Re: [PATCH 1/1] perf, tool: partial callgrap and time support in perf record

From: Namhyung Kim
Date: Sun Mar 15 2015 - 22:09:21 EST

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In reply to: kan . liang: "[PATCH 1/1] perf, tool: partial callgrap and time support in perf record"
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Hi Kan,

On Fri, Mar 13, 2015 at 02:18:07AM +0000, kan.liang@xxxxxxxxx wrote:
> From: Kan Liang <kan.liang@xxxxxxxxx>
>
> When multiple events are sampled it may not be needed to collect
> callgraphs for all of them. The sample sites are usually nearby, and
> it's enough to collect the callgraphs on a reference event (such as
> precise cycles or precise instructions). Similarly we also don't need
> fine grained time stamps on all events, as it's enough to have time
> stamps on the regular reference events. This patchkit adds the ability
> to turn off callgraphs and time stamps per event. This in term can
> reduce sampling overhead and the size of the perf.data (add some data)

Have you taken a look into group sampling feature?
(e.g. perf record -e '{ev1,ev2}:S')

Thanks,
Namhyung

>
> Here is an example.
>
> Collect callgrap and time for all events. The perf.data size is ~22M
>
> $ sudo ./perf record -e
> cpu/cpu-cycles,period=100000/,cpu/instructions,period=20000/p
> --call-graph fp ./tchain_edit
> [ perf record: Woken up 92 times to write data ]
> [ perf record: Captured and wrote 22.909 MB perf.data (249446 samples) ]
>
> Only collect callgrap and time on first event. The size is ~12M
>
> $ sudo ./perf record -e
> cpu/cpu-cycles,callgraph=1,time=1,period=100000/,
> cpu/instructions,callgraph=0,time=0,period=20000/p
> ./tchain_edit
> [ perf record: Woken up 50 times to write data ]
> [ perf record: Captured and wrote 12.489 MB perf.data (203267 samples) ]
>
> perf reprot result for the second event.
> Samples: 101K of event
> 'cpu/instructions,callgraph=0,time=0,period=20000/p', Event count
> (approx.): 2035000000
> Children Self Command Shared Object Symbol
> - 97.79% 0.00% tchain_edit libc-2.15.so [.]
> __libc_start_main
> __libc_start_main
> - 97.79% 0.00% tchain_edit tchain_edit [.] main
> main
> __libc_start_main
> - 97.79% 0.00% tchain_edit tchain_edit [.] f1
> f1
> main
> __libc_start_main
> - 97.79% 0.00% tchain_edit tchain_edit [.] f2
> f2
> f1
> main
> __libc_start_main
> - 97.79% 97.42% tchain_edit tchain_edit [.] f3
> f3
> f2
> f1
> main
> __libc_start_main
>
> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
> ---
> tools/perf/Documentation/perf-record.txt | 13 +++++++++
> tools/perf/builtin-record.c | 7 +++--
> tools/perf/perf.h | 2 ++
> tools/perf/util/evsel.c | 50 ++++++++++++++++++++++++++++++--
> tools/perf/util/parse-events.c | 33 +++++++++++++++++++++
> tools/perf/util/parse-events.h | 3 ++
> tools/perf/util/parse-events.l | 3 ++
> tools/perf/util/parse-options.c | 2 ++
> tools/perf/util/parse-options.h | 4 +++
> 9 files changed, 111 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index 355c4f5..8b3e76c0 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -45,6 +45,19 @@ OPTIONS
> param1 and param2 are defined as formats for the PMU in:
> /sys/bus/event_sources/devices/<pmu>/format/*
>
> + There are also some params which are not defined in .../<pmu>/format/*.
> + These params can be used to set event defaults.
> + Here is a list of the params.
> + - 'period': Set event sampling period
> + - 'callgraph': Disable/enable callgraph. Acceptable values are
> + 1 for FP mode, 2 for dwarf mode, 3 for LBR mode,
> + 0 for disabling callgraph.
> + - 'stack_size': user stack size for dwarf mode
> + - 'time': Disable/enable time stamping. Acceptable values are
> + 1 for enabling time stamping. 0 for disabling time stamping.
> + Note: If user explicitly sets options which conflict with the params,
> + the value set by the params will be overridden.
> +
> - a hardware breakpoint event in the form of '\mem:addr[/len][:access]'
> where addr is the address in memory you want to break in.
> Access is the memory access type (read, write, execute) it can
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 5a2ff51..bf536d1 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -795,10 +795,10 @@ struct option __record_options[] = {
> perf_evlist__parse_mmap_pages),
> OPT_BOOLEAN(0, "group", &record.opts.group,
> "put the counters into a counter group"),
> - OPT_CALLBACK_NOOPT('g', NULL, &record.opts,
> + OPT_CALLBACK_NOOPT_SET('g', NULL, &record.opts, &record.opts.callgraph_set,
> NULL, "enables call-graph recording" ,
> &record_callchain_opt),
> - OPT_CALLBACK(0, "call-graph", &record.opts,
> + OPT_CALLBACK_SET(0, "call-graph", &record.opts, &record.opts.callgraph_set,
> "mode[,dump_size]", record_callchain_help,
> &record_parse_callchain_opt),
> OPT_INCR('v', "verbose", &verbose,
> @@ -808,7 +808,8 @@ struct option __record_options[] = {
> "per thread counts"),
> OPT_BOOLEAN('d', "data", &record.opts.sample_address,
> "Sample addresses"),
> - OPT_BOOLEAN('T', "timestamp", &record.opts.sample_time, "Sample timestamps"),
> + OPT_BOOLEAN_SET('T', "timestamp", &record.opts.sample_time,
> + &record.opts.sample_time_set, "Sample timestamps"),
> OPT_BOOLEAN('P', "period", &record.opts.period, "Sample period"),
> OPT_BOOLEAN('n', "no-samples", &record.opts.no_samples,
> "don't sample"),
> diff --git a/tools/perf/perf.h b/tools/perf/perf.h
> index 1caa70a..72ebc91 100644
> --- a/tools/perf/perf.h
> +++ b/tools/perf/perf.h
> @@ -51,9 +51,11 @@ struct record_opts {
> bool sample_address;
> bool sample_weight;
> bool sample_time;
> + bool sample_time_set;
> bool period;
> bool sample_intr_regs;
> bool running_time;
> + bool callgraph_set;
> unsigned int freq;
> unsigned int mmap_pages;
> unsigned int user_freq;
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index bb4eff2..88a695b 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -614,10 +614,53 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
> struct perf_event_attr *attr = &evsel->attr;
> int track = evsel->tracking;
> bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
> + bool sample_time = opts->sample_time;
> + bool callgraph = callchain_param.enabled;
>
> attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
> attr->inherit = !opts->no_inherit;
>
> + /*
> + * If user doesn't explicitly set callgraph or time option,
> + * let event attribute decide.
> + */
> + if (!opts->callgraph_set) {
> + if (attr->sample_type & PERF_SAMPLE_CALLCHAIN) {
> + callgraph = true;
> + if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
> + callchain_param.record_mode = CALLCHAIN_DWARF;
> + if (attr->sample_stack_user)
> + callchain_param.dump_size = attr->sample_stack_user;
> + else
> + callchain_param.dump_size = 8192;
> + } else if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK)
> + callchain_param.record_mode = CALLCHAIN_LBR;
> + else
> + callchain_param.record_mode = CALLCHAIN_FP;
> + } else
> + callgraph = false;
> + }
> + /*
> + * Clear the bit which parse event may be set,
> + * Let perf_evsel__config_callgraph check and reset later.
> + */
> + attr->sample_type &= ~(PERF_SAMPLE_CALLCHAIN |
> + PERF_SAMPLE_STACK_USER |
> + PERF_SAMPLE_BRANCH_STACK);
> +
> +
> + if (!opts->sample_time_set) {
> + if (attr->sample_type & PERF_SAMPLE_TIME)
> + sample_time = true;
> + else
> + sample_time = false;
> + }
> + if (attr->sample_type & PERF_SAMPLE_TIME) {
> + attr->sample_type &= ~PERF_SAMPLE_TIME;
> + /* remove the size which add in perf_evsel__init */
> + evsel->sample_size -= sizeof(u64);
> + }
> +
> perf_evsel__set_sample_bit(evsel, IP);
> perf_evsel__set_sample_bit(evsel, TID);
>
> @@ -683,7 +726,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
> if (perf_evsel__is_function_event(evsel))
> evsel->attr.exclude_callchain_user = 1;
>
> - if (callchain_param.enabled && !evsel->no_aux_samples)
> + if (callgraph && !evsel->no_aux_samples)
> perf_evsel__config_callgraph(evsel, opts);
>
> if (opts->sample_intr_regs) {
> @@ -700,13 +743,14 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
> /*
> * When the user explicitely disabled time don't force it here.
> */
> - if (opts->sample_time &&
> + if (sample_time &&
> (!perf_missing_features.sample_id_all &&
> (!opts->no_inherit || target__has_cpu(&opts->target) || per_cpu)))
> perf_evsel__set_sample_bit(evsel, TIME);
>
> if (opts->raw_samples && !evsel->no_aux_samples) {
> - perf_evsel__set_sample_bit(evsel, TIME);
> + if (sample_time)
> + perf_evsel__set_sample_bit(evsel, TIME);
> perf_evsel__set_sample_bit(evsel, RAW);
> perf_evsel__set_sample_bit(evsel, CPU);
> }
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index fe07573..d0f30fb 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -17,6 +17,7 @@
> #include "parse-events-flex.h"
> #include "pmu.h"
> #include "thread_map.h"
> +#include "callchain.h"
>
> #define MAX_NAME_LEN 100
>
> @@ -570,6 +571,38 @@ do { \
> * attr->branch_sample_type = term->val.num;
> */
> break;
> + case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:
> + CHECK_TYPE_VAL(NUM);
> + switch (term->val.num) {
> + case CALLCHAIN_FP:
> + attr->sample_type |= PERF_SAMPLE_CALLCHAIN;
> + break;
> + case CALLCHAIN_DWARF:
> + attr->sample_type |= PERF_SAMPLE_CALLCHAIN |
> + PERF_SAMPLE_STACK_USER;
> + break;
> + case CALLCHAIN_LBR:
> + attr->sample_type |= PERF_SAMPLE_CALLCHAIN |
> + PERF_SAMPLE_BRANCH_STACK;
> + break;
> + case CALLCHAIN_NONE:
> + break;
> + default:
> + return -EINVAL;;
> + }
> + break;
> + case PARSE_EVENTS__TERM_TYPE_STACKSIZE:
> + CHECK_TYPE_VAL(NUM);
> + attr->sample_stack_user = term->val.num;
> + break;
> + case PARSE_EVENTS__TERM_TYPE_TIME:
> + CHECK_TYPE_VAL(NUM);
> +
> + if (term->val.num > 1)
> + return -EINVAL;
> + if (term->val.num == 1)
> + attr->sample_type |= PERF_SAMPLE_TIME;
> + break;
> case PARSE_EVENTS__TERM_TYPE_NAME:
> CHECK_TYPE_VAL(STR);
> break;
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index 52a2dda..2c16367 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -60,6 +60,9 @@ enum {
> PARSE_EVENTS__TERM_TYPE_NAME,
> PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD,
> PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE,
> + PARSE_EVENTS__TERM_TYPE_CALLGRAPH,
> + PARSE_EVENTS__TERM_TYPE_STACKSIZE,
> + PARSE_EVENTS__TERM_TYPE_TIME,
> };
>
> struct parse_events_term {
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 94eacb6..655306b 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -151,6 +151,9 @@ config2 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG2); }
> name { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NAME); }
> period { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD); }
> branch_type { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE); }
> +callgraph { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CALLGRAPH); }
> +stack_size { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_STACKSIZE); }
> +time { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_TIME); }
> , { return ','; }
> "/" { BEGIN(INITIAL); return '/'; }
> {name_minus} { return str(yyscanner, PE_NAME); }
> diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
> index 1457d66..3786abb 100644
> --- a/tools/perf/util/parse-options.c
> +++ b/tools/perf/util/parse-options.c
> @@ -123,6 +123,8 @@ static int get_value(struct parse_opt_ctx_t *p,
> return 0;
>
> case OPTION_CALLBACK:
> + if (opt->set)
> + *(bool *)opt->set = true;
> if (unset)
> return (*opt->callback)(opt, NULL, 1) ? (-1) : 0;
> if (opt->flags & PARSE_OPT_NOARG)
> diff --git a/tools/perf/util/parse-options.h b/tools/perf/util/parse-options.h
> index 97b153f..20d0d29 100644
> --- a/tools/perf/util/parse-options.h
> +++ b/tools/perf/util/parse-options.h
> @@ -126,8 +126,12 @@ struct option {
> { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), .argh = "time", .help = (h), .callback = parse_opt_approxidate_cb }
> #define OPT_CALLBACK(s, l, v, a, h, f) \
> { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f) }
> +#define OPT_CALLBACK_SET(s, l, v, os, a, h, f) \
> + { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .set = check_vtype(os, bool *) }
> #define OPT_CALLBACK_NOOPT(s, l, v, a, h, f) \
> { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .flags = PARSE_OPT_NOARG }
> +#define OPT_CALLBACK_NOOPT_SET(s, l, v, os, a, h, f) \
> + { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .flags = PARSE_OPT_NOARG, .set = check_vtype(os, bool *) }
> #define OPT_CALLBACK_DEFAULT(s, l, v, a, h, f, d) \
> { .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .defval = (intptr_t)d, .flags = PARSE_OPT_LASTARG_DEFAULT }
> #define OPT_CALLBACK_DEFAULT_NOOPT(s, l, v, a, h, f, d) \
> --
> 1.7.11.7
>
> --
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Next message: Jaehoon Chung: "Re: [PATCH v4 1/4] mmc: dw_mmc: Don't try to enable the CD until we're sure we're not deferring"
Previous message: Stephen Rothwell: "linux-next: manual merge of the net-next tree with the net tree"
In reply to: kan . liang: "[PATCH 1/1] perf, tool: partial callgrap and time support in perf record"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]