From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- tools/perf/tests/keep-tracking.c | 164 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) create mode 100644 tools/perf/tests/keep-tracking.c (limited to 'tools/perf/tests/keep-tracking.c') diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c new file mode 100644 index 000000000..729cc9cc1 --- /dev/null +++ b/tools/perf/tests/keep-tracking.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "parse-events.h" +#include "evlist.h" +#include "evsel.h" +#include "record.h" +#include "thread_map.h" +#include "tests.h" +#include "util/mmap.h" + +#define CHECK__(x) { \ + while ((x) < 0) { \ + pr_debug(#x " failed!\n"); \ + goto out_err; \ + } \ +} + +#define CHECK_NOT_NULL__(x) { \ + while ((x) == NULL) { \ + pr_debug(#x " failed!\n"); \ + goto out_err; \ + } \ +} + +static int find_comm(struct evlist *evlist, const char *comm) +{ + union perf_event *event; + struct mmap *md; + int i, found; + + found = 0; + for (i = 0; i < evlist->core.nr_mmaps; i++) { + md = &evlist->mmap[i]; + if (perf_mmap__read_init(&md->core) < 0) + continue; + while ((event = perf_mmap__read_event(&md->core)) != NULL) { + if (event->header.type == PERF_RECORD_COMM && + (pid_t)event->comm.pid == getpid() && + (pid_t)event->comm.tid == getpid() && + strcmp(event->comm.comm, comm) == 0) + found += 1; + perf_mmap__consume(&md->core); + } + perf_mmap__read_done(&md->core); + } + return found; +} + +/** + * test__keep_tracking - test using a dummy software event to keep tracking. + * + * This function implements a test that checks that tracking events continue + * when an event is disabled but a dummy software event is not disabled. If the + * test passes %0 is returned, otherwise %-1 is returned. + */ +static int test__keep_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + struct record_opts opts = { + .mmap_pages = UINT_MAX, + .user_freq = UINT_MAX, + .user_interval = ULLONG_MAX, + .target = { + .uses_mmap = true, + }, + }; + struct perf_thread_map *threads = NULL; + struct perf_cpu_map *cpus = NULL; + struct evlist *evlist = NULL; + struct evsel *evsel = NULL; + int found, err = -1; + const char *comm; + + threads = thread_map__new_by_tid(getpid()); + CHECK_NOT_NULL__(threads); + + cpus = perf_cpu_map__new_online_cpus(); + CHECK_NOT_NULL__(cpus); + + evlist = evlist__new(); + CHECK_NOT_NULL__(evlist); + + perf_evlist__set_maps(&evlist->core, cpus, threads); + + CHECK__(parse_event(evlist, "dummy:u")); + CHECK__(parse_event(evlist, "cpu-cycles:u")); + + evlist__config(evlist, &opts, NULL); + + evsel = evlist__first(evlist); + + evsel->core.attr.comm = 1; + evsel->core.attr.disabled = 1; + evsel->core.attr.enable_on_exec = 0; + + if (evlist__open(evlist) < 0) { + pr_debug("Unable to open dummy and cycles event\n"); + err = TEST_SKIP; + goto out_err; + } + + CHECK__(evlist__mmap(evlist, UINT_MAX)); + + /* + * First, test that a 'comm' event can be found when the event is + * enabled. + */ + + evlist__enable(evlist); + + comm = "Test COMM 1"; + CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0)); + + evlist__disable(evlist); + + found = find_comm(evlist, comm); + if (found != 1) { + pr_debug("First time, failed to find tracking event.\n"); + goto out_err; + } + + /* + * Secondly, test that a 'comm' event can be found when the event is + * disabled with the dummy event still enabled. + */ + + evlist__enable(evlist); + + evsel = evlist__last(evlist); + + CHECK__(evsel__disable(evsel)); + + comm = "Test COMM 2"; + CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0)); + + evlist__disable(evlist); + + found = find_comm(evlist, comm); + if (found != 1) { + pr_debug("Second time, failed to find tracking event.\n"); + goto out_err; + } + + err = 0; + +out_err: + if (evlist) { + evlist__disable(evlist); + evlist__delete(evlist); + } + perf_cpu_map__put(cpus); + perf_thread_map__put(threads); + + return err; +} + +DEFINE_SUITE("Use a dummy software event to keep tracking", keep_tracking); -- cgit v1.3.1