On s390 using linux-next the test case:
87: perf record offcpu profiling tests
fails. The root cause is this command
# ./perf record --off-cpu -e dummy -- ./perf bench sched messaging -l 10
# Running 'sched/messaging' benchmark:
# 20 sender and receiver processes per group
# 10 groups == 400 processes run
Total time: 0.231 [sec]
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.077 MB perf.data (401 samples) ]
#
It does not generate 800+ sample entries, on s390 usually around
40[1-9], sometimes a few more, but never more than 450. The higher the
number of CPUs the lower the number of samples.
Looking at function chain:
bench_sched_messaging()
+--> group()
the senders and receiver threads are created. The senders and receivers
call function ready() which writes one bytes and wait for a reply using
poll system() call.
As context switches are counted, the function ready() will trigger a
context switch when no input data is available after the write system
call. The write system call does not trigger context switches when the
data size is small. And writing 1000 bytes (10 iterations with
100 bytes) is not much and certainly won't block.
The 400+ context switch on s390 occur when the some receiver/sender
threads call ready() and wait for the response from function
bench_sched_messaging() being kicked off.
Lower the number of expected context switches to 400 to succeed on s390.
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20231106091627.2022530-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use perf version to detect whether BPF skeletons were enabled in a
build rather than a failing perf record.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Patrice Duroux <patrice.duroux@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230914211948.814999-6-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Running shellcheck on record_offcpu.sh throws below warning:
In tests/shell/record_offcpu.sh line 13:
trap - exit term int
^--^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
^--^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
^-^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
In tests/shell/record_offcpu.sh line 20:
trap trap_cleanup exit term int
^--^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
^--^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
^-^ SC3049 (warning): In POSIX sh, using lower/mixed case for signal names is undefined.
In tests/shell/record_offcpu.sh line 25:
if [ `id -u` != 0 ]
^-----^ SC2046 (warning): Quote this to prevent word splitting.
Fixed the warnings by:
- Capitalize signals(INT, TERM, EXIT) to avoid mixed/lower case naming of
signals.
- Adding quotes to avoid word splitting.
Result from shellcheck after patch changes:
$ shellcheck -S warning record_offcpu.sh
$
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230709182800.53002-4-atrajeev@linux.vnet.ibm.com
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This reverts commit a980755beb.
We need to better polish building with BPF skels, so revert back to
making it an experimental feature that has to be explicitely enabled
using BUILD_BPF_SKEL=1.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It's not 2&>1, the correct is 2>&1
Fixes: ade1d0307b ("perf offcpu: Update offcpu test for child process")
Signed-off-by: Patrice Duroux <patrice.duroux@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230303193058.21274-1-patrice.duroux@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
BPF skeleton support is now key to a number of perf features. Rather
than making it so that BPF support must be enabled for the build, make
this the default and error if the build lacks a clang and libbpf that
are sufficient. To avoid the error and build without BPF skeletons the
NO_BPF_SKEL=1 flag can be used. Add a build-options flag to 'perf
version' to enable detection of the BPF skeleton support and use this
in the offcpu shell test.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pavithra Gurushankar <gpavithrasha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The latest version of grep claims the egrep is now obsolete so the build
now contains warnings that look like:
egrep: warning: egrep is obsolescent; using grep -E
fix this up by moving the related file to use "grep -E" instead.
sed -i "s/egrep/grep -E/g" `grep egrep -rwl tools/perf`
Here are the steps to install the latest grep:
wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz
tar xf grep-3.8.tar.gz
cd grep-3.8 && ./configure && make
sudo make install
export PATH=/usr/local/bin:$PATH
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1668762999-9297-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Record off-cpu data with perf bench sched messaging workload and count
the number of offcpu-time events. Also update the test script not to
run next tests if failed already and revise the error messages.
$ sudo ./perf test offcpu -v
88: perf record offcpu profiling tests :
--- start ---
test child forked, pid 344780
Checking off-cpu privilege
Basic off-cpu test
Basic off-cpu test [Success]
Child task off-cpu test
Child task off-cpu test [Success]
test child finished with 0
---- end ----
perf record offcpu profiling tests: Ok
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220811185456.194721-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
$ sudo ./perf test -v offcpu
88: perf record offcpu profiling tests :
--- start ---
test child forked, pid 685966
Basic off-cpu test
Basic off-cpu test [Success]
test child finished with 0
---- end ----
perf record offcpu profiling tests: Ok
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220518224725.742882-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
