Commit 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
causes test case 14 "Parse sched tracepoints fields" to fail on s390.
This test succeeds on x86.
In fact this test now fails on all architectures with type char
treated as type unsigned char.
The root cause is the signed-ness of character arrays in the
tracepoints sched_switch for structure members prev_comm and
next_comm.
On s390 the output of
[root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/\
sched/sched_switch/format
name: sched_switch
ID: 287
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
...
field:char prev_comm[16]; offset:8; size:16; signed:0;
...
field:char next_comm[16]; offset:40; size:16; signed:0;
reveals the character arrays prev_comm and next_comm are per
default unsigned char and have values in the range of 0..255.
On x86 both fields are signed as this output shows:
[root@f29]# cat /sys/kernel/debug/tracing/events/sched/\
sched_switch/format
name: sched_switch
ID: 287
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
...
field:char prev_comm[16]; offset:8; size:16; signed:1;
...
field:char next_comm[16]; offset:40; size:16; signed:1;
and the character arrays prev_comm and next_comm are per
default signed char and have values in the range of -1..127.
The implementation of type char is architecture specific.
Since the character arrays in both tracepoints
sched_switch and sched_wakeup should contain ascii characters,
simply omit the check for signedness in the test case.
Output before:
[root@m35lp76 perf]# ./perf test -F 14
14: Parse sched tracepoints fields :
--- start ---
sched:sched_switch: "prev_comm" signedness(0) is wrong, should be 1
sched:sched_switch: "next_comm" signedness(0) is wrong, should be 1
sched:sched_wakeup: "comm" signedness(0) is wrong, should be 1
---- end ----
14: Parse sched tracepoints fields : FAILED!
[root@m35lp76 perf]#
Output after:
[root@m35lp76 perf]# ./perf test -Fv 14
14: Parse sched tracepoints fields :
--- start ---
---- end ----
Parse sched tracepoints fields: Ok
[root@m35lp76 perf]#
Fixes: 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
Signed-off-by: Thomas Richter <[email protected]>
---
tools/perf/tests/evsel-tp-sched.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
index 5cbba70bcdd0..ea7acf403727 100644
--- a/tools/perf/tests/evsel-tp-sched.c
+++ b/tools/perf/tests/evsel-tp-sched.c
@@ -43,7 +43,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
return -1;
}
- if (perf_evsel__test_field(evsel, "prev_comm", 16, true))
+ if (perf_evsel__test_field(evsel, "prev_comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "prev_pid", 4, true))
@@ -55,7 +55,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
if (perf_evsel__test_field(evsel, "prev_state", sizeof(long), true))
ret = -1;
- if (perf_evsel__test_field(evsel, "next_comm", 16, true))
+ if (perf_evsel__test_field(evsel, "next_comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "next_pid", 4, true))
@@ -73,7 +73,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
return -1;
}
- if (perf_evsel__test_field(evsel, "comm", 16, true))
+ if (perf_evsel__test_field(evsel, "comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "pid", 4, true))
--
2.19.1
Em Tue, Feb 19, 2019 at 04:36:39PM +0100, Thomas Richter escreveu:
> Commit 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
> causes test case 14 "Parse sched tracepoints fields" to fail on s390.
> This test succeeds on x86.
> In fact this test now fails on all architectures with type char
> treated as type unsigned char.
>
> The root cause is the signed-ness of character arrays in the
> tracepoints sched_switch for structure members prev_comm and
> next_comm.
>
> On s390 the output of
> [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/\
> sched/sched_switch/format
> name: sched_switch
> ID: 287
> format:
> field:unsigned short common_type; offset:0; size:2; signed:0;
> ...
> field:char prev_comm[16]; offset:8; size:16; signed:0;
> ...
> field:char next_comm[16]; offset:40; size:16; signed:0;
>
> reveals the character arrays prev_comm and next_comm are per
> default unsigned char and have values in the range of 0..255.
>
> On x86 both fields are signed as this output shows:
> [root@f29]# cat /sys/kernel/debug/tracing/events/sched/\
> sched_switch/format
> name: sched_switch
> ID: 287
> format:
> field:unsigned short common_type; offset:0; size:2; signed:0;
> ...
> field:char prev_comm[16]; offset:8; size:16; signed:1;
> ...
> field:char next_comm[16]; offset:40; size:16; signed:1;
>
> and the character arrays prev_comm and next_comm are per
> default signed char and have values in the range of -1..127.
> The implementation of type char is architecture specific.
>
> Since the character arrays in both tracepoints
> sched_switch and sched_wakeup should contain ascii characters,
> simply omit the check for signedness in the test case.
>
> Output before:
> [root@m35lp76 perf]# ./perf test -F 14
> 14: Parse sched tracepoints fields :
> --- start ---
> sched:sched_switch: "prev_comm" signedness(0) is wrong, should be 1
> sched:sched_switch: "next_comm" signedness(0) is wrong, should be 1
> sched:sched_wakeup: "comm" signedness(0) is wrong, should be 1
> ---- end ----
Please indent command output by two chars to avoid things like lines
starting with '---' to break scripts that expect that to be the marker
for the end of the commit log message as below...
> 14: Parse sched tracepoints fields : FAILED!
> [root@m35lp76 perf]#
>
> Output after:
> [root@m35lp76 perf]# ./perf test -Fv 14
> 14: Parse sched tracepoints fields :
> --- start ---
> ---- end ----
> Parse sched tracepoints fields: Ok
> [root@m35lp76 perf]#
>
> Fixes: 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
>
> Signed-off-by: Thomas Richter <[email protected]>
> ---
... here ^^^
I'm fixing this up now.
- Arnaldo
> tools/perf/tests/evsel-tp-sched.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
> index 5cbba70bcdd0..ea7acf403727 100644
> --- a/tools/perf/tests/evsel-tp-sched.c
> +++ b/tools/perf/tests/evsel-tp-sched.c
> @@ -43,7 +43,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
> return -1;
> }
>
> - if (perf_evsel__test_field(evsel, "prev_comm", 16, true))
> + if (perf_evsel__test_field(evsel, "prev_comm", 16, false))
> ret = -1;
>
> if (perf_evsel__test_field(evsel, "prev_pid", 4, true))
> @@ -55,7 +55,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
> if (perf_evsel__test_field(evsel, "prev_state", sizeof(long), true))
> ret = -1;
>
> - if (perf_evsel__test_field(evsel, "next_comm", 16, true))
> + if (perf_evsel__test_field(evsel, "next_comm", 16, false))
> ret = -1;
>
> if (perf_evsel__test_field(evsel, "next_pid", 4, true))
> @@ -73,7 +73,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
> return -1;
> }
>
> - if (perf_evsel__test_field(evsel, "comm", 16, true))
> + if (perf_evsel__test_field(evsel, "comm", 16, false))
> ret = -1;
>
> if (perf_evsel__test_field(evsel, "pid", 4, true))
> --
> 2.19.1
--
- Arnaldo
Commit-ID: 03d309711d687460d1345de8a0363f45b1c8cd11
Gitweb: https://git.kernel.org/tip/03d309711d687460d1345de8a0363f45b1c8cd11
Author: Thomas Richter <[email protected]>
AuthorDate: Tue, 19 Feb 2019 16:36:39 +0100
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 19 Feb 2019 13:43:29 -0300
perf test: Fix failure of 'evsel-tp-sched' test on s390
Commit 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
causes test case 14 "Parse sched tracepoints fields" to fail on s390.
This test succeeds on x86.
In fact this test now fails on all architectures with type char treated
as type unsigned char.
The root cause is the signed-ness of character arrays in the tracepoints
sched_switch for structure members prev_comm and next_comm.
On s390 the output of:
[root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/sched/sched_switch/format
name: sched_switch
ID: 287
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
...
field:char prev_comm[16]; offset:8; size:16; signed:0;
...
field:char next_comm[16]; offset:40; size:16; signed:0;
reveals the character arrays prev_comm and next_comm are per
default unsigned char and have values in the range of 0..255.
On x86 both fields are signed as this output shows:
[root@f29]# cat /sys/kernel/debug/tracing/events/sched/sched_switch/format
name: sched_switch
ID: 287
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
...
field:char prev_comm[16]; offset:8; size:16; signed:1;
...
field:char next_comm[16]; offset:40; size:16; signed:1;
and the character arrays prev_comm and next_comm are per default signed
char and have values in the range of -1..127. The implementation of
type char is architecture specific.
Since the character arrays in both tracepoints sched_switch and
sched_wakeup should contain ascii characters, simply omit the check for
signedness in the test case.
Output before:
[root@m35lp76 perf]# ./perf test -F 14
14: Parse sched tracepoints fields :
--- start ---
sched:sched_switch: "prev_comm" signedness(0) is wrong, should be 1
sched:sched_switch: "next_comm" signedness(0) is wrong, should be 1
sched:sched_wakeup: "comm" signedness(0) is wrong, should be 1
---- end ----
14: Parse sched tracepoints fields : FAILED!
[root@m35lp76 perf]#
Output after:
[root@m35lp76 perf]# ./perf test -Fv 14
14: Parse sched tracepoints fields :
--- start ---
---- end ----
Parse sched tracepoints fields: Ok
[root@m35lp76 perf]#
Fixes: 489338a717a0 ("perf tests evsel-tp-sched: Fix bitwise operator")
Signed-off-by: Thomas Richter <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/tests/evsel-tp-sched.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
index 5cbba70bcdd0..ea7acf403727 100644
--- a/tools/perf/tests/evsel-tp-sched.c
+++ b/tools/perf/tests/evsel-tp-sched.c
@@ -43,7 +43,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
return -1;
}
- if (perf_evsel__test_field(evsel, "prev_comm", 16, true))
+ if (perf_evsel__test_field(evsel, "prev_comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "prev_pid", 4, true))
@@ -55,7 +55,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
if (perf_evsel__test_field(evsel, "prev_state", sizeof(long), true))
ret = -1;
- if (perf_evsel__test_field(evsel, "next_comm", 16, true))
+ if (perf_evsel__test_field(evsel, "next_comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "next_pid", 4, true))
@@ -73,7 +73,7 @@ int test__perf_evsel__tp_sched_test(struct test *test __maybe_unused, int subtes
return -1;
}
- if (perf_evsel__test_field(evsel, "comm", 16, true))
+ if (perf_evsel__test_field(evsel, "comm", 16, false))
ret = -1;
if (perf_evsel__test_field(evsel, "pid", 4, true))