| From 48e6bf50c935e33015ef25319b8b8ee15169e128 Mon Sep 17 00:00:00 2001 |
| From: Tom Zanussi <tom.zanussi@linux.intel.com> |
| Date: Mon, 15 Jan 2018 20:52:03 -0600 |
| Subject: [PATCH 1776/1795] tracing: Add cpu field for hist triggers |
| |
| A common key to use in a histogram is the cpuid - add a new cpu |
| 'synthetic' field named 'cpu' for that purpose. |
| |
| Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com |
| |
| Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> |
| Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
| (cherry picked from commit 8b7622bf94a44b3f912e6492bf500e86171300b8) |
| Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp> |
| Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> |
| --- |
| Documentation/trace/histogram.txt | 15 +++++++++++++++ |
| kernel/trace/trace_events_hist.c | 28 +++++++++++++++++++++++++++- |
| 2 files changed, 42 insertions(+), 1 deletion(-) |
| |
| diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt |
| index 25c94730d3fe..be612ca79455 100644 |
| --- a/Documentation/trace/histogram.txt |
| +++ b/Documentation/trace/histogram.txt |
| @@ -172,6 +172,21 @@ |
| The examples below provide a more concrete illustration of the |
| concepts and typical usage patterns discussed above. |
| |
| + 'special' event fields |
| + ------------------------ |
| + |
| + There are a number of 'special event fields' available for use as |
| + keys or values in a hist trigger. These look like and behave as if |
| + they were actual event fields, but aren't really part of the event's |
| + field definition or format file. They are however available for any |
| + event, and can be used anywhere an actual event field could be. |
| + They are: |
| + |
| + common_timestamp u64 - timestamp (from ring buffer) associated |
| + with the event, in nanoseconds. May be |
| + modified by .usecs to have timestamps |
| + interpreted as microseconds. |
| + cpu int - the cpu on which the event occurred. |
| |
| 6.2 'hist' trigger examples |
| --------------------------- |
| diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c |
| index 7e88daae85b6..98be6ad883eb 100644 |
| --- a/kernel/trace/trace_events_hist.c |
| +++ b/kernel/trace/trace_events_hist.c |
| @@ -227,6 +227,7 @@ enum hist_field_flags { |
| HIST_FIELD_FL_VAR = 1 << 12, |
| HIST_FIELD_FL_EXPR = 1 << 13, |
| HIST_FIELD_FL_VAR_REF = 1 << 14, |
| + HIST_FIELD_FL_CPU = 1 << 15, |
| }; |
| |
| struct var_defs { |
| @@ -1164,6 +1165,16 @@ static u64 hist_field_timestamp(struct hist_field *hist_field, |
| return ts; |
| } |
| |
| +static u64 hist_field_cpu(struct hist_field *hist_field, |
| + struct tracing_map_elt *elt, |
| + struct ring_buffer_event *rbe, |
| + void *event) |
| +{ |
| + int cpu = smp_processor_id(); |
| + |
| + return cpu; |
| +} |
| + |
| static struct hist_field * |
| check_field_for_var_ref(struct hist_field *hist_field, |
| struct hist_trigger_data *var_data, |
| @@ -1602,6 +1613,8 @@ static const char *hist_field_name(struct hist_field *field, |
| field_name = hist_field_name(field->operands[0], ++level); |
| else if (field->flags & HIST_FIELD_FL_TIMESTAMP) |
| field_name = "common_timestamp"; |
| + else if (field->flags & HIST_FIELD_FL_CPU) |
| + field_name = "cpu"; |
| else if (field->flags & HIST_FIELD_FL_EXPR || |
| field->flags & HIST_FIELD_FL_VAR_REF) { |
| if (field->system) { |
| @@ -2109,6 +2122,15 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, |
| goto out; |
| } |
| |
| + if (flags & HIST_FIELD_FL_CPU) { |
| + hist_field->fn = hist_field_cpu; |
| + hist_field->size = sizeof(int); |
| + hist_field->type = kstrdup("unsigned int", GFP_KERNEL); |
| + if (!hist_field->type) |
| + goto free; |
| + goto out; |
| + } |
| + |
| if (WARN_ON_ONCE(!field)) |
| goto out; |
| |
| @@ -2345,7 +2367,9 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, |
| hist_data->enable_timestamps = true; |
| if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS) |
| hist_data->attrs->ts_in_usecs = true; |
| - } else { |
| + } else if (strcmp(field_name, "cpu") == 0) |
| + *flags |= HIST_FIELD_FL_CPU; |
| + else { |
| field = trace_find_event_field(file->event_call, field_name); |
| if (!field || !field->size) { |
| field = ERR_PTR(-EINVAL); |
| @@ -4619,6 +4643,8 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) |
| |
| if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP) |
| seq_puts(m, "common_timestamp"); |
| + else if (hist_field->flags & HIST_FIELD_FL_CPU) |
| + seq_puts(m, "cpu"); |
| else if (field_name) { |
| if (hist_field->flags & HIST_FIELD_FL_VAR_REF) |
| seq_putc(m, '$'); |
| -- |
| 2.19.0 |
| |