// SPDX-License-Identifier: GPL-2.0+//// Torture test for smp_call_function() and friends.//// Copyright (C) Facebook, 2020.//// Author: Paul E. McKenney <paulmck@kernel.org> #define pr_fmt(fmt) fmt #include <linux/atomic.h>#include <linux/bitops.h>#include <linux/completion.h>#include <linux/cpu.h>#include <linux/delay.h>#include <linux/err.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/kthread.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/notifier.h>#include <linux/percpu.h>#include <linux/rcupdate.h>#include <linux/rcupdate_trace.h>#include <linux/reboot.h>#include <linux/sched.h>#include <linux/spinlock.h>#include <linux/smp.h>#include <linux/stat.h>#include <linux/srcu.h>#include <linux/slab.h>#include <linux/torture.h>#include <linux/types.h> #define SCFTORT_STRING "scftorture"#define SCFTORT_FLAG SCFTORT_STRING ": " #define SCFTORTOUT(s, x...) \ pr_alert(SCFTORT_FLAG s, ## x) #define VERBOSE_SCFTORTOUT(s, x...) \ do { if (verbose) pr_alert(SCFTORT_FLAG s, ## x); } while (0) #define VERBOSE_SCFTORTOUT_ERRSTRING(s, x...) \ do { if (verbose) pr_alert(SCFTORT_FLAG "!!! " s, ## x); } while (0) MODULE_LICENSE("GPL");MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>"); // Wait until there are multiple CPUs before starting test.torture_param(int, holdoff, IS_BUILTIN(CONFIG_SCF_TORTURE_TEST) ? 10 : 0, "Holdoff time before test start (s)");torture_param(int, longwait, 0, "Include ridiculously long waits? (seconds)");torture_param(int, nthreads, -1, "# threads, defaults to -1 for all CPUs.");torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (s), 0=disable");torture_param(int, shutdown_secs, 0, "Shutdown time (ms), <= zero to disable.");torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s.");torture_param(int, stutter_cpus, 5, "Number of jiffies to change CPUs under test, 0=disable");torture_param(bool, use_cpus_read_lock, 0, "Use cpus_read_lock() to exclude CPU hotplug.");torture_param(int, verbose, 0, "Enable verbose debugging printk()s");torture_param(int, weight_single, -1, "Testing weight for single-CPU no-wait operations.");torture_param(int, weight_single_wait, -1, "Testing weight for single-CPU operations.");torture_param(int, weight_many, -1, "Testing weight for multi-CPU no-wait operations.");torture_param(int, weight_many_wait, -1, "Testing weight for multi-CPU operations.");torture_param(int, weight_all, -1, "Testing weight for all-CPU no-wait operations.");torture_param(int, weight_all_wait, -1, "Testing weight for all-CPU operations."); char *torture_type = ""; #ifdef MODULE# define SCFTORT_SHUTDOWN 0#else# define SCFTORT_SHUTDOWN 1#endif torture_param(bool, shutdown, SCFTORT_SHUTDOWN, "Shutdown at end of torture test."); struct scf_statistics { struct task_struct *task; int cpu; long long n_single; long long n_single_ofl; long long n_single_wait; long long n_single_wait_ofl; long long n_many; long long n_many_wait; long long n_all; long long n_all_wait;}; static struct scf_statistics *scf_stats_p;static struct task_struct *scf_torture_stats_task;static DEFINE_PER_CPU(long long, scf_invoked_count); // Data for random primitive selection#define SCF_PRIM_SINGLE 0#define SCF_PRIM_MANY 1#define SCF_PRIM_ALL 2#define SCF_NPRIMS (2 * 3) // Need wait and no-wait versions of each. static char *scf_prim_name[] = { "smp_call_function_single", "smp_call_function_many", "smp_call_function",}; struct scf_selector { unsigned long scfs_weight; int scfs_prim; bool scfs_wait;};static struct scf_selector scf_sel_array[SCF_NPRIMS];static int scf_sel_array_len;static unsigned long scf_sel_totweight; // Communicate between caller and handler.struct scf_check { bool scfc_in; bool scfc_out; int scfc_cpu; // -1 for not _single(). bool scfc_wait;}; // Use to wait for all threads to start.static atomic_t n_started;static atomic_t n_errs;static atomic_t n_mb_in_errs;static atomic_t n_mb_out_errs;static atomic_t n_alloc_errs;static bool scfdone;static char *bangstr = ""; static DEFINE_TORTURE_RANDOM_PERCPU(scf_torture_rand); // Print torture statistics. Caller must ensure serialization.static void scf_torture_stats_print(void){ int cpu; int i; long long invoked_count = 0; bool isdone = READ_ONCE(scfdone); struct scf_statistics scfs = {}; for_each_possible_cpu(cpu) invoked_count += data_race(per_cpu(scf_invoked_count, cpu)); for (i = 0; i < nthreads; i++) { scfs.n_single += scf_stats_p[i].n_single; scfs.n_single_ofl += scf_stats_p[i].n_single_ofl; scfs.n_single_wait += scf_stats_p[i].n_single_wait; scfs.n_single_wait_ofl += scf_stats_p[i].n_single_wait_ofl; scfs.n_many += scf_stats_p[i].n_many; scfs.n_many_wait += scf_stats_p[i].n_many_wait; scfs.n_all += scf_stats_p[i].n_all; scfs.n_all_wait += scf_stats_p[i].n_all_wait; } if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs) || atomic_read(&n_alloc_errs)) bangstr = "!!! "; pr_alert("%s %sscf_invoked_count %s: %lld single: %lld/%lld single_ofl: %lld/%lld many: %lld/%lld all: %lld/%lld ", SCFTORT_FLAG, bangstr, isdone ? "VER" : "ver", invoked_count, scfs.n_single, scfs.n_single_wait, scfs.n_single_ofl, scfs.n_single_wait_ofl, scfs.n_many, scfs.n_many_wait, scfs.n_all, scfs.n_all_wait); torture_onoff_stats(); pr_cont("ste: %d stnmie: %d stnmoe: %d staf: %d\n", atomic_read(&n_errs), atomic_read(&n_mb_in_errs), atomic_read(&n_mb_out_errs), atomic_read(&n_alloc_errs));} // Periodically prints torture statistics, if periodic statistics printing// was specified via the stat_interval module parameter.static intscf_torture_stats(void *arg){ VERBOSE_TOROUT_STRING("scf_torture_stats task started"); do { schedule_timeout_interruptible(stat_interval * HZ); scf_torture_stats_print(); torture_shutdown_absorb("scf_torture_stats"); } while (!torture_must_stop()); torture_kthread_stopping("scf_torture_stats"); return 0;} // Add a primitive to the scf_sel_array[].static void scf_sel_add(unsigned long weight, int prim, bool wait){ struct scf_selector *scfsp = &scf_sel_array[scf_sel_array_len]; // If no weight, if array would overflow, if computing three-place // percentages would overflow, or if the scf_prim_name[] array would // overflow, don't bother. In the last three two cases, complain. if (!weight || WARN_ON_ONCE(scf_sel_array_len >= ARRAY_SIZE(scf_sel_array)) || WARN_ON_ONCE(0 - 100000 * weight <= 100000 * scf_sel_totweight) || WARN_ON_ONCE(prim >= ARRAY_SIZE(scf_prim_name))) return; scf_sel_totweight += weight; scfsp->scfs_weight = scf_sel_totweight; scfsp->scfs_prim = prim; scfsp->scfs_wait = wait; scf_sel_array_len++;} // Dump out weighting percentages for scf_prim_name[] array.static void scf_sel_dump(void){ int i; unsigned long oldw = 0; struct scf_selector *scfsp; unsigned long w; for (i = 0; i < scf_sel_array_len; i++) { scfsp = &scf_sel_array[i]; w = (scfsp->scfs_weight - oldw) * 100000 / scf_sel_totweight; pr_info("%s: %3lu.%03lu %s(%s)\n", __func__, w / 1000, w % 1000, scf_prim_name[scfsp->scfs_prim], scfsp->scfs_wait ? "wait" : "nowait"); oldw = scfsp->scfs_weight; }} // Randomly pick a primitive and wait/nowait, based on weightings.static struct scf_selector *scf_sel_rand(struct torture_random_state *trsp){ int i; unsigned long w = torture_random(trsp) % (scf_sel_totweight + 1); for (i = 0; i < scf_sel_array_len; i++) if (scf_sel_array[i].scfs_weight >= w) return &scf_sel_array[i]; WARN_ON_ONCE(1); return &scf_sel_array[0];} // Update statistics and occasionally burn up mass quantities of CPU time,// if told to do so via scftorture.longwait. Otherwise, occasionally burn// a little bit.static void scf_handler(void *scfc_in){ int i; int j; unsigned long r = torture_random(this_cpu_ptr(&scf_torture_rand)); struct scf_check *scfcp = scfc_in; if (likely(scfcp)) { WRITE_ONCE(scfcp->scfc_out, false); // For multiple receivers. if (WARN_ON_ONCE(unlikely(!READ_ONCE(scfcp->scfc_in)))) atomic_inc(&n_mb_in_errs); } this_cpu_inc(scf_invoked_count); if (longwait <= 0) { if (!(r & 0xffc0)) udelay(r & 0x3f); goto out; } if (r & 0xfff) goto out; r = (r >> 12); if (longwait <= 0) { udelay((r & 0xff) + 1); goto out; } r = r % longwait + 1; for (i = 0; i < r; i++) { for (j = 0; j < 1000; j++) { udelay(1000); cpu_relax(); } }out: if (unlikely(!scfcp)) return; if (scfcp->scfc_wait) WRITE_ONCE(scfcp->scfc_out, true); else kfree(scfcp);} // As above, but check for correct CPU.static void scf_handler_1(void *scfc_in){ struct scf_check *scfcp = scfc_in; if (likely(scfcp) && WARN_ONCE(smp_processor_id() != scfcp->scfc_cpu, "%s: Wanted CPU %d got CPU %d\n", __func__, scfcp->scfc_cpu, smp_processor_id())) { atomic_inc(&n_errs); } scf_handler(scfcp);} // Randomly do an smp_call_function*() invocation.static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_random_state *trsp){ uintptr_t cpu; int ret = 0; struct scf_check *scfcp = NULL; struct scf_selector *scfsp = scf_sel_rand(trsp); if (use_cpus_read_lock) cpus_read_lock(); else preempt_disable(); if (scfsp->scfs_prim == SCF_PRIM_SINGLE || scfsp->scfs_wait) { scfcp = kmalloc(sizeof(*scfcp), GFP_ATOMIC); if (WARN_ON_ONCE(!scfcp)) { atomic_inc(&n_alloc_errs); } else { scfcp->scfc_cpu = -1; scfcp->scfc_wait = scfsp->scfs_wait; scfcp->scfc_out = false; } } switch (scfsp->scfs_prim) { case SCF_PRIM_SINGLE: cpu = torture_random(trsp) % nr_cpu_ids; if (scfsp->scfs_wait) scfp->n_single_wait++; else scfp->n_single++; if (scfcp) { scfcp->scfc_cpu = cpu; barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } ret = smp_call_function_single(cpu, scf_handler_1, (void *)scfcp, scfsp->scfs_wait); if (ret) { if (scfsp->scfs_wait) scfp->n_single_wait_ofl++; else scfp->n_single_ofl++; kfree(scfcp); scfcp = NULL; } break; case SCF_PRIM_MANY: if (scfsp->scfs_wait) scfp->n_many_wait++; else scfp->n_many++; if (scfcp) { barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } smp_call_function_many(cpu_online_mask, scf_handler, scfcp, scfsp->scfs_wait); break; case SCF_PRIM_ALL: if (scfsp->scfs_wait) scfp->n_all_wait++; else scfp->n_all++; if (scfcp) { barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } smp_call_function(scf_handler, scfcp, scfsp->scfs_wait); break; default: WARN_ON_ONCE(1); if (scfcp) scfcp->scfc_out = true; } if (scfcp && scfsp->scfs_wait) { if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp->scfs_prim == SCF_PRIM_SINGLE) && !scfcp->scfc_out)) atomic_inc(&n_mb_out_errs); // Leak rather than trash! else kfree(scfcp); barrier(); // Prevent race-reduction compiler optimizations. } if (use_cpus_read_lock) cpus_read_unlock(); else preempt_enable(); if (!(torture_random(trsp) & 0xfff)) schedule_timeout_uninterruptible(1);} // SCF test kthread. Repeatedly does calls to members of the// smp_call_function() family of functions.static int scftorture_invoker(void *arg){ int cpu; DEFINE_TORTURE_RANDOM(rand); struct scf_statistics *scfp = (struct scf_statistics *)arg; bool was_offline = false; VERBOSE_SCFTORTOUT("scftorture_invoker %d: task started", scfp->cpu); cpu = scfp->cpu % nr_cpu_ids; set_cpus_allowed_ptr(current, cpumask_of(cpu)); set_user_nice(current, MAX_NICE); if (holdoff) schedule_timeout_interruptible(holdoff * HZ); VERBOSE_SCFTORTOUT("scftorture_invoker %d: Waiting for all SCF torturers from cpu %d", scfp->cpu, smp_processor_id()); // Make sure that the CPU is affinitized appropriately during testing. WARN_ON_ONCE(smp_processor_id() != scfp->cpu); if (!atomic_dec_return(&n_started)) while (atomic_read_acquire(&n_started)) { if (torture_must_stop()) { VERBOSE_SCFTORTOUT("scftorture_invoker %d ended before starting", scfp->cpu); goto end; } schedule_timeout_uninterruptible(1); } VERBOSE_SCFTORTOUT("scftorture_invoker %d started", scfp->cpu); do { scftorture_invoke_one(scfp, &rand); while (cpu_is_offline(cpu) && !torture_must_stop()) { schedule_timeout_interruptible(HZ / 5); was_offline = true; } if (was_offline) { set_cpus_allowed_ptr(current, cpumask_of(cpu)); was_offline = false; } cond_resched(); } while (!torture_must_stop()); VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp->cpu);end: torture_kthread_stopping("scftorture_invoker"); return 0;} static voidscftorture_print_module_parms(const char *tag){ pr_alert(SCFTORT_FLAG "--- %s: verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter_cpus=%d use_cpus_read_lock=%d, weight_single=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag, verbose, holdoff, longwait, nthreads, onoff_holdoff, onoff_interval, shutdown, stat_interval, stutter_cpus, use_cpus_read_lock, weight_single, weight_single_wait, weight_many, weight_many_wait, weight_all, weight_all_wait);} static void scf_cleanup_handler(void *unused){} static void scf_torture_cleanup(void){ int i; if (torture_cleanup_begin()) return; WRITE_ONCE(scfdone, true); if (nthreads) for (i = 0; i < nthreads; i++) torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task); else goto end; smp_call_function(scf_cleanup_handler, NULL, 0); torture_stop_kthread(scf_torture_stats, scf_torture_stats_task); scf_torture_stats_print(); // -After- the stats thread is stopped! kfree(scf_stats_p); // -After- the last stats print has completed! scf_stats_p = NULL; if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs)) scftorture_print_module_parms("End of test: FAILURE"); else if (torture_onoff_failures()) scftorture_print_module_parms("End of test: LOCK_HOTPLUG"); else scftorture_print_module_parms("End of test: SUCCESS"); end: torture_cleanup_end();} static int __init scf_torture_init(void){ long i; int firsterr = 0; unsigned long weight_single1 = weight_single; unsigned long weight_single_wait1 = weight_single_wait; unsigned long weight_many1 = weight_many; unsigned long weight_many_wait1 = weight_many_wait; unsigned long weight_all1 = weight_all; unsigned long weight_all_wait1 = weight_all_wait; if (!torture_init_begin(SCFTORT_STRING, verbose)) return -EBUSY; scftorture_print_module_parms("Start of test"); if (weight_single == -1 && weight_single_wait == -1 && weight_many == -1 && weight_many_wait == -1 && weight_all == -1 && weight_all_wait == -1) { weight_single1 = 2 * nr_cpu_ids; weight_single_wait1 = 2 * nr_cpu_ids; weight_many1 = 2; weight_many_wait1 = 2; weight_all1 = 1; weight_all_wait1 = 1; } else { if (weight_single == -1)Lines 1–500 of 575. 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// SPDX-License-Identifier: GPL-2.0+ // // Torture test for smp_call_function() and friends. // // Copyright (C) Facebook, 2020. // // Author: Paul E. McKenney <paulmck@kernel.org> #define pr_fmt(fmt) fmt #include <linux/atomic.h> #include <linux/bitops.h> #include <linux/completion.h> #include <linux/cpu.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kthread.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/notifier.h> #include <linux/percpu.h> #include <linux/rcupdate.h> #include <linux/rcupdate_trace.h> #include <linux/reboot.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/smp.h> #include <linux/stat.h> #include <linux/srcu.h> #include <linux/slab.h> #include <linux/torture.h> #include <linux/types.h> #define SCFTORT_STRING "scftorture" #define SCFTORT_FLAG SCFTORT_STRING ": " #define SCFTORTOUT(s, x...) \ pr_alert(SCFTORT_FLAG s, ## x) #define VERBOSE_SCFTORTOUT(s, x...) \ do { if (verbose) pr_alert(SCFTORT_FLAG s, ## x); } while (0) #define VERBOSE_SCFTORTOUT_ERRSTRING(s, x...) \ do { if (verbose) pr_alert(SCFTORT_FLAG "!!! " s, ## x); } while (0) MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>"); // Wait until there are multiple CPUs before starting test. torture_param(int, holdoff, IS_BUILTIN(CONFIG_SCF_TORTURE_TEST) ? 10 : 0, "Holdoff time before test start (s)"); torture_param(int, longwait, 0, "Include ridiculously long waits? (seconds)"); torture_param(int, nthreads, -1, "# threads, defaults to -1 for all CPUs."); torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (s), 0=disable"); torture_param(int, shutdown_secs, 0, "Shutdown time (ms), <= zero to disable."); torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s."); torture_param(int, stutter_cpus, 5, "Number of jiffies to change CPUs under test, 0=disable"); torture_param(bool, use_cpus_read_lock, 0, "Use cpus_read_lock() to exclude CPU hotplug."); torture_param(int, verbose, 0, "Enable verbose debugging printk()s"); torture_param(int, weight_single, -1, "Testing weight for single-CPU no-wait operations."); torture_param(int, weight_single_wait, -1, "Testing weight for single-CPU operations."); torture_param(int, weight_many, -1, "Testing weight for multi-CPU no-wait operations."); torture_param(int, weight_many_wait, -1, "Testing weight for multi-CPU operations."); torture_param(int, weight_all, -1, "Testing weight for all-CPU no-wait operations."); torture_param(int, weight_all_wait, -1, "Testing weight for all-CPU operations."); char *torture_type = ""; #ifdef MODULE # define SCFTORT_SHUTDOWN 0 #else # define SCFTORT_SHUTDOWN 1 #endif torture_param(bool, shutdown, SCFTORT_SHUTDOWN, "Shutdown at end of torture test."); struct scf_statistics { struct task_struct *task; int cpu; long long n_single; long long n_single_ofl; long long n_single_wait; long long n_single_wait_ofl; long long n_many; long long n_many_wait; long long n_all; long long n_all_wait; }; static struct scf_statistics *scf_stats_p; static struct task_struct *scf_torture_stats_task; static DEFINE_PER_CPU(long long, scf_invoked_count); // Data for random primitive selection #define SCF_PRIM_SINGLE 0 #define SCF_PRIM_MANY 1 #define SCF_PRIM_ALL 2 #define SCF_NPRIMS (2 * 3) // Need wait and no-wait versions of each. static char *scf_prim_name[] = { "smp_call_function_single", "smp_call_function_many", "smp_call_function", }; struct scf_selector { unsigned long scfs_weight; int scfs_prim; bool scfs_wait; }; static struct scf_selector scf_sel_array[SCF_NPRIMS]; static int scf_sel_array_len; static unsigned long scf_sel_totweight; // Communicate between caller and handler. struct scf_check { bool scfc_in; bool scfc_out; int scfc_cpu; // -1 for not _single(). bool scfc_wait; }; // Use to wait for all threads to start. static atomic_t n_started; static atomic_t n_errs; static atomic_t n_mb_in_errs; static atomic_t n_mb_out_errs; static atomic_t n_alloc_errs; static bool scfdone; static char *bangstr = ""; static DEFINE_TORTURE_RANDOM_PERCPU(scf_torture_rand); // Print torture statistics. Caller must ensure serialization. static void scf_torture_stats_print(void) { int cpu; int i; long long invoked_count = 0; bool isdone = READ_ONCE(scfdone); struct scf_statistics scfs = {}; for_each_possible_cpu(cpu) invoked_count += data_race(per_cpu(scf_invoked_count, cpu)); for (i = 0; i < nthreads; i++) { scfs.n_single += scf_stats_p[i].n_single; scfs.n_single_ofl += scf_stats_p[i].n_single_ofl; scfs.n_single_wait += scf_stats_p[i].n_single_wait; scfs.n_single_wait_ofl += scf_stats_p[i].n_single_wait_ofl; scfs.n_many += scf_stats_p[i].n_many; scfs.n_many_wait += scf_stats_p[i].n_many_wait; scfs.n_all += scf_stats_p[i].n_all; scfs.n_all_wait += scf_stats_p[i].n_all_wait; } if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs) || atomic_read(&n_alloc_errs)) bangstr = "!!! "; pr_alert("%s %sscf_invoked_count %s: %lld single: %lld/%lld single_ofl: %lld/%lld many: %lld/%lld all: %lld/%lld ", SCFTORT_FLAG, bangstr, isdone ? "VER" : "ver", invoked_count, scfs.n_single, scfs.n_single_wait, scfs.n_single_ofl, scfs.n_single_wait_ofl, scfs.n_many, scfs.n_many_wait, scfs.n_all, scfs.n_all_wait); torture_onoff_stats(); pr_cont("ste: %d stnmie: %d stnmoe: %d staf: %d\n", atomic_read(&n_errs), atomic_read(&n_mb_in_errs), atomic_read(&n_mb_out_errs), atomic_read(&n_alloc_errs)); } // Periodically prints torture statistics, if periodic statistics printing // was specified via the stat_interval module parameter. static int scf_torture_stats(void *arg) { VERBOSE_TOROUT_STRING("scf_torture_stats task started"); do { schedule_timeout_interruptible(stat_interval * HZ); scf_torture_stats_print(); torture_shutdown_absorb("scf_torture_stats"); } while (!torture_must_stop()); torture_kthread_stopping("scf_torture_stats"); return 0; } // Add a primitive to the scf_sel_array[]. static void scf_sel_add(unsigned long weight, int prim, bool wait) { struct scf_selector *scfsp = &scf_sel_array[scf_sel_array_len]; // If no weight, if array would overflow, if computing three-place // percentages would overflow, or if the scf_prim_name[] array would // overflow, don't bother. In the last three two cases, complain. if (!weight || WARN_ON_ONCE(scf_sel_array_len >= ARRAY_SIZE(scf_sel_array)) || WARN_ON_ONCE(0 - 100000 * weight <= 100000 * scf_sel_totweight) || WARN_ON_ONCE(prim >= ARRAY_SIZE(scf_prim_name))) return; scf_sel_totweight += weight; scfsp->scfs_weight = scf_sel_totweight; scfsp->scfs_prim = prim; scfsp->scfs_wait = wait; scf_sel_array_len++; } // Dump out weighting percentages for scf_prim_name[] array. static void scf_sel_dump(void) { int i; unsigned long oldw = 0; struct scf_selector *scfsp; unsigned long w; for (i = 0; i < scf_sel_array_len; i++) { scfsp = &scf_sel_array[i]; w = (scfsp->scfs_weight - oldw) * 100000 / scf_sel_totweight; pr_info("%s: %3lu.%03lu %s(%s)\n", __func__, w / 1000, w % 1000, scf_prim_name[scfsp->scfs_prim], scfsp->scfs_wait ? "wait" : "nowait"); oldw = scfsp->scfs_weight; } } // Randomly pick a primitive and wait/nowait, based on weightings. static struct scf_selector *scf_sel_rand(struct torture_random_state *trsp) { int i; unsigned long w = torture_random(trsp) % (scf_sel_totweight + 1); for (i = 0; i < scf_sel_array_len; i++) if (scf_sel_array[i].scfs_weight >= w) return &scf_sel_array[i]; WARN_ON_ONCE(1); return &scf_sel_array[0]; } // Update statistics and occasionally burn up mass quantities of CPU time, // if told to do so via scftorture.longwait. Otherwise, occasionally burn // a little bit. static void scf_handler(void *scfc_in) { int i; int j; unsigned long r = torture_random(this_cpu_ptr(&scf_torture_rand)); struct scf_check *scfcp = scfc_in; if (likely(scfcp)) { WRITE_ONCE(scfcp->scfc_out, false); // For multiple receivers. if (WARN_ON_ONCE(unlikely(!READ_ONCE(scfcp->scfc_in)))) atomic_inc(&n_mb_in_errs); } this_cpu_inc(scf_invoked_count); if (longwait <= 0) { if (!(r & 0xffc0)) udelay(r & 0x3f); goto out; } if (r & 0xfff) goto out; r = (r >> 12); if (longwait <= 0) { udelay((r & 0xff) + 1); goto out; } r = r % longwait + 1; for (i = 0; i < r; i++) { for (j = 0; j < 1000; j++) { udelay(1000); cpu_relax(); } } out: if (unlikely(!scfcp)) return; if (scfcp->scfc_wait) WRITE_ONCE(scfcp->scfc_out, true); else kfree(scfcp); } // As above, but check for correct CPU. static void scf_handler_1(void *scfc_in) { struct scf_check *scfcp = scfc_in; if (likely(scfcp) && WARN_ONCE(smp_processor_id() != scfcp->scfc_cpu, "%s: Wanted CPU %d got CPU %d\n", __func__, scfcp->scfc_cpu, smp_processor_id())) { atomic_inc(&n_errs); } scf_handler(scfcp); } // Randomly do an smp_call_function*() invocation. static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_random_state *trsp) { uintptr_t cpu; int ret = 0; struct scf_check *scfcp = NULL; struct scf_selector *scfsp = scf_sel_rand(trsp); if (use_cpus_read_lock) cpus_read_lock(); else preempt_disable(); if (scfsp->scfs_prim == SCF_PRIM_SINGLE || scfsp->scfs_wait) { scfcp = kmalloc(sizeof(*scfcp), GFP_ATOMIC); if (WARN_ON_ONCE(!scfcp)) { atomic_inc(&n_alloc_errs); } else { scfcp->scfc_cpu = -1; scfcp->scfc_wait = scfsp->scfs_wait; scfcp->scfc_out = false; } } switch (scfsp->scfs_prim) { case SCF_PRIM_SINGLE: cpu = torture_random(trsp) % nr_cpu_ids; if (scfsp->scfs_wait) scfp->n_single_wait++; else scfp->n_single++; if (scfcp) { scfcp->scfc_cpu = cpu; barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } ret = smp_call_function_single(cpu, scf_handler_1, (void *)scfcp, scfsp->scfs_wait); if (ret) { if (scfsp->scfs_wait) scfp->n_single_wait_ofl++; else scfp->n_single_ofl++; kfree(scfcp); scfcp = NULL; } break; case SCF_PRIM_MANY: if (scfsp->scfs_wait) scfp->n_many_wait++; else scfp->n_many++; if (scfcp) { barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } smp_call_function_many(cpu_online_mask, scf_handler, scfcp, scfsp->scfs_wait); break; case SCF_PRIM_ALL: if (scfsp->scfs_wait) scfp->n_all_wait++; else scfp->n_all++; if (scfcp) { barrier(); // Prevent race-reduction compiler optimizations. scfcp->scfc_in = true; } smp_call_function(scf_handler, scfcp, scfsp->scfs_wait); break; default: WARN_ON_ONCE(1); if (scfcp) scfcp->scfc_out = true; } if (scfcp && scfsp->scfs_wait) { if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp->scfs_prim == SCF_PRIM_SINGLE) && !scfcp->scfc_out)) atomic_inc(&n_mb_out_errs); // Leak rather than trash! else kfree(scfcp); barrier(); // Prevent race-reduction compiler optimizations. } if (use_cpus_read_lock) cpus_read_unlock(); else preempt_enable(); if (!(torture_random(trsp) & 0xfff)) schedule_timeout_uninterruptible(1); } // SCF test kthread. Repeatedly does calls to members of the // smp_call_function() family of functions. static int scftorture_invoker(void *arg) { int cpu; DEFINE_TORTURE_RANDOM(rand); struct scf_statistics *scfp = (struct scf_statistics *)arg; bool was_offline = false; VERBOSE_SCFTORTOUT("scftorture_invoker %d: task started", scfp->cpu); cpu = scfp->cpu % nr_cpu_ids; set_cpus_allowed_ptr(current, cpumask_of(cpu)); set_user_nice(current, MAX_NICE); if (holdoff) schedule_timeout_interruptible(holdoff * HZ); VERBOSE_SCFTORTOUT("scftorture_invoker %d: Waiting for all SCF torturers from cpu %d", scfp->cpu, smp_processor_id()); // Make sure that the CPU is affinitized appropriately during testing. WARN_ON_ONCE(smp_processor_id() != scfp->cpu); if (!atomic_dec_return(&n_started)) while (atomic_read_acquire(&n_started)) { if (torture_must_stop()) { VERBOSE_SCFTORTOUT("scftorture_invoker %d ended before starting", scfp->cpu); goto end; } schedule_timeout_uninterruptible(1); } VERBOSE_SCFTORTOUT("scftorture_invoker %d started", scfp->cpu); do { scftorture_invoke_one(scfp, &rand); while (cpu_is_offline(cpu) && !torture_must_stop()) { schedule_timeout_interruptible(HZ / 5); was_offline = true; } if (was_offline) { set_cpus_allowed_ptr(current, cpumask_of(cpu)); was_offline = false; } cond_resched(); } while (!torture_must_stop()); VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp->cpu); end: torture_kthread_stopping("scftorture_invoker"); return 0; } static void scftorture_print_module_parms(const char *tag) { pr_alert(SCFTORT_FLAG "--- %s: verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter_cpus=%d use_cpus_read_lock=%d, weight_single=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag, verbose, holdoff, longwait, nthreads, onoff_holdoff, onoff_interval, shutdown, stat_interval, stutter_cpus, use_cpus_read_lock, weight_single, weight_single_wait, weight_many, weight_many_wait, weight_all, weight_all_wait); } static void scf_cleanup_handler(void *unused) { } static void scf_torture_cleanup(void) { int i; if (torture_cleanup_begin()) return; WRITE_ONCE(scfdone, true); if (nthreads) for (i = 0; i < nthreads; i++) torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task); else goto end; smp_call_function(scf_cleanup_handler, NULL, 0); torture_stop_kthread(scf_torture_stats, scf_torture_stats_task); scf_torture_stats_print(); // -After- the stats thread is stopped! kfree(scf_stats_p); // -After- the last stats print has completed! scf_stats_p = NULL; if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs)) scftorture_print_module_parms("End of test: FAILURE"); else if (torture_onoff_failures()) scftorture_print_module_parms("End of test: LOCK_HOTPLUG"); else scftorture_print_module_parms("End of test: SUCCESS"); end: torture_cleanup_end(); } static int __init scf_torture_init(void) { long i; int firsterr = 0; unsigned long weight_single1 = weight_single; unsigned long weight_single_wait1 = weight_single_wait; unsigned long weight_many1 = weight_many; unsigned long weight_many_wait1 = weight_many_wait; unsigned long weight_all1 = weight_all; unsigned long weight_all_wait1 = weight_all_wait; if (!torture_init_begin(SCFTORT_STRING, verbose)) return -EBUSY; scftorture_print_module_parms("Start of test"); if (weight_single == -1 && weight_single_wait == -1 && weight_many == -1 && weight_many_wait == -1 && weight_all == -1 && weight_all_wait == -1) { weight_single1 = 2 * nr_cpu_ids; weight_single_wait1 = 2 * nr_cpu_ids; weight_many1 = 2; weight_many_wait1 = 2; weight_all1 = 1; weight_all_wait1 = 1; } else { if (weight_single == -1)