kernel/tools/perf/tests/shell/lock_contention.sh, branch linux-rolling-stable

perf test: Fix lock contention test

2025-11-24T09:37:38Z

[ Upstream commit 3c723f449723db2dc2b75b7efe03c2a76e4c09f0 ] Couple of independent fixes: 1. Wire in SIGSEGV handler that terminates the test with a failure code. 2. Use "--lock-cgroup" instead of "-g"; "-g" was proposed but never merged. See commit 4d1792d0a2564caf ("perf lock contention: Add --lock-cgroup option") 3. Call cleanup() on every normal exit so trap_cleanup() doesn't mistake it for an unexpected signal and emit a false-negative "Unexpected signal in main" message. Before patch: # ./perf test -vv "lock contention" 85: kernel lock contention analysis test: --- start --- test child forked, pid 610711 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Unexpected signal in test_aggr_cgroup ---- end(0) ---- 85: kernel lock contention analysis test : Ok After patch: # ./perf test -vv "lock contention" 85: kernel lock contention analysis test: --- start --- test child forked, pid 602637 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Testing perf lock contention --type-filter (w/ spinlock) Testing perf lock contention --lock-filter (w/ tasklist_lock) Testing perf lock contention --callstack-filter (w/ unix_stream) [Skip] Could not find 'unix_stream' Testing perf lock contention --callstack-filter with task aggregation [Skip] Could not find 'unix_stream' Testing perf lock contention --cgroup-filter Testing perf lock contention CSV output ---- end(0) ---- 85: kernel lock contention analysis test : Ok Reviewed-by: Ian Rogers Signed-off-by: Ravi Bangoria Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ananth Narayan Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Cc: Santosh Shukla Cc: Tycho Andersen Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf test shell lock_contention: Extra debug diagnostics

2025-11-24T09:37:38Z

[ Upstream commit 8b93f8933d37591d17c59fd71b18fc61966d9515 ] In test_record_concurrent, as stderr is sent to /dev/null, error messages are hidden. Change this to gather the error messages and dump them on failure. Some minor sh->bash changes to add some more diagnostics in trap_cleanup. Reviewed-by: James Clark Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Blake Jones Cc: Chun-Tse Shao Cc: Collin Funk Cc: Howard Chu Cc: Ingo Molnar Cc: Jan Polensky Cc: Jiri Olsa Cc: Kan Liang Cc: Li Huafei Cc: Mark Rutland Cc: Nam Cao Cc: Peter Zijlstra Cc: Steinar H. Gunderson Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20250821163820.1132977-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Stable-dep-of: 3c723f449723 ("perf test: Fix lock contention test") Signed-off-by: Sasha Levin

perf test: Ensure lock contention using pipe mode

2025-07-30T20:38:53Z

The 'kernel lock contention analysis test' requires reliable triggering of lock contention. On some systems, previous benchmark calls failed to generate sufficient contention due to low system activity or resource limits. This patch adds the -p (pipe) option to all calls of perf bench sched messaging, ensuring consistent lock contention without relying on socket-based communication. Suggested-by: Thomas Richter Signed-off-by: Jan Polensky Link: https://lore.kernel.org/r/20250725170801.3176678-1-japo@linux.ibm.com Signed-off-by: Namhyung Kim

perf test: Change all remaining #!/bin/sh to #!/bin/bash

2025-06-26T17:31:05Z

There are 43 instances of posix shell tests and 35 instances of bash. To give us a single consistent language for testing in, replace all #!/bin/sh to #!/bin/bash. Common sources that are included in both different shells will now work as expected. And we no longer have to fix up bashisms that appear to work when someone's system has sh symlinked to bash, but don't work on other systems that have both shells installed. Although we could have chosen sh, it's not backwards compatible so it wouldn't be possible to bulk convert without re-writing the existing bash tests. Choosing bash also gives us some nicer features including 'local' variable definitions and regexes in if statements that are already widely used in the tests. It's not expected that there are any users with only sh available due to the large number of bash tests that exist. Discussed in relation to running shellcheck here: https://lore.kernel.org/linux-perf-users/e3751a74be34bbf3781c4644f518702a7270220b.1749785642.git.collin.funk1@gmail.com/ Signed-off-by: James Clark Reviewed-by: Collin Funk Acked-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20250623-james-perf-bash-tests-v1-1-f572f54d4559@linaro.org Signed-off-by: Namhyung Kim

perf test: Speed up some tests using perf list

2024-10-17T16:55:58Z

On my system, perf list is very slow to print the whole events. I think there's a performance issue in SDT and uprobes event listing. I noticed this issue while running perf test on x86 but it takes long to check some CoreSight event which should be skipped quickly. Anyway, some test uses perf list to check whether the required event is available before running the test. The perf list command can take an argument to specify event class or (glob) pattern. But glob pattern is only to suppress output for unmatched ones after checking all events. In this case, specifying event class is better to reduce the number of events it checks and to avoid buggy subsystems entirely. No functional changes intended. Reviewed-by: James Clark Reviewed-by: Ian Rogers Cc: German Gomez Cc: Carsten Haitzler Cc: Leo Yan Link: https://lore.kernel.org/r/20241016065654.269994-1-namhyung@kernel.org Signed-off-by: Namhyung Kim

perf tests: Ignore shellcheck warning in lock_contention

2023-10-17T19:40:51Z

Running shellcheck on lock_contention.sh generates below warning In tests/shell/lock_contention.sh line 36: if [ `nproc` -lt 4 ]; then ^-----^ SC2046: Quote this to prevent word splitting. Here since nproc will generate a single word output and there is no possibility of word splitting, this warning can be ignored. Use exception for this with "disable" option in shellcheck. This warning is observed after commit: "commit 29441ab3a30a ("perf test lock_contention.sh: Skip test if not enough CPUs")" Fixes: 29441ab3a30a ("perf test lock_contention.sh: Skip test if not enough CPUs") Signed-off-by: Athira Rajeev Reviewed-by: Kajol Jain Acked-by: Namhyung Kim Cc: maddy@linux.ibm.com Cc: disgoel@linux.vnet.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20231013073021.99794-2-atrajeev@linux.vnet.ibm.com Signed-off-by: Namhyung Kim

perf test lock_contention.sh: Skip test if not enough CPUs

2023-09-21T18:55:13Z

Machines with less then 4 CPUs weren't consistently triggering lock events required for the test. Skip the test on those machines. The limit of 4 CPUs is set as it generates around 100 lock events for a test. Signed-off-by: Veronika Molnarova Acked-by: Michael Petlan Link: https://lore.kernel.org/r/20230919150419.23193-2-vmolnaro@redhat.com Signed-off-by: Namhyung Kim

perf test shell lock_contention: Add cgroup aggregation and filter tests

2023-09-12T20:32:00Z

Add cgroup aggregation and filter tests. $ sudo ./perf test -v contention 84: kernel lock contention analysis test : --- start --- test child forked, pid 222423 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Testing perf lock contention --type-filter (w/ spinlock) Testing perf lock contention --lock-filter (w/ tasklist_lock) Testing perf lock contention --callstack-filter (w/ unix_stream) Testing perf lock contention --callstack-filter with task aggregation Testing perf lock contention --cgroup-filter Testing perf lock contention CSV output test child finished with 0 ---- end ---- kernel lock contention analysis test: Ok Committer testing: [root@quaco ~]# uname -a Linux quaco 6.4.10-200.fc38.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Aug 11 12:20:29 UTC 2023 x86_64 GNU/Linux [root@quaco ~]# perf test -v contention 84: kernel lock contention analysis test : --- start --- test child forked, pid 452625 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Testing perf lock contention --type-filter (w/ spinlock) Testing perf lock contention --lock-filter (w/ tasklist_lock) Testing perf lock contention --callstack-filter (w/ unix_stream) Testing perf lock contention --callstack-filter with task aggregation Testing perf lock contention --cgroup-filter Testing perf lock contention CSV output test child finished with 0 ---- end ---- kernel lock contention analysis test: Ok [root@quaco ~]# Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Hao Luo Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230906174903.346486-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tests lock_contention: Fix shellcheck issue about quoting to avoid word splitting

2023-08-03T20:01:25Z

Running shellcheck on lock_contention.sh generates below warning: In tests/shell/lock_contention.sh line 24: if [ `id -u` != 0 ]; then ^-----^ SC2046 (warning): Quote this to prevent word splitting. In tests/shell/lock_contention.sh line 160: local type=$(head -1 "${result}" | awk '{ print $8 }' | sed -e 's/:.*//') ^--------^ SC3043 (warning): In POSIX sh, 'local' is undefined. ^--^ SC2155 (warning): Declare and assign separately to avoid masking return values. ^-- SC2046 (warning): Quote this to prevent word splitting. Fixed above warnings by: - Adding quotes to avoid word splitting. - Fixing shellcheck warnings for local usage, by prefixing function name to the variable. Signed-off-by: Kajol Jain Acked-by: Ian Rogers Cc: Disha Goel Cc: Jiri Olsa Cc: Madhavan Srinivasan Cc: Namhyung Kim Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20230709182800.53002-5-atrajeev@linux.vnet.ibm.com Signed-off-by: Athira Rajeev Signed-off-by: Arnaldo Carvalho de Melo

perf test: Test perf lock contention CSV output

2023-07-01T17:49:03Z

To verify CSV output, just check the number of separators (",") using the tr and wc commands like this. grep -v "^#" ${result} | tr -d -c | wc -c Now it expects 6 columns (and 5 separators) in the output, but it may be changed later so count the field in the header first and compare it to the actual output lines. $ cat ${result} # output: contended, total wait, max wait, avg wait, type, caller 1, 28787, 28787, 28787, spinlock, raw_spin_rq_lock_nested+0x1b The test looks like below now: $ sudo ./perf test -v contention 86: kernel lock contention analysis test : --- start --- test child forked, pid 2705822 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --type-filter (w/ spinlock) Testing perf lock contention --lock-filter (w/ tasklist_lock) Testing perf lock contention --callstack-filter (w/ unix_stream) Testing perf lock contention --callstack-filter with task aggregation Testing perf lock contention CSV output test child finished with 0 ---- end ---- kernel lock contention analysis test: Ok Acked-by: Ian Rogers Cc: Hao Luo Cc: Peter Zijlstra Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Ingo Molnar Cc: Song Liu Link: https://lore.kernel.org/r/20230628200141.2739587-5-namhyung@kernel.org Signed-off-by: Namhyung Kim