kernel/tools/perf/bench/futex-wake-parallel.c, branch linux-rolling-stable

perf bench futex: Remove support for IMMUTABLE

2025-07-11T14:02:01Z

It has been decided to remove the support IMMUTABLE futex. perf bench was one of the eary users for testing purposes. Now that the API is removed before it could be used in an official release, remove the bits from perf, too. Remove Remove support for IMMUTABLE futex. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250710110011.384614-7-bigeasy@linutronix.de

tools/perf: Allow to select the number of hash buckets

2025-05-03T10:02:10Z

Add the -b/ --buckets argument to specify the number of hash buckets for the private futex hash. This is directly passed to prctl(PR_FUTEX_HASH, PR_FUTEX_HASH_SET_SLOTS, buckets, immutable) and must return without an error if specified. The `immutable' is 0 by default and can be set to 1 via the -I/ --immutable argument. The size of the private hash is verified with PR_FUTEX_HASH_GET_SLOTS. If PR_FUTEX_HASH_GET_SLOTS failed then it is assumed that an older kernel was used without the support and that the global hash is used. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250416162921.513656-20-bigeasy@linutronix.de

tools/perf: Fix timing issue with parallel threads in perf bench wake-up-parallel

2024-06-14T04:27:49Z

perf bench futex fails as below and hangs intermittently when attempted to run on on a powerpc system: ./perf bench futex wake-parallel Running 'futex/wake-parallel' benchmark: Run summary [PID 88588]: blocking on 640 threads (at [private] futex 0x10464b8c), 640 threads waking up 1 at a time. [Run 1]: Avg per-thread latency (waking 1/640 threads) in 0.1309 ms (+-53.27%) [Run 2]: Avg per-thread latency (waking 1/640 threads) in 0.0120 ms (+-31.16%) [Run 3]: Avg per-thread latency (waking 1/640 threads) in 0.1474 ms (+-92.47%) [Run 4]: Avg per-thread latency (waking 1/640 threads) in 0.2883 ms (+-67.75%) [Run 5]: Avg per-thread latency (waking 1/640 threads) in 0.4108 ms (+-39.60%) [Run 6]: Avg per-thread latency (waking 1/640 threads) in 0.7843 ms (+-78.98%) perf: couldn't wakeup all tasks (0/1) perf: couldn't wakeup all tasks (0/1) perf: couldn't wakeup all tasks (0/1) perf: couldn't wakeup all tasks (0/1) perf: couldn't wakeup all tasks (0/1) perf: couldn't wakeup all tasks (0/1) In the system, where perf bench wake-up-parallel is has system configuration of 640 cpus. After debugging, this turned out to be a timing issue. The benchmark creates threads equal to number of cpus and issues a futex_wait. Then it does a usleep for .1 second before initiating futex_wake. In system configuration with more threads, the usleep time is not enough. Patch changes the usleep from 100000 to 200000 With the patch, ran multiple iterations and there were no issues further seen Reported-by: Disha Goel Signed-off-by: Athira Rajeev Reviewed-by: Ian Rogers Tested-by: Disha Goel Cc: akanksha@linux.ibm.com Cc: kjain@linux.ibm.com Cc: maddy@linux.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240607044354.82225-3-atrajeev@linux.vnet.ibm.com

tools/perf: Fix perf bench futex to enable the run when some CPU's are offline

2024-06-14T04:26:58Z

Perf bench futex fails as below when attempted to run on on a powerpc system: ./perf bench futex all Running futex/hash benchmark... Run summary [PID 626307]: 80 threads, each operating on 1024 [private] futexes for 10 secs. perf: pthread_create: No such file or directory In the setup where this perf bench was ran, difference was that partition had 640 CPU's, but not all CPUs were online. 80 CPUs were online. While blocking the threads with futex_wait, code sets the affinity using cpumask. The cpumask size used is 80 which is picked from "nrcpus = perf_cpu_map__nr(cpu)". Here the benchmark reports fail while setting affinity for cpu number which is greater than 80 or higher, because it attempts to set a bit position which is not allocated on the cpumask. Fix this by changing the size of cpumask to number of possible cpus and not the number of online cpus. Signed-off-by: Athira Rajeev Reviewed-by: Ian Rogers Tested-by: Disha Goel Cc: akanksha@linux.ibm.com Cc: kjain@linux.ibm.com Cc: maddy@linux.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240607044354.82225-1-atrajeev@linux.vnet.ibm.com

libperf cpumap: Replace usage of perf_cpu_map__new(NULL) with perf_cpu_map__new_online_cpus()

2023-12-12T17:55:13Z

Passing NULL to perf_cpu_map__new() performs perf_cpu_map__new_online_cpus(), just directly call perf_cpu_map__new_online_cpus() to be more intention revealing. Reviewed-by: James Clark Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andrew Jones Cc: André Almeida Cc: Athira Jajeev Cc: Atish Patra Cc: Changbin Du Cc: Darren Hart Cc: Davidlohr Bueso Cc: Huacai Chen Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Nick Desaulniers Cc: Paolo Bonzini Cc: Paran Lee Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Thomas Gleixner Cc: Will Deacon Cc: Yang Jihong Cc: Yang Li Cc: Yanteng Si Cc: bpf@vger.kernel.org Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20231129060211.1890454-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bench futex: Avoid memory leaks from pthread_attr

2023-06-12T21:18:14Z

Remove code sharing the pthread_attr_t and initialize/destroy pthread_attr_t when needed. This avoids the same attribute being set that leak sanitizer reports as a memory leak. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: André Almeida Cc: Darren Hart Cc: Davidlohr Bueso Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lore.kernel.org/r/20230611233610.953456-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bench: Update use of pthread mutex/cond

2022-10-04T11:55:19Z

Switch to the use of mutex wrappers that provide better error checking. Signed-off-by: Ian Rogers Reviewed-by: Adrian Hunter Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Alexandre Truong Cc: Alexey Bayduraev Cc: Andi Kleen Cc: Andres Freund Cc: Andrii Nakryiko Cc: André Almeida Cc: Athira Jajeev Cc: Christophe JAILLET Cc: Colin Ian King Cc: Dario Petrillo Cc: Darren Hart Cc: Dave Marchevsky Cc: Davidlohr Bueso Cc: Fangrui Song Cc: Hewenliang Cc: Ingo Molnar Cc: James Clark Cc: Jason Wang Cc: Jiri Olsa Cc: Kajol Jain Cc: Kim Phillips Cc: Leo Yan Cc: Mark Rutland Cc: Martin Liška Cc: Masami Hiramatsu Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Pavithra Gurushankar Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ravi Bangoria Cc: Remi Bernon Cc: Riccardo Mancini Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Thomas Richter Cc: Tom Rix Cc: Weiguo Li Cc: Wenyu Liu Cc: William Cohen Cc: Zechuan Chen Cc: bpf@vger.kernel.org Cc: llvm@lists.linux.dev Cc: yaowenbin Link: https://lore.kernel.org/r/20220826164242.43412-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bench: Fix futex bench to correct usage of affinity for machines with #CPUs > 1K

2022-04-09T15:34:29Z

The 'perf bench futex' testcase fails on systems with more than 1K CPUs. Testcase: perf bench futex all Failure snippet: <<>>Running futex/hash benchmark... perf: pthread_create: No such file or directory <<>> All the futex benchmarks (ie hash, lock-api, requeue, wake, wake-parallel), pthread_create is invoked in respective bench_futex_* function. Though the logs shows direct failure from pthread_create, strace logs showed that actual failure is from "sched_setaffinity" returning EINVAL (invalid argument). This happens because the default mask size in glibc is 1024. To overcome this 1024 CPUs mask size limitation of cpu_set_t, change the mask size using the CPU_*_S macros. Patch addresses this by fixing all the futex benchmarks to use CPU_ALLOC to allocate cpumask, CPU_ALLOC_SIZE for size, and CPU_SET_S to set the mask. Reported-by: Disha Goel Reviewed-by: Srikar Dronamraju Signed-off-by: Athira Jajeev Tested-by: Disha Goel Acked-by: Ian Rogers Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nageswara R Sastry Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20220406175113.87881-2-atrajeev@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Migrate to libperf cpumap api

2022-01-22T20:08:42Z

Switch from directly accessing the perf_cpu_map to using the appropriate libperf API when possible. Using the API simplifies the job of refactoring use of perf_cpu_map. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Andi Kleen Cc: Andrew Morton Cc: André Almeida Cc: Andy Shevchenko Cc: Darren Hart Cc: Davidlohr Bueso Cc: Dmitriy Vyukov Cc: Eric Dumazet Cc: German Gomez Cc: James Clark Cc: Jin Yao Cc: Jiri Olsa Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Madhavan Srinivasan Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Shunsuke Nakamura Cc: Song Liu Cc: Stephane Eranian Cc: Stephen Brennan Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Thomas Richter Cc: Yury Norov Link: http://lore.kernel.org/lkml/20220122045811.3402706-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Give CPUs their own type

2022-01-12T17:28:23Z

A common problem is confusing CPU map indices with the CPU, by wrapping the CPU with a struct then this is avoided. This approach is similar to atomic_t. Committer notes: To make it build with BUILD_BPF_SKEL=1 these files needed the conversions to 'struct perf_cpu' usage: tools/perf/util/bpf_counter.c tools/perf/util/bpf_counter_cgroup.c tools/perf/util/bpf_ftrace.c Also perf_env__get_cpu() was removed back in "perf cpumap: Switch cpu_map__build_map to cpu function". Additionally these needed to be fixed for the ARM builds to complete: tools/perf/arch/arm/util/cs-etm.c tools/perf/arch/arm64/util/pmu.c Suggested-by: John Garry Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Mathieu Poirier Cc: Mike Leach Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Stephane Eranian Cc: Suzuki Poulouse Cc: Vineet Singh Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: zhengjun.xing@intel.com Link: https://lore.kernel.org/r/20220105061351.120843-49-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo