use vfs_getname probe to get syscall args filenames : Skip
62: Check open filename arg using perf trace + vfs_getname: Skip
63: Add vfs_getname probe to get syscall args filenames : Skip
#
Then, reinstalling elfutils-devel, rebuilding the tool and running
again:
# perf test vfs_getname
60: Use vfs_getname probe to get syscall args filenames : Ok
62: Check open filename arg using perf trace + vfs_getname: Ok
63: Add vfs_getname probe to get syscall args filenames : Ok
#
Reported-by: Kim Phillips <kim.phillips@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d67tvn401fxrwr97pu5ihfb1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a library function that checks if 'perf probe' is built into the
tool being tested, skipping tests that need it.
Testing it on a system after removing the library needed to build
'probe' as a perf subcommand:
# perf test ping vfs_getname
59: Use vfs_getname probe to get syscall args filenames : Skip
60: probe libc's inet_pton & backtrace it with ping : Skip
61: Check open filename arg using perf trace + vfs_getname: Skip
62: Add vfs_getname probe to get syscall args filenames : Skip
# perf probe
perf: 'probe' is not a perf-command. See 'perf --help'.
#
Now reinstalling elfutils-libelf-devel on this Fedora 26 system to
rebuild perf and then retest this:
# perf test ping vfs_getname
60: Use vfs_getname probe to get syscall args filenames : Ok
61: probe libc's inet_pton & backtrace it with ping : Ok
62: Check open filename arg using perf trace + vfs_getname: Ok
63: Add vfs_getname probe to get syscall args filenames : Ok
#
Reported-by: Kim Phillips <kim.phillips@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ctdck2gzsskqhjzu3ebb62zm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Installs a probe on libc's inet_pton function, that will use uprobes,
then use 'perf trace' on a ping to localhost asking for just one packet
with the a backtrace 3 levels deep, check that it is what we expect.
This needs no debuginfo package, all is done using the libc ELF symtab
and the CFI info in the binaries.
Testing it:
# perf test ping
61: probe libc's inet_pton & backtrace it with ping : Ok
In verbose mode:
# perf test -v ping
61: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 1007
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.058 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.058/0.058/0.058/0.000 ms
0.000 probe_libc:inet_pton:(7f75fce12a20))
__GI___inet_pton (/usr/lib64/libc-2.24.so)
getaddrinfo (/usr/lib64/libc-2.24.so)
_init (/usr/bin/ping)
test child finished with 0
---- end ----
probe libc's inet_pton & backtrace it with ping: Ok
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-idrntt4nbg15aafu8hjmv7sk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Uses the 'perf test shell' library to add probe:vfs_getname to the
system then use it with 'perf trace' using 'touch' to write to a temp
file, then checks that that was captured by the vfs_getname was used by
'perf trace', that already handles "probe:vfs_getname" if present, and
used in the "open" syscall "filename" argument beautifier.
Testing it:
# perf test "trace + vfs_getname"
61: Check open filename arg using perf trace + vfs_getname: Ok
#
# perf test -v "trace + vfs_getname"
61: Check open filename arg using perf trace + vfs_getname:
--- start ---
test child forked, pid 30846
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=result->name:string)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_getname -aR sleep 1
2.237 ( 0.012 ms): touch/30855 open(filename: /tmp/temporary_file.kmoWQ, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: IRUGO|IWUGO) = 3
test child finished with 0
---- end ----
Check open filename arg using perf trace + vfs_getname: Ok
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-j02nobfvvn9c7yrphdsnbqx0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This test uses the 'perf test shell' library to add probe:vfs_getname to the
system then use it with 'perf record' using 'touch' to write to a temp file,
then checks that that was captured by the vfs_getname probe in the generated
perf.data file, with the temp file name as the pathname argument.
Using it:
# perf test "Use vfs_getname"
60: Use vfs_getname probe to get syscall args filenames: Ok
# perf test -v "Use vfs_getname"
60: Use vfs_getname probe to get syscall args filenames:
--- start ---
test child forked, pid 16414
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=result->name:string)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_getname -aR sleep 1
Recording open file:
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.022 MB /tmp/vaca.perf.data.QZsn7 (13 samples) ]
Looking at perf.data file for vfs_getname records for the file we touched:
touch 16421 [002] 1255152.879561: probe:vfs_getname: (ffffffffa626e608) pathname="/tmp/vaca.l10SL"
test child finished with 0
---- end ----
Use vfs_getname probe to get syscall args filenames: Ok
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-t555fnhbcbxnukltk23dqxur@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
First perf shell test:
# perf test vfs_getname
60: Add vfs_getname probe to get syscall args filenames: Ok
#
In verbose mode:
# perf test -v vfs_getname
60: Add vfs_getname probe to get syscall args filenames:
--- start ---
test child forked, pid 19146
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=result->name:string)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_getname -aR sleep 1
test child finished with 0
---- end ----
Add vfs_getname probe to get syscall args filenames: Ok
#
And if the vmlinux file is not found:
# mv ../build/v4.12.0-rc6+/vmlinux ../build/v4.12.0-rc6+/vmlinux.hidden
# perf test vfs_getname
60: Add vfs_getname probe to get syscall args filenames: Skip
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-8f3n22c1yn516ev30s603ow2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before:
# perf test Synth
39: Synthesize thread map : Ok
41: Synthesize cpu map : Ok
42: Synthesize stat config : Ok
43: Synthesize stat : Ok
44: Synthesize stat round : Ok
45: Synthesize attr update : Ok
# perf test list Synth
#
After:
# perf test Synth
39: Synthesize thread map : Ok
41: Synthesize cpu map : Ok
42: Synthesize stat config : Ok
43: Synthesize stat : Ok
44: Synthesize stat round : Ok
45: Synthesize attr update : Ok
# perf test list Synth
39: Synthesize thread map
41: Synthesize cpu map
42: Synthesize stat config
43: Synthesize stat
44: Synthesize stat round
45: Synthesize attr update
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-v95tqqzuwawsmds3zn2mosje@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To allow testing by directly using perf tools in scripts, checking that
the effects on the system are the ones expected and that the output
produced is as well the desired one.
For instance, adding a probe at a well known location with 'perf probe',
then checking that the results from using that probe to record are the
desired ones, etc.
The next csets will introduce tests using this new testing
infrastructure.
The scripts should return 0 for Ok, 1 for FAIL and 2 for SKIP.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-swbpn7amrjqffh83lsr39s9p@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before:
# perf test Synth
39: Synthesize thread map : Ok
41: Synthesize cpu map : Ok
42: Synthesize stat config : Ok
43: Synthesize stat : Ok
44: Synthesize stat round : Ok
45: Synthesize attr update : Ok
#
# perf test list Synth
1: Synthesize thread map
2: Synthesize cpu map
3: Synthesize stat config
4: Synthesize stat
5: Synthesize stat round
6: Synthesize attr update
#
After:
# perf test Synth
39: Synthesize thread map : Ok
41: Synthesize cpu map : Ok
42: Synthesize stat config : Ok
43: Synthesize stat : Ok
44: Synthesize stat round : Ok
45: Synthesize attr update : Ok
#
# perf test list Synth
39: Synthesize thread map
41: Synthesize cpu map
42: Synthesize stat config
43: Synthesize stat
44: Synthesize stat round
45: Synthesize attr update
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-pjhuhkphs7o3tkbqrukfv6bz@git.kernel.org
Fixes: e8210cefb7 ("perf tests: Introduce iterator function for tests")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It can return NULL, in which case we should bail out and remove the
directory created with mkdtemp(), which is stored in the "__tempdir"
variable, not in "tempdir".
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 8e5dc84835 ("perf test: Add a test case for SDT event")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch adds platform dependency into the test case 15
(perf_event_attr). It is based on a suggestion from Jiri Olsa.
Add a new optional attribute named 'arch' in the [config] section of the
test case file. It is a comma separated list of architecture names this
test can be executed on. For example:
arch = x86_64,alpha,ppc
If this attribute is missing the test is executed on any platform. This
does not break existing behavior.
The values listed for this attribute should be identical to uname -m
output.
If the list starts with an exclamation mark (!) the comparison is
inverted, for example for
arch = !s390x,ppc
the test is not executed on s390x or ppc platforms. The exclamation
mark must be at the beginnning of the list.
Here is an example debug output:
[root@s35lp76]# fgrep arch tests/attr/test-stat-C2
arch = x86_64,alpha,ppc
[root@s35lp76]# PERF_TEST_ATTR=/tmp /usr/bin/python2 ./tests/attr.py \
-d ./tests/attr/ -p ./perf -vvvvv -t test-stat-C1
provides the following output:
running './tests/attr//test-stat-C1'
test limitation 'x86_64,alpha,ppc' <--- new
loading expected events
Event event:base-stat
fd = 1
group_fd = -1
.....
Here is the output when a test is skipped:
[root@s35lp76]# fgrep arch tests/attr/test-stat-C1
arch = !s390x
[root@s35lp76]# PERF_TEST_ATTR=/tmp /usr/bin/python2 ./tests/attr.py \
-d ./tests/attr/ -p ./perf -vvvvv -t test-stat-C1
provides the following output:
test limitation '!s390x' <--- new
skipped [s390x] './tests/attr//test-stat-C1' <--- new
The test is skipped with return code 0.
Suggested-and-Acked-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20170622073625.86762-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'if' keyword is a define that expands to complex code when
CONFIG_PROFILE_ALL_BRANCHES is selected, which causes a 'perf test LLVM'
failure like:
$ ./perf test LLVM
35: LLVM search and compile :
35.1: Basic BPF llvm compile : Ok
35.2: kbuild searching : Ok
35.3: Compile source for BPF prologue generation: FAILED!
35.4: Compile source for BPF relocation : Skip
The only affected test case is bpf-script-test-prologue.c
because it uses kernel headers and has 'if' inside.
This patch undefines 'if' to make it passes perf test.
More detailed analysis from a message in this thread, also by Wang:
The problem is caused by following relocation information:
$ readelf -a ./llvmsubtest3
...
[ 5] _ftrace_branch PROGBITS 0000000000000000 00000260
00000000000000a0 0000000000000000 WA 0 0 4
...
Relocation section '.relfunc=null_lseek file->f_mode offset orig' at
offset 0x490 contains 4 entries:
Offset Info Type Sym. Value Sym. Name
000000000038 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch
0000000000b0 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch
000000000128 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch
0000000001c0 000b00000001 unrecognized: 1 0000000000000000 _ftrace_branch
Relocation section '.rel_ftrace_branch' at offset 0x4d0 contains 8 entries:
Offset Info Type Sym. Value Sym. Name
000000000000 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n
000000000008 000100000001 unrecognized: 1 0000000000000015 .L.str
000000000028 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n
000000000030 000100000001 unrecognized: 1 0000000000000015 .L.str
000000000050 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n
000000000058 000100000001 unrecognized: 1 0000000000000015 .L.str
000000000078 000200000001 unrecognized: 1 0000000000000000 .L__func__.bpf_func__n
000000000080 000100000001 unrecognized: 1 0000000000000015 .L.str
...
So I think the failure is because you enabled CONFIG_PROFILE_ALL_BRANCHES.
I can reproduce your buggy result by selecting
CONFIG_PROFILE_ALL_BRANCHES in my kbuild:
$ ./perf test LLVM
35: LLVM search and compile :
35.1: Basic BPF llvm compile : Ok
35.2: kbuild searching : Ok
35.3: Compile source for BPF prologue generation: FAILED!
35.4: Compile source for BPF relocation : Skip
Simply undef CONFIG_PROFILE_ALL_BRANCHES in clang opts not working
because it is introduced by "#include <uapi/linux/fs.h>", which override
cmdline options. So I think the best way is to undefine 'if' inside BPF
script.
Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/20170620183203.2517-1-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since commit 18e7a45af9 ("perf/x86: Reject non sampling events with
precise_ip") returns -EINVAL for sys_perf_event_open() with an attribute
with (attr.precise_ip > 0 && attr.sample_period == 0), just like is done
in the routine used to probe the max precise level when no events were
passed to 'perf record' or 'perf top', i.e.:
perf_evsel__new_cycles()
perf_event_attr__set_max_precise_ip()
The x86 code, in x86_pmu_hw_config(), which is called all the way from
sys_perf_event_open() did, starting with the aforementioned commit:
/* There's no sense in having PEBS for non sampling events: */
if (!is_sampling_event(event))
return -EINVAL;
Which makes it fail for cycles:ppp, cycles:pp and cycles:p, always using
just the non precise cycles variant.
To make sure that this is the case, I tested it, before this patch,
with:
# perf probe -L x86_pmu_hw_config
<x86_pmu_hw_config@/home/acme/git/linux/arch/x86/events/core.c:0>
0 int x86_pmu_hw_config(struct perf_event *event)
1 {
2 if (event->attr.precise_ip) {
<SNIP>
17 if (event->attr.precise_ip > precise)
18 return -EOPNOTSUPP;
/* There's no sense in having PEBS for non sampling events: */
21 if (!is_sampling_event(event))
22 return -EINVAL;
}
<SNIP>
# perf probe x86_pmu_hw_config:22
Added new events:
probe:x86_pmu_hw_config (on x86_pmu_hw_config:22)
probe:x86_pmu_hw_config_1 (on x86_pmu_hw_config:22)
You can now use it in all perf tools, such as:
perf record -e probe:x86_pmu_hw_config_1 -aR sleep 1
# perf trace -e perf_event_open,probe:x86_pmu_hwconfig*/max-stack=16/ perf record usleep 1
0.000 ( 0.015 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ...
0.015 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
x86_pmu_hw_config ([kernel.kallsyms])
hsw_hw_config ([kernel.kallsyms])
x86_pmu_event_init ([kernel.kallsyms])
perf_try_init_event ([kernel.kallsyms])
perf_event_alloc ([kernel.kallsyms])
SYSC_perf_event_open ([kernel.kallsyms])
sys_perf_event_open ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
return_from_SYSCALL_64 ([kernel.kallsyms])
syscall (/usr/lib64/libc-2.24.so)
perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
perf_evsel__new_cycles (/home/acme/bin/perf)
perf_evlist__add_default (/home/acme/bin/perf)
cmd_record (/home/acme/bin/perf)
run_builtin (/home/acme/bin/perf)
handle_internal_command (/home/acme/bin/perf)
0.000 ( 0.021 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
0.023 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ...
0.025 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
x86_pmu_hw_config ([kernel.kallsyms])
hsw_hw_config ([kernel.kallsyms])
x86_pmu_event_init ([kernel.kallsyms])
perf_try_init_event ([kernel.kallsyms])
perf_event_alloc ([kernel.kallsyms])
SYSC_perf_event_open ([kernel.kallsyms])
sys_perf_event_open ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
return_from_SYSCALL_64 ([kernel.kallsyms])
syscall (/usr/lib64/libc-2.24.so)
perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
perf_evsel__new_cycles (/home/acme/bin/perf)
perf_evlist__add_default (/home/acme/bin/perf)
cmd_record (/home/acme/bin/perf)
run_builtin (/home/acme/bin/perf)
handle_internal_command (/home/acme/bin/perf)
0.023 ( 0.004 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
0.028 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1 ) ...
0.030 ( ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
x86_pmu_hw_config ([kernel.kallsyms])
hsw_hw_config ([kernel.kallsyms])
x86_pmu_event_init ([kernel.kallsyms])
perf_try_init_event ([kernel.kallsyms])
perf_event_alloc ([kernel.kallsyms])
SYSC_perf_event_open ([kernel.kallsyms])
sys_perf_event_open ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
return_from_SYSCALL_64 ([kernel.kallsyms])
syscall (/usr/lib64/libc-2.24.so)
perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
perf_evsel__new_cycles (/home/acme/bin/perf)
perf_evlist__add_default (/home/acme/bin/perf)
cmd_record (/home/acme/bin/perf)
run_builtin (/home/acme/bin/perf)
handle_internal_command (/home/acme/bin/perf)
0.028 ( 0.004 ms): perf/4150 ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
41.018 ( 0.012 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8b5dd0, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
41.065 ( 0.011 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
41.080 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
41.103 ( 0.010 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
41.115 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
41.122 ( 0.004 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
41.128 ( 0.008 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]
#
I.e. that return -EINVAL in x86_pmu_hw_config() is hit three times.
So fix it by just setting attr.sample_period
Now, after this patch:
# perf trace --max-stack=2 -e perf_event_open,probe:x86_pmu_hw_config* perf record usleep 1
[ perf record: Woken up 1 times to write data ]
0.000 ( 0.017 ms): perf/8469 perf_event_open(attr_uptr: 0x7ffe36c27d10, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 4
syscall (/usr/lib64/libc-2.24.so)
perf_event_open_cloexec_flag (/home/acme/bin/perf)
0.050 ( 0.031 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
syscall (/usr/lib64/libc-2.24.so)
perf_evlist__config (/home/acme/bin/perf)
0.092 ( 0.040 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
syscall (/usr/lib64/libc-2.24.so)
perf_evlist__config (/home/acme/bin/perf)
0.143 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, cpu: -1, group_fd: -1 ) = 4
syscall (/usr/lib64/libc-2.24.so)
perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
0.161 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
syscall (/usr/lib64/libc-2.24.so)
perf_evsel__open (/home/acme/bin/perf)
0.171 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
syscall (/usr/lib64/libc-2.24.so)
perf_evsel__open (/home/acme/bin/perf)
0.180 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
syscall (/usr/lib64/libc-2.24.so)
perf_evsel__open (/home/acme/bin/perf)
0.190 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
syscall (/usr/lib64/libc-2.24.so)
perf_evsel__open (/home/acme/bin/perf)
[ perf record: Captured and wrote 0.017 MB perf.data (7 samples) ]
#
The probe one called from perf_event_attr__set_max_precise_ip() works
the first time, with attr.precise_ip = 3, wit hthe next ones being the
per cpu ones for the cycles:ppp event.
And here is the text from a report and alternative proposed patch by
Thomas-Mich Richter:
---
On s390 the counter and sampling facility do not support a precise IP
skid level and sometimes returns EOPNOTSUPP when structure member
precise_ip in struct perf_event_attr is not set to zero.
On s390 commnd 'perf record -- true' fails with error EOPNOTSUPP. This
happens only when no events are specified on command line.
The functions called are
...
--> perf_evlist__add_default
--> perf_evsel__new_cycles
--> perf_event_attr__set_max_precise_ip
The last function determines the value of structure member precise_ip by
invoking the perf_event_open() system call and checking the return code.
The first successful open is the value for precise_ip.
However the value is determined without setting member sample_period and
indicates no sampling.
On s390 the counter facility and sampling facility are different. The
above procedure determines a precise_ip value of 3 using the counter
facility. Later it uses the sampling facility with a value of 3 and
fails with EOPNOTSUPP.
---
v2: Older compilers (e.g. gcc 4.4.7) don't support referencing members
of unnamed union members in the container struct initialization, so
move from:
struct perf_event_attr attr = {
...
.sample_period = 1,
};
to right after it as:
struct perf_event_attr attr = {
...
};
attr.sample_period = 1;
v3: We need to reset .sample_period to 0 to let the users of
perf_evsel__new_cycles() to properly setup attr.sample_period or
attr.sample_freq. Reported by Ingo Molnar.
Reported-and-Acked-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 18e7a45af9 ("perf/x86: Reject non sampling events with precise_ip")
Link: http://lkml.kernel.org/n/tip-yv6nnkl7tzqocrm0hl3x7vf1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The following tests are failing on powerpc:
# perf test break
18: Breakpoint overflow signal handler : FAILED!
19: Breakpoint overflow sampling : FAILED!
The powerpc kenel so far does not have support to even create
instruction breakpoints using the perf event interface, so those tests
fail early in the config phase.
I added a '->is_supported()' callback to test struct to be able to
disable specific tests. It seems better than putting ifdefs directly to
the test array.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170601205450.GA398@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As it is going away from util.h, where it is not needed.
This is mostly for things like MAXPATHLEN, MAX() and MIN(), these later
two probably should go away in favor of its kernel sources replacements.
Link: http://lkml.kernel.org/n/tip-z1666f3fl3fqobxvjr5o2r39@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
