diff options
Diffstat (limited to 'tools/tracing/rtla/src/timerlat_aa.c')
| -rw-r--r-- | tools/tracing/rtla/src/timerlat_aa.c | 990 |
1 files changed, 990 insertions, 0 deletions
diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c new file mode 100644 index 000000000000..ec4e0f4b0e6c --- /dev/null +++ b/tools/tracing/rtla/src/timerlat_aa.c @@ -0,0 +1,990 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org> + */ + +#include <stdlib.h> +#include <errno.h> +#include "utils.h" +#include "osnoise.h" +#include "timerlat.h" + +enum timelat_state { + TIMERLAT_INIT = 0, + TIMERLAT_WAITING_IRQ, + TIMERLAT_WAITING_THREAD, +}; + +#define MAX_COMM 24 + +/* + * Per-cpu data statistics and data. + */ +struct timerlat_aa_data { + /* Current CPU state */ + int curr_state; + + /* timerlat IRQ latency */ + unsigned long long tlat_irq_seqnum; + unsigned long long tlat_irq_latency; + unsigned long long tlat_irq_timstamp; + + /* timerlat Thread latency */ + unsigned long long tlat_thread_seqnum; + unsigned long long tlat_thread_latency; + unsigned long long tlat_thread_timstamp; + + /* + * Information about the thread running when the IRQ + * arrived. + * + * This can be blocking or interference, depending on the + * priority of the thread. Assuming timerlat is the highest + * prio, it is blocking. If timerlat has a lower prio, it is + * interference. + * note: "unsigned long long" because they are fetch using tep_get_field_val(); + */ + unsigned long long run_thread_pid; + char run_thread_comm[MAX_COMM]; + unsigned long long thread_blocking_duration; + unsigned long long max_exit_idle_latency; + + /* Information about the timerlat timer irq */ + unsigned long long timer_irq_start_time; + unsigned long long timer_irq_start_delay; + unsigned long long timer_irq_duration; + unsigned long long timer_exit_from_idle; + + /* + * Information about the last IRQ before the timerlat irq + * arrived. + * + * If now - timestamp is <= latency, it might have influenced + * in the timerlat irq latency. Otherwise, ignore it. + */ + unsigned long long prev_irq_duration; + unsigned long long prev_irq_timstamp; + + /* + * Interference sum. + */ + unsigned long long thread_nmi_sum; + unsigned long long thread_irq_sum; + unsigned long long thread_softirq_sum; + unsigned long long thread_thread_sum; + + /* + * Interference task information. + */ + struct trace_seq *prev_irqs_seq; + struct trace_seq *nmi_seq; + struct trace_seq *irqs_seq; + struct trace_seq *softirqs_seq; + struct trace_seq *threads_seq; + struct trace_seq *stack_seq; + + /* + * Current thread. + */ + char current_comm[MAX_COMM]; + unsigned long long current_pid; + + /* + * Is the system running a kworker? + */ + unsigned long long kworker; + unsigned long long kworker_func; +}; + +/* + * The analysis context and system wide view + */ +struct timerlat_aa_context { + int nr_cpus; + int dump_tasks; + + /* per CPU data */ + struct timerlat_aa_data *taa_data; + + /* + * required to translate function names and register + * events. + */ + struct osnoise_tool *tool; +}; + +/* + * The data is stored as a local variable, but accessed via a helper function. + * + * It could be stored inside the trace context. But every access would + * require container_of() + a series of pointers. Do we need it? Not sure. + * + * For now keep it simple. If needed, store it in the tool, add the *context + * as a parameter in timerlat_aa_get_ctx() and do the magic there. + */ +static struct timerlat_aa_context *__timerlat_aa_ctx; + +static struct timerlat_aa_context *timerlat_aa_get_ctx(void) +{ + return __timerlat_aa_ctx; +} + +/* + * timerlat_aa_get_data - Get the per-cpu data from the timerlat context + */ +static struct timerlat_aa_data +*timerlat_aa_get_data(struct timerlat_aa_context *taa_ctx, int cpu) +{ + return &taa_ctx->taa_data[cpu]; +} + +/* + * timerlat_aa_irq_latency - Handles timerlat IRQ event + */ +static int timerlat_aa_irq_latency(struct timerlat_aa_data *taa_data, + struct trace_seq *s, struct tep_record *record, + struct tep_event *event) +{ + /* + * For interference, we start now looking for things that can delay + * the thread. + */ + taa_data->curr_state = TIMERLAT_WAITING_THREAD; + taa_data->tlat_irq_timstamp = record->ts; + + /* + * Zero values. + */ + taa_data->thread_nmi_sum = 0; + taa_data->thread_irq_sum = 0; + taa_data->thread_softirq_sum = 0; + taa_data->thread_blocking_duration = 0; + taa_data->timer_irq_start_time = 0; + taa_data->timer_irq_duration = 0; + taa_data->timer_exit_from_idle = 0; + + /* + * Zero interference tasks. + */ + trace_seq_reset(taa_data->nmi_seq); + trace_seq_reset(taa_data->irqs_seq); + trace_seq_reset(taa_data->softirqs_seq); + trace_seq_reset(taa_data->threads_seq); + + /* IRQ latency values */ + tep_get_field_val(s, event, "timer_latency", record, &taa_data->tlat_irq_latency, 1); + tep_get_field_val(s, event, "seqnum", record, &taa_data->tlat_irq_seqnum, 1); + + /* The thread that can cause blocking */ + tep_get_common_field_val(s, event, "common_pid", record, &taa_data->run_thread_pid, 1); + + /* + * Get exit from idle case. + * + * If it is not idle thread: + */ + if (taa_data->run_thread_pid) + return 0; + + /* + * if the latency is shorter than the known exit from idle: + */ + if (taa_data->tlat_irq_latency < taa_data->max_exit_idle_latency) + return 0; + + /* + * To be safe, ignore the cases in which an IRQ/NMI could have + * interfered with the timerlat IRQ. + */ + if (taa_data->tlat_irq_timstamp - taa_data->tlat_irq_latency + < taa_data->prev_irq_timstamp + taa_data->prev_irq_duration) + return 0; + + taa_data->max_exit_idle_latency = taa_data->tlat_irq_latency; + + return 0; +} + +/* + * timerlat_aa_thread_latency - Handles timerlat thread event + */ +static int timerlat_aa_thread_latency(struct timerlat_aa_data *taa_data, + struct trace_seq *s, struct tep_record *record, + struct tep_event *event) +{ + /* + * For interference, we start now looking for things that can delay + * the IRQ of the next cycle. + */ + taa_data->curr_state = TIMERLAT_WAITING_IRQ; + taa_data->tlat_thread_timstamp = record->ts; + + /* Thread latency values */ + tep_get_field_val(s, event, "timer_latency", record, &taa_data->tlat_thread_latency, 1); + tep_get_field_val(s, event, "seqnum", record, &taa_data->tlat_thread_seqnum, 1); + + return 0; +} + +/* + * timerlat_aa_handler - Handle timerlat events + * + * This function is called to handle timerlat events recording statistics. + * + * Returns 0 on success, -1 otherwise. + */ +int timerlat_aa_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long long thread; + + if (!taa_data) + return -1; + + tep_get_field_val(s, event, "context", record, &thread, 1); + if (!thread) + return timerlat_aa_irq_latency(taa_data, s, record, event); + else + return timerlat_aa_thread_latency(taa_data, s, record, event); +} + +/* + * timerlat_aa_nmi_handler - Handles NMI noise + * + * It is used to collect information about interferences from NMI. It is + * hooked to the osnoise:nmi_noise event. + */ +static int timerlat_aa_nmi_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long long duration; + unsigned long long start; + + tep_get_field_val(s, event, "duration", record, &duration, 1); + tep_get_field_val(s, event, "start", record, &start, 1); + + if (taa_data->curr_state == TIMERLAT_WAITING_IRQ) { + taa_data->prev_irq_duration = duration; + taa_data->prev_irq_timstamp = start; + + trace_seq_reset(taa_data->prev_irqs_seq); + trace_seq_printf(taa_data->prev_irqs_seq, "\t%24s \t\t\t%9.2f us\n", + "nmi", ns_to_usf(duration)); + return 0; + } + + taa_data->thread_nmi_sum += duration; + trace_seq_printf(taa_data->nmi_seq, " %24s \t\t\t%9.2f us\n", + "nmi", ns_to_usf(duration)); + + return 0; +} + +/* + * timerlat_aa_irq_handler - Handles IRQ noise + * + * It is used to collect information about interferences from IRQ. It is + * hooked to the osnoise:irq_noise event. + * + * It is a little bit more complex than the other because it measures: + * - The IRQs that can delay the timer IRQ before it happened. + * - The Timerlat IRQ handler + * - The IRQs that happened between the timerlat IRQ and the timerlat thread + * (IRQ interference). + */ +static int timerlat_aa_irq_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long long expected_start; + unsigned long long duration; + unsigned long long vector; + unsigned long long start; + char *desc; + int val; + + tep_get_field_val(s, event, "duration", record, &duration, 1); + tep_get_field_val(s, event, "start", record, &start, 1); + tep_get_field_val(s, event, "vector", record, &vector, 1); + desc = tep_get_field_raw(s, event, "desc", record, &val, 1); + + /* + * Before the timerlat IRQ. + */ + if (taa_data->curr_state == TIMERLAT_WAITING_IRQ) { + taa_data->prev_irq_duration = duration; + taa_data->prev_irq_timstamp = start; + + trace_seq_reset(taa_data->prev_irqs_seq); + trace_seq_printf(taa_data->prev_irqs_seq, "\t%24s:%-3llu \t\t%9.2f us\n", + desc, vector, ns_to_usf(duration)); + return 0; + } + + /* + * The timerlat IRQ: taa_data->timer_irq_start_time is zeroed at + * the timerlat irq handler. + */ + if (!taa_data->timer_irq_start_time) { + expected_start = taa_data->tlat_irq_timstamp - taa_data->tlat_irq_latency; + + taa_data->timer_irq_start_time = start; + taa_data->timer_irq_duration = duration; + + taa_data->timer_irq_start_delay = taa_data->timer_irq_start_time - expected_start; + + /* + * not exit from idle. + */ + if (taa_data->run_thread_pid) + return 0; + + if (expected_start > taa_data->prev_irq_timstamp + taa_data->prev_irq_duration) + taa_data->timer_exit_from_idle = taa_data->timer_irq_start_delay; + + return 0; + } + + /* + * IRQ interference. + */ + taa_data->thread_irq_sum += duration; + trace_seq_printf(taa_data->irqs_seq, " %24s:%-3llu \t %9.2f us\n", + desc, vector, ns_to_usf(duration)); + + return 0; +} + +static char *softirq_name[] = { "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", + "IRQ_POLL", "TASKLET", "SCHED", "HRTIMER", "RCU" }; + + +/* + * timerlat_aa_softirq_handler - Handles Softirq noise + * + * It is used to collect information about interferences from Softirq. It is + * hooked to the osnoise:softirq_noise event. + * + * It is only printed in the non-rt kernel, as softirqs become thread on RT. + */ +static int timerlat_aa_softirq_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long long duration; + unsigned long long vector; + unsigned long long start; + + if (taa_data->curr_state == TIMERLAT_WAITING_IRQ) + return 0; + + tep_get_field_val(s, event, "duration", record, &duration, 1); + tep_get_field_val(s, event, "start", record, &start, 1); + tep_get_field_val(s, event, "vector", record, &vector, 1); + + taa_data->thread_softirq_sum += duration; + + trace_seq_printf(taa_data->softirqs_seq, "\t%24s:%-3llu \t %9.2f us\n", + softirq_name[vector], vector, ns_to_usf(duration)); + return 0; +} + +/* + * timerlat_aa_softirq_handler - Handles thread noise + * + * It is used to collect information about interferences from threads. It is + * hooked to the osnoise:thread_noise event. + * + * Note: if you see thread noise, your timerlat thread was not the highest prio one. + */ +static int timerlat_aa_thread_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long long duration; + unsigned long long start; + unsigned long long pid; + const char *comm; + int val; + + if (taa_data->curr_state == TIMERLAT_WAITING_IRQ) + return 0; + + tep_get_field_val(s, event, "duration", record, &duration, 1); + tep_get_field_val(s, event, "start", record, &start, 1); + + tep_get_common_field_val(s, event, "common_pid", record, &pid, 1); + comm = tep_get_field_raw(s, event, "comm", record, &val, 1); + + if (pid == taa_data->run_thread_pid && !taa_data->thread_blocking_duration) { + taa_data->thread_blocking_duration = duration; + + if (comm) + strncpy(taa_data->run_thread_comm, comm, MAX_COMM); + else + sprintf(taa_data->run_thread_comm, "<...>"); + + } else { + taa_data->thread_thread_sum += duration; + + trace_seq_printf(taa_data->threads_seq, "\t%24s:%-3llu \t\t%9.2f us\n", + comm, pid, ns_to_usf(duration)); + } + + return 0; +} + +/* + * timerlat_aa_stack_handler - Handles timerlat IRQ stack trace + * + * Saves and parse the stack trace generated by the timerlat IRQ. + */ +static int timerlat_aa_stack_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + unsigned long *caller; + const char *function; + int val, i; + + trace_seq_reset(taa_data->stack_seq); + + trace_seq_printf(taa_data->stack_seq, " Blocking thread stack trace\n"); + caller = tep_get_field_raw(s, event, "caller", record, &val, 1); + if (caller) { + for (i = 0; ; i++) { + function = tep_find_function(taa_ctx->tool->trace.tep, caller[i]); + if (!function) + break; + trace_seq_printf(taa_data->stack_seq, "\t\t-> %s\n", function); + } + } + return 0; +} + +/* + * timerlat_aa_sched_switch_handler - Tracks the current thread running on the CPU + * + * Handles the sched:sched_switch event to trace the current thread running on the + * CPU. It is used to display the threads running on the other CPUs when the trace + * stops. + */ +static int timerlat_aa_sched_switch_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + const char *comm; + int val; + + tep_get_field_val(s, event, "next_pid", record, &taa_data->current_pid, 1); + comm = tep_get_field_raw(s, event, "next_comm", record, &val, 1); + + strncpy(taa_data->current_comm, comm, MAX_COMM); + + /* + * If this was a kworker, clean the last kworkers that ran. + */ + taa_data->kworker = 0; + taa_data->kworker_func = 0; + + return 0; +} + +/* + * timerlat_aa_kworker_start_handler - Tracks a kworker running on the CPU + * + * Handles workqueue:workqueue_execute_start event, keeping track of + * the job that a kworker could be doing in the CPU. + * + * We already catch problems of hardware related latencies caused by work queues + * running driver code that causes hardware stall. For example, with DRM drivers. + */ +static int timerlat_aa_kworker_start_handler(struct trace_seq *s, struct tep_record *record, + struct tep_event *event, void *context) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + struct timerlat_aa_data *taa_data = timerlat_aa_get_data(taa_ctx, record->cpu); + + tep_get_field_val(s, event, "work", record, &taa_data->kworker, 1); + tep_get_field_val(s, event, "function", record, &taa_data->kworker_func, 1); + return 0; +} + +/* + * timerlat_thread_analysis - Prints the analysis of a CPU that hit a stop tracing + * + * This is the core of the analysis. + */ +static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu, + int irq_thresh, int thread_thresh) +{ + unsigned long long exp_irq_ts; + int total; + int irq; + + /* + * IRQ latency or Thread latency? + */ + if (taa_data->tlat_irq_seqnum > taa_data->tlat_thread_seqnum) { + irq = 1; + total = taa_data->tlat_irq_latency; + } else { + irq = 0; + total = taa_data->tlat_thread_latency; + } + + /* + * Expected IRQ arrival time using the trace clock as the base. + */ + exp_irq_ts = taa_data->timer_irq_start_time - taa_data->timer_irq_start_delay; + + if (exp_irq_ts < taa_data->prev_irq_timstamp + taa_data->prev_irq_duration) + printf(" Previous IRQ interference: \t up to %9.2f us", + ns_to_usf(taa_data->prev_irq_duration)); + + /* + * The delay that the IRQ suffered before starting. + */ + printf(" IRQ handler delay: %16s %9.2f us (%.2f %%)\n", + (ns_to_usf(taa_data->timer_exit_from_idle) > 10) ? "(exit from idle)" : "", + ns_to_usf(taa_data->timer_irq_start_delay), + ns_to_per(total, taa_data->timer_irq_start_delay)); + + /* + * Timerlat IRQ. + */ + printf(" IRQ latency: \t\t\t\t %9.2f us\n", + ns_to_usf(taa_data->tlat_irq_latency)); + + if (irq) { + /* + * If the trace stopped due to IRQ, the other events will not happen + * because... the trace stopped :-). + * + * That is all folks, the stack trace was printed before the stop, + * so it will be displayed, it is the key. + */ + printf(" Blocking thread:\n"); + printf(" %24s:%-9llu\n", + taa_data->run_thread_comm, taa_data->run_thread_pid); + } else { + /* + * The duration of the IRQ handler that handled the timerlat IRQ. + */ + printf(" Timerlat IRQ duration: \t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->timer_irq_duration), + ns_to_per(total, taa_data->timer_irq_duration)); + + /* + * The amount of time that the current thread postponed the scheduler. + * + * Recalling that it is net from NMI/IRQ/Softirq interference, so there + * is no need to compute values here. + */ + printf(" Blocking thread: \t\t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->thread_blocking_duration), + ns_to_per(total, taa_data->thread_blocking_duration)); + + printf(" %24s:%-9llu %9.2f us\n", + taa_data->run_thread_comm, taa_data->run_thread_pid, + ns_to_usf(taa_data->thread_blocking_duration)); + } + + /* + * Print the stack trace! + */ + trace_seq_do_printf(taa_data->stack_seq); + + /* + * NMIs can happen during the IRQ, so they are always possible. + */ + if (taa_data->thread_nmi_sum) + printf(" NMI interference \t\t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->thread_nmi_sum), + ns_to_per(total, taa_data->thread_nmi_sum)); + + /* + * If it is an IRQ latency, the other factors can be skipped. + */ + if (irq) + goto print_total; + + /* + * Prints the interference caused by IRQs to the thread latency. + */ + if (taa_data->thread_irq_sum) { + printf(" IRQ interference \t\t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->thread_irq_sum), + ns_to_per(total, taa_data->thread_irq_sum)); + + trace_seq_do_printf(taa_data->irqs_seq); + } + + /* + * Prints the interference caused by Softirqs to the thread latency. + */ + if (taa_data->thread_softirq_sum) { + printf(" Softirq interference \t\t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->thread_softirq_sum), + ns_to_per(total, taa_data->thread_softirq_sum)); + + trace_seq_do_printf(taa_data->softirqs_seq); + } + + /* + * Prints the interference caused by other threads to the thread latency. + * + * If this happens, your timerlat is not the highest prio. OK, migration + * thread can happen. But otherwise, you are not measuring the "scheduling + * latency" only, and here is the difference from scheduling latency and + * timer handling latency. + */ + if (taa_data->thread_thread_sum) { + printf(" Thread interference \t\t\t %9.2f us (%.2f %%)\n", + ns_to_usf(taa_data->thread_thread_sum), + ns_to_per(total, taa_data->thread_thread_sum)); + + trace_seq_do_printf(taa_data->threads_seq); + } + + /* + * Done. + */ +print_total: + printf("------------------------------------------------------------------------\n"); + printf(" %s latency: \t\t\t %9.2f us (100%%)\n", irq ? "IRQ" : "Thread", + ns_to_usf(total)); +} + +/** + * timerlat_auto_analysis - Analyze the collected data + */ +void timerlat_auto_analysis(int irq_thresh, int thread_thresh) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + unsigned long long max_exit_from_idle = 0; + struct timerlat_aa_data *taa_data; + int max_exit_from_idle_cpu; + struct tep_handle *tep; + int cpu; + + /* bring stop tracing to the ns scale */ + irq_thresh = irq_thresh * 1000; + thread_thresh = thread_thresh * 1000; + + for (cpu = 0; cpu < taa_ctx->nr_cpus; cpu++) { + taa_data = timerlat_aa_get_data(taa_ctx, cpu); + + if (irq_thresh && taa_data->tlat_irq_latency >= irq_thresh) { + printf("## CPU %d hit stop tracing, analyzing it ##\n", cpu); + timerlat_thread_analysis(taa_data, cpu, irq_thresh, thread_thresh); + } else if (thread_thresh && (taa_data->tlat_thread_latency) >= thread_thresh) { + printf("## CPU %d hit stop tracing, analyzing it ##\n", cpu); + timerlat_thread_analysis(taa_data, cpu, irq_thresh, thread_thresh); + } + + if (taa_data->max_exit_idle_latency > max_exit_from_idle) { + max_exit_from_idle = taa_data->max_exit_idle_latency; + max_exit_from_idle_cpu = cpu; + } + + } + + if (max_exit_from_idle) { + printf("\n"); + printf("Max timerlat IRQ latency from idle: %.2f us in cpu %d\n", + ns_to_usf(max_exit_from_idle), max_exit_from_idle_cpu); + } + if (!taa_ctx->dump_tasks) + return; + + printf("\n"); + printf("Printing CPU tasks:\n"); + for (cpu = 0; cpu < taa_ctx->nr_cpus; cpu++) { + taa_data = timerlat_aa_get_data(taa_ctx, cpu); + tep = taa_ctx->tool->trace.tep; + + printf(" [%.3d] %24s:%llu", cpu, taa_data->current_comm, taa_data->current_pid); + + if (taa_data->kworker_func) + printf(" kworker:%s:%s", + tep_find_function(tep, taa_data->kworker) ? : "<...>", + tep_find_function(tep, taa_data->kworker_func)); + printf("\n"); + } + +} + +/* + * timerlat_aa_destroy_seqs - Destroy seq files used to store parsed data + */ +static void timerlat_aa_destroy_seqs(struct timerlat_aa_context *taa_ctx) +{ + struct timerlat_aa_data *taa_data; + int i; + + if (!taa_ctx->taa_data) + return; + + for (i = 0; i < taa_ctx->nr_cpus; i++) { + taa_data = timerlat_aa_get_data(taa_ctx, i); + + if (taa_data->prev_irqs_seq) { + trace_seq_destroy(taa_data->prev_irqs_seq); + free(taa_data->prev_irqs_seq); + } + + if (taa_data->nmi_seq) { + trace_seq_destroy(taa_data->nmi_seq); + free(taa_data->nmi_seq); + } + + if (taa_data->irqs_seq) { + trace_seq_destroy(taa_data->irqs_seq); + free(taa_data->irqs_seq); + } + + if (taa_data->softirqs_seq) { + trace_seq_destroy(taa_data->softirqs_seq); + free(taa_data->softirqs_seq); + } + + if (taa_data->threads_seq) { + trace_seq_destroy(taa_data->threads_seq); + free(taa_data->threads_seq); + } + + if (taa_data->stack_seq) { + trace_seq_destroy(taa_data->stack_seq); + free(taa_data->stack_seq); + } + } +} + +/* + * timerlat_aa_init_seqs - Init seq files used to store parsed information + * + * Instead of keeping data structures to store raw data, use seq files to + * store parsed data. + * + * Allocates and initialize seq files. + * + * Returns 0 on success, -1 otherwise. + */ +static int timerlat_aa_init_seqs(struct timerlat_aa_context *taa_ctx) +{ + struct timerlat_aa_data *taa_data; + int i; + + for (i = 0; i < taa_ctx->nr_cpus; i++) { + + taa_data = timerlat_aa_get_data(taa_ctx, i); + + taa_data->prev_irqs_seq = calloc(1, sizeof(*taa_data->prev_irqs_seq)); + if (!taa_data->prev_irqs_seq) + goto out_err; + + trace_seq_init(taa_data->prev_irqs_seq); + + taa_data->nmi_seq = calloc(1, sizeof(*taa_data->nmi_seq)); + if (!taa_data->nmi_seq) + goto out_err; + + trace_seq_init(taa_data->nmi_seq); + + taa_data->irqs_seq = calloc(1, sizeof(*taa_data->irqs_seq)); + if (!taa_data->irqs_seq) + goto out_err; + + trace_seq_init(taa_data->irqs_seq); + + taa_data->softirqs_seq = calloc(1, sizeof(*taa_data->softirqs_seq)); + if (!taa_data->softirqs_seq) + goto out_err; + + trace_seq_init(taa_data->softirqs_seq); + + taa_data->threads_seq = calloc(1, sizeof(*taa_data->threads_seq)); + if (!taa_data->threads_seq) + goto out_err; + + trace_seq_init(taa_data->threads_seq); + + taa_data->stack_seq = calloc(1, sizeof(*taa_data->stack_seq)); + if (!taa_data->stack_seq) + goto out_err; + + trace_seq_init(taa_data->stack_seq); + } + + return 0; + +out_err: + timerlat_aa_destroy_seqs(taa_ctx); + return -1; +} + +/* + * timerlat_aa_unregister_events - Unregister events used in the auto-analysis + */ +static void timerlat_aa_unregister_events(struct osnoise_tool *tool, int dump_tasks) +{ + tracefs_event_disable(tool->trace.inst, "osnoise", NULL); + + tep_unregister_event_handler(tool->trace.tep, -1, "osnoise", "nmi_noise", + timerlat_aa_nmi_handler, tool); + + tep_unregister_event_handler(tool->trace.tep, -1, "osnoise", "irq_noise", + timerlat_aa_irq_handler, tool); + + tep_unregister_event_handler(tool->trace.tep, -1, "osnoise", "softirq_noise", + timerlat_aa_softirq_handler, tool); + + tep_unregister_event_handler(tool->trace.tep, -1, "osnoise", "thread_noise", + timerlat_aa_thread_handler, tool); + + tep_unregister_event_handler(tool->trace.tep, -1, "ftrace", "kernel_stack", + timerlat_aa_stack_handler, tool); + if (!dump_tasks) + return; + + tracefs_event_disable(tool->trace.inst, "sched", "sched_switch"); + tep_unregister_event_handler(tool->trace.tep, -1, "sched", "sched_switch", + timerlat_aa_sched_switch_handler, tool); + + tracefs_event_disable(tool->trace.inst, "workqueue", "workqueue_execute_start"); + tep_unregister_event_handler(tool->trace.tep, -1, "workqueue", "workqueue_execute_start", + timerlat_aa_kworker_start_handler, tool); +} + +/* + * timerlat_aa_register_events - Register events used in the auto-analysis + * + * Returns 0 on success, -1 otherwise. + */ +static int timerlat_aa_register_events(struct osnoise_tool *tool, int dump_tasks) +{ + int retval; + + /* + * register auto-analysis handlers. + */ + retval = tracefs_event_enable(tool->trace.inst, "osnoise", NULL); + if (retval < 0 && !errno) { + err_msg("Could not find osnoise events\n"); + goto out_err; + } + + tep_register_event_handler(tool->trace.tep, -1, "osnoise", "nmi_noise", + timerlat_aa_nmi_handler, tool); + + tep_register_event_handler(tool->trace.tep, -1, "osnoise", "irq_noise", + timerlat_aa_irq_handler, tool); + + tep_register_event_handler(tool->trace.tep, -1, "osnoise", "softirq_noise", + timerlat_aa_softirq_handler, tool); + + tep_register_event_handler(tool->trace.tep, -1, "osnoise", "thread_noise", + timerlat_aa_thread_handler, tool); + + tep_register_event_handler(tool->trace.tep, -1, "ftrace", "kernel_stack", + timerlat_aa_stack_handler, tool); + + if (!dump_tasks) + return 0; + + /* + * Dump task events. + */ + retval = tracefs_event_enable(tool->trace.inst, "sched", "sched_switch"); + if (retval < 0 && !errno) { + err_msg("Could not find sched_switch\n"); + goto out_err; + } + + tep_register_event_handler(tool->trace.tep, -1, "sched", "sched_switch", + timerlat_aa_sched_switch_handler, tool); + + retval = tracefs_event_enable(tool->trace.inst, "workqueue", "workqueue_execute_start"); + if (retval < 0 && !errno) { + err_msg("Could not find workqueue_execute_start\n"); + goto out_err; + } + + tep_register_event_handler(tool->trace.tep, -1, "workqueue", "workqueue_execute_start", + timerlat_aa_kworker_start_handler, tool); + + return 0; + +out_err: + timerlat_aa_unregister_events(tool, dump_tasks); + return -1; +} + +/** + * timerlat_aa_destroy - Destroy timerlat auto-analysis + */ +void timerlat_aa_destroy(void) +{ + struct timerlat_aa_context *taa_ctx = timerlat_aa_get_ctx(); + + if (!taa_ctx) + return; + + if (!taa_ctx->taa_data) + goto out_ctx; + + timerlat_aa_unregister_events(taa_ctx->tool, taa_ctx->dump_tasks); + timerlat_aa_destroy_seqs(taa_ctx); + free(taa_ctx->taa_data); +out_ctx: + free(taa_ctx); +} + +/** + * timerlat_aa_init - Initialize timerlat auto-analysis + * + * Returns 0 on success, -1 otherwise. + */ +int timerlat_aa_init(struct osnoise_tool *tool, int nr_cpus, int dump_tasks) +{ + struct timerlat_aa_context *taa_ctx; + int retval; + + taa_ctx = calloc(1, sizeof(*taa_ctx)); + if (!taa_ctx) + return -1; + + __timerlat_aa_ctx = taa_ctx; + + taa_ctx->nr_cpus = nr_cpus; + taa_ctx->tool = tool; + taa_ctx->dump_tasks = dump_tasks; + + taa_ctx->taa_data = calloc(nr_cpus, sizeof(*taa_ctx->taa_data)); + if (!taa_ctx->taa_data) + goto out_err; + + retval = timerlat_aa_init_seqs(taa_ctx); + if (retval) + goto out_err; + + retval = timerlat_aa_register_events(tool, dump_tasks); + if (retval) + goto out_err; + + return 0; + +out_err: + timerlat_aa_destroy(); + return -1; +} |