From: Daniel Bristot de Oliveira Date: Tue, 6 Jun 2023 16:12:19 +0000 (+0200) Subject: rtla/timerlat: Give timerlat auto analysis its own instance X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c66552be9ec9f83705a911cb2219cffc39c42a0c;p=linux.git rtla/timerlat: Give timerlat auto analysis its own instance Currently, the auto-analysis is attached to the timerlat top instance. The idea was to avoid creating another instance just for that, so one instance could be reused. The drawback is that, by doing so, the auto-analysis run for the entire session, consuming CPU time. On my 24 box CPUs for timerlat with a 100 us period consumed 50 % with auto analysis, but only 16 % without. By creating an instance for auto-analysis, we can keep the processing stopped until a stop tracing condition is hit. Once it happens, timerlat auto-analysis can use its own trace instance to parse only the end of the trace. By doing so, auto-analysis stop consuming cpu time when it is not needed. If the --aa-only is passed, the timerlat top instance is reused for auto analysis. Link: https://lkml.kernel.org/r/346b7168c1bae552a415715ec6d23c129a43bdb7.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google) --- diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c index 1843fff66da5b..e0ffe69c271c6 100644 --- a/tools/tracing/rtla/src/timerlat_aa.c +++ b/tools/tracing/rtla/src/timerlat_aa.c @@ -8,6 +8,7 @@ #include "utils.h" #include "osnoise.h" #include "timerlat.h" +#include enum timelat_state { TIMERLAT_INIT = 0, @@ -233,7 +234,7 @@ static int timerlat_aa_thread_latency(struct timerlat_aa_data *taa_data, * * Returns 0 on success, -1 otherwise. */ -int timerlat_aa_handler(struct trace_seq *s, struct tep_record *record, +static 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(); @@ -665,6 +666,25 @@ print_total: ns_to_usf(total)); } +static int timerlat_auto_analysis_collect_trace(struct timerlat_aa_context *taa_ctx) +{ + struct trace_instance *trace = &taa_ctx->tool->trace; + int retval; + + retval = tracefs_iterate_raw_events(trace->tep, + trace->inst, + NULL, + 0, + collect_registered_events, + trace); + if (retval < 0) { + err_msg("Error iterating on events\n"); + return 0; + } + + return 1; +} + /** * timerlat_auto_analysis - Analyze the collected data */ @@ -677,6 +697,8 @@ void timerlat_auto_analysis(int irq_thresh, int thread_thresh) struct tep_handle *tep; int cpu; + timerlat_auto_analysis_collect_trace(taa_ctx); + /* bring stop tracing to the ns scale */ irq_thresh = irq_thresh * 1000; thread_thresh = thread_thresh * 1000; @@ -838,6 +860,10 @@ out_err: */ static void timerlat_aa_unregister_events(struct osnoise_tool *tool, int dump_tasks) { + + tep_unregister_event_handler(tool->trace.tep, -1, "ftrace", "timerlat", + timerlat_aa_handler, tool); + tracefs_event_disable(tool->trace.inst, "osnoise", NULL); tep_unregister_event_handler(tool->trace.tep, -1, "osnoise", "nmi_noise", @@ -875,6 +901,10 @@ static int timerlat_aa_register_events(struct osnoise_tool *tool, int dump_tasks { int retval; + tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat", + timerlat_aa_handler, tool); + + /* * register auto-analysis handlers. */ @@ -955,8 +985,9 @@ out_ctx: * * Returns 0 on success, -1 otherwise. */ -int timerlat_aa_init(struct osnoise_tool *tool, int nr_cpus, int dump_tasks) +int timerlat_aa_init(struct osnoise_tool *tool, int dump_tasks) { + int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); struct timerlat_aa_context *taa_ctx; int retval; diff --git a/tools/tracing/rtla/src/timerlat_aa.h b/tools/tracing/rtla/src/timerlat_aa.h index d4f6ca7e342a1..cea4bb1531a89 100644 --- a/tools/tracing/rtla/src/timerlat_aa.h +++ b/tools/tracing/rtla/src/timerlat_aa.h @@ -3,10 +3,7 @@ * Copyright (C) 2023 Red Hat Inc, Daniel Bristot de Oliveira */ -int timerlat_aa_init(struct osnoise_tool *tool, int nr_cpus, int dump_task); +int timerlat_aa_init(struct osnoise_tool *tool, int dump_task); void timerlat_aa_destroy(void); -int timerlat_aa_handler(struct trace_seq *s, struct tep_record *record, - struct tep_event *event, void *context); - void timerlat_auto_analysis(int irq_thresh, int thread_thresh); diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c index f0c6d9735e2ad..d6b5a382569ec 100644 --- a/tools/tracing/rtla/src/timerlat_top.c +++ b/tools/tracing/rtla/src/timerlat_top.c @@ -156,9 +156,6 @@ timerlat_top_handler(struct trace_seq *s, struct tep_record *record, timerlat_top_update(top, cpu, thread, latency); } - if (!params->no_aa) - timerlat_aa_handler(s, record, event, context); - return 0; } @@ -644,7 +641,6 @@ static struct osnoise_tool { struct osnoise_tool *top; int nr_cpus; - int retval; nr_cpus = sysconf(_SC_NPROCESSORS_CONF); @@ -661,16 +657,6 @@ static struct osnoise_tool tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat", timerlat_top_handler, top); - /* - * If no auto analysis, we are ready. - */ - if (params->no_aa) - return top; - - retval = timerlat_aa_init(top, nr_cpus, params->dump_tasks); - if (retval) - goto out_err; - return top; out_err: @@ -702,6 +688,7 @@ int timerlat_top_main(int argc, char *argv[]) struct timerlat_top_params *params; struct osnoise_tool *record = NULL; struct osnoise_tool *top = NULL; + struct osnoise_tool *aa = NULL; struct trace_instance *trace; int dma_latency_fd = -1; int return_value = 1; @@ -774,6 +761,35 @@ int timerlat_top_main(int argc, char *argv[]) trace_instance_start(&record->trace); } + if (!params->no_aa) { + if (params->aa_only) { + /* as top is not used for display, use it for aa */ + aa = top; + } else { + /* otherwise, a new instance is needed */ + aa = osnoise_init_tool("timerlat_aa"); + if (!aa) + goto out_top; + } + + retval = timerlat_aa_init(aa, params->dump_tasks); + if (retval) { + err_msg("Failed to enable the auto analysis instance\n"); + goto out_top; + } + + /* if it is re-using the main instance, there is no need to start it */ + if (aa != top) { + retval = enable_timerlat(&aa->trace); + if (retval) { + err_msg("Failed to enable timerlat tracer\n"); + goto out_top; + } + + trace_instance_start(&aa->trace); + } + } + top->start_time = time(NULL); timerlat_top_set_signals(params); @@ -829,13 +845,15 @@ int timerlat_top_main(int argc, char *argv[]) } out_top: + timerlat_aa_destroy(); if (dma_latency_fd >= 0) close(dma_latency_fd); trace_events_destroy(&record->trace, params->events); params->events = NULL; out_free: timerlat_free_top(top->data); - timerlat_aa_destroy(); + if (aa && aa != top) + osnoise_destroy_tool(aa); osnoise_destroy_tool(record); osnoise_destroy_tool(top); free(params);