Version 2:
As suggested by Ian Rogers make perf_event_attribute member
exclude_hv more robust and accept value 0 or 1 to handle more
test cases which might fail on s390 virtual machine z/VM.
This test case fails on s390 virtual machine z/VM which has no PMU support
when the perf tool is built with LIBPFM4=1.
Using make LIBPFM4=1 builds the perf tool with support for libpfm
event notation. The command line flag --pfm-events is valid:
# ./perf record --pfm-events cycles -- true
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (2 samples) ]
#
However the command 'perf test -Fv 17' fails on s390 z/VM virtual machine
with LIBPFM4=1:
# perf test -Fv 17
17: Setup struct perf_event_attr :
--- start ---
.....
running './tests/attr/test-record-group2'
unsupp './tests/attr/test-record-group2'
running './tests/attr/test-record-pfm-period'
expected exclude_hv=0, got 1
FAILED './tests/attr/test-record-pfm-period' - match failure
---- end ----
Setup struct perf_event_attr: FAILED!
When --pfm-event system is not supported, the test returns unsupported
and continues. Here is an example using a virtual machine on x86 and
Fedora 34:
[root@f33 perf]# perf test -Fv 17
17: Setup struct perf_event_attr :
--- start ---
.....
running './tests/attr/test-record-group2'
unsupp './tests/attr/test-record-group2'
running './tests/attr/test-record-pfm-period'
unsupp './tests/attr/test-record-pfm-period'
....
The issue is file ./tests/attr/test-record-pfm-period
which requires perf event attribute member exclude_hv to be zero.
This is not the case on s390 where the value of exclude_hv is one when
executing on a z/VM virtual machine without PMU hardware support.
Fix this by allowing value exlucde_hv to be zero or one.
Output before:
# /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \
test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match
matching [event:base-record]
match: [event:base-record] matches []
FAILED './tests/attr//test-record-pfm-period' - match failure
#
Output after:
# /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \
test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match
matching [event:base-record]
match: [event:base-record] matches ['event-1-0-6', 'event-1-0-5']
matched
Background:
Using libpfm library ends up in this function call sequence
pfm_get_perf_event_encoding()
+-- pfm_get_os_event_encoding()
+-- pfmlib_perf_event_encode()
is called when no hardware specific PMU unit can be detected
as in the s390 z/VM virtual machine case. This uses the
"perf_events generic PMU" data structure which sets exclude_hv
to 1 per default. Using this PMU that test case always fails.
That is the reason why exclude_hv attribute setting varies.
Signed-off-by: Thomas Richter <[email protected]>
Suggested-by: Ian Rogers <[email protected]>
---
tools/perf/tests/attr/base-record | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/tests/attr/base-record b/tools/perf/tests/attr/base-record
index 4a7b8deef3fd..8c10955eff93 100644
--- a/tools/perf/tests/attr/base-record
+++ b/tools/perf/tests/attr/base-record
@@ -16,7 +16,7 @@ pinned=0
exclusive=0
exclude_user=0
exclude_kernel=0|1
-exclude_hv=0
+exclude_hv=0|1
exclude_idle=0
mmap=1
comm=1
--
2.31.1
On Fri, May 28, 2021 at 2:11 AM Thomas Richter <[email protected]> wrote:
>
> Version 2:
> As suggested by Ian Rogers make perf_event_attribute member
> exclude_hv more robust and accept value 0 or 1 to handle more
> test cases which might fail on s390 virtual machine z/VM.
>
> This test case fails on s390 virtual machine z/VM which has no PMU support
> when the perf tool is built with LIBPFM4=1.
>
> Using make LIBPFM4=1 builds the perf tool with support for libpfm
> event notation. The command line flag --pfm-events is valid:
> # ./perf record --pfm-events cycles -- true
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.001 MB perf.data (2 samples) ]
> #
>
> However the command 'perf test -Fv 17' fails on s390 z/VM virtual machine
> with LIBPFM4=1:
> # perf test -Fv 17
> 17: Setup struct perf_event_attr :
> --- start ---
> .....
> running './tests/attr/test-record-group2'
> unsupp './tests/attr/test-record-group2'
> running './tests/attr/test-record-pfm-period'
> expected exclude_hv=0, got 1
> FAILED './tests/attr/test-record-pfm-period' - match failure
> ---- end ----
> Setup struct perf_event_attr: FAILED!
>
> When --pfm-event system is not supported, the test returns unsupported
> and continues. Here is an example using a virtual machine on x86 and
> Fedora 34:
> [root@f33 perf]# perf test -Fv 17
> 17: Setup struct perf_event_attr :
> --- start ---
> .....
> running './tests/attr/test-record-group2'
> unsupp './tests/attr/test-record-group2'
> running './tests/attr/test-record-pfm-period'
> unsupp './tests/attr/test-record-pfm-period'
> ....
>
> The issue is file ./tests/attr/test-record-pfm-period
> which requires perf event attribute member exclude_hv to be zero.
> This is not the case on s390 where the value of exclude_hv is one when
> executing on a z/VM virtual machine without PMU hardware support.
>
> Fix this by allowing value exlucde_hv to be zero or one.
>
> Output before:
> # /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \
> test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match
> matching [event:base-record]
> match: [event:base-record] matches []
> FAILED './tests/attr//test-record-pfm-period' - match failure
> #
>
> Output after:
> # /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \
> test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match
> matching [event:base-record]
> match: [event:base-record] matches ['event-1-0-6', 'event-1-0-5']
> matched
>
> Background:
> Using libpfm library ends up in this function call sequence
>
> pfm_get_perf_event_encoding()
> +-- pfm_get_os_event_encoding()
> +-- pfmlib_perf_event_encode()
>
> is called when no hardware specific PMU unit can be detected
> as in the s390 z/VM virtual machine case. This uses the
> "perf_events generic PMU" data structure which sets exclude_hv
> to 1 per default. Using this PMU that test case always fails.
>
> That is the reason why exclude_hv attribute setting varies.
>
> Signed-off-by: Thomas Richter <[email protected]>
> Suggested-by: Ian Rogers <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Tested on x86 with and without hypervisor and test still passes. This
would be expected as the change is making a flag more permissive. As
we don't care about this flag in existing tests I believe there's no
impact to this change other than fixing the tests on s390.
Thanks,
Ian
> ---
> tools/perf/tests/attr/base-record | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/tests/attr/base-record b/tools/perf/tests/attr/base-record
> index 4a7b8deef3fd..8c10955eff93 100644
> --- a/tools/perf/tests/attr/base-record
> +++ b/tools/perf/tests/attr/base-record
> @@ -16,7 +16,7 @@ pinned=0
> exclusive=0
> exclude_user=0
> exclude_kernel=0|1
> -exclude_hv=0
> +exclude_hv=0|1
> exclude_idle=0
> mmap=1
> comm=1
> --
> 2.31.1
>