From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <zanussi@kernel.org>,
linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v6 2/5] tracing: Add .percent suffix option to histogram values
Date: Wed, 19 Oct 2022 00:48:51 +0900 [thread overview]
Message-ID: <166610813077.56030.4238090506973562347.stgit@devnote2> (raw)
In-Reply-To: <166610811353.56030.10023036046735082272.stgit@devnote2>
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add .percent suffix option to show the histogram values in percentage.
This feature is useful when we need yo undersntand the overall trend
for the histograms of large values.
E.g. this shows the runtime percentage for each tasks.
------
# cd /sys/kernel/debug/tracing/
# echo hist:keys=pid:vals=hitcount,runtime.percent:sort=pid > \
events/sched/sched_stat_runtime/trigger
# sleep 10
# cat events/sched/sched_stat_runtime/hist
# event histogram
#
# trigger info: hist:keys=pid:vals=hitcount,runtime.percent:sort=pid:size=2048 [active]
#
{ pid: 8 } hitcount: 7 runtime (%): 4.14
{ pid: 14 } hitcount: 5 runtime (%): 3.69
{ pid: 16 } hitcount: 11 runtime (%): 3.41
{ pid: 61 } hitcount: 41 runtime (%): 19.75
{ pid: 65 } hitcount: 4 runtime (%): 1.48
{ pid: 70 } hitcount: 6 runtime (%): 3.60
{ pid: 72 } hitcount: 2 runtime (%): 1.10
{ pid: 144 } hitcount: 10 runtime (%): 32.01
{ pid: 151 } hitcount: 8 runtime (%): 22.66
{ pid: 152 } hitcount: 2 runtime (%): 8.10
Totals:
Hits: 96
Entries: 10
Dropped: 0
-----
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
---
kernel/trace/trace.c | 3 +
kernel/trace/trace_events_hist.c | 90 ++++++++++++++++++++++++++++++++------
2 files changed, 78 insertions(+), 15 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index aed7ea6e6045..e868f8bd06ec 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5715,7 +5715,8 @@ static const char readme_msg[] =
"\t .syscall display a syscall id as a syscall name\n"
"\t .log2 display log2 value rather than raw number\n"
"\t .buckets=size display values in groups of size rather than raw number\n"
- "\t .usecs display a common_timestamp in microseconds\n\n"
+ "\t .usecs display a common_timestamp in microseconds\n"
+ "\t .percent display a number of percentage value\n\n"
"\t The 'pause' parameter can be used to pause an existing hist\n"
"\t trigger or to start a hist trigger but not log any events\n"
"\t until told to do so. 'continue' can be used to start or\n"
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 13bb7ec45836..65691608a390 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -506,6 +506,7 @@ enum hist_field_flags {
HIST_FIELD_FL_ALIAS = 1 << 16,
HIST_FIELD_FL_BUCKET = 1 << 17,
HIST_FIELD_FL_CONST = 1 << 18,
+ HIST_FIELD_FL_PERCENT = 1 << 19,
};
struct var_defs {
@@ -1707,6 +1708,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field)
flags_str = "buckets";
else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
flags_str = "usecs";
+ else if (hist_field->flags & HIST_FIELD_FL_PERCENT)
+ flags_str = "percent";
return flags_str;
}
@@ -2315,6 +2318,10 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
if (ret || !(*buckets))
goto error;
*flags |= HIST_FIELD_FL_BUCKET;
+ } else if (strncmp(modifier, "percent", 7) == 0) {
+ if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY))
+ goto error;
+ *flags |= HIST_FIELD_FL_PERCENT;
} else {
error:
hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier));
@@ -5288,33 +5295,69 @@ static void hist_trigger_print_key(struct seq_file *m,
seq_puts(m, "}");
}
+/* Get the 100 times of the percentage of @val in @total */
+static inline unsigned int __get_percentage(u64 val, u64 total)
+{
+ if (!total)
+ goto div0;
+
+ if (val < (U64_MAX / 10000))
+ return (unsigned int)div64_ul(val * 10000, total);
+
+ total = div64_u64(total, 10000);
+ if (!total)
+ goto div0;
+
+ return (unsigned int)div64_ul(val, total);
+div0:
+ return val ? UINT_MAX : 0;
+}
+
+static void hist_trigger_print_val(struct seq_file *m, unsigned int idx,
+ const char *field_name, unsigned long flags,
+ u64 *totals, struct tracing_map_elt *elt)
+{
+ u64 val = tracing_map_read_sum(elt, idx);
+ unsigned int pc;
+
+ if (flags & HIST_FIELD_FL_PERCENT) {
+ pc = __get_percentage(val, totals[idx]);
+ if (pc == UINT_MAX)
+ seq_printf(m, " %s (%%):[ERROR]", field_name);
+ else
+ seq_printf(m, " %s (%%): %3u.%02u", field_name,
+ pc / 100, pc % 100);
+ } else if (flags & HIST_FIELD_FL_HEX) {
+ seq_printf(m, " %s: %10llx", field_name, val);
+ } else {
+ seq_printf(m, " %s: %10llu", field_name, val);
+ }
+}
+
static void hist_trigger_entry_print(struct seq_file *m,
struct hist_trigger_data *hist_data,
+ u64 *totals,
void *key,
struct tracing_map_elt *elt)
{
const char *field_name;
- unsigned int i;
+ unsigned int i = HITCOUNT_IDX;
+ unsigned long flags;
hist_trigger_print_key(m, hist_data, key, elt);
- seq_printf(m, " hitcount: %10llu",
- tracing_map_read_sum(elt, HITCOUNT_IDX));
+ /* At first, show the raw hitcount always */
+ hist_trigger_print_val(m, i, "hitcount", 0, totals, elt);
for (i = 1; i < hist_data->n_vals; i++) {
field_name = hist_field_name(hist_data->fields[i], 0);
+ flags = hist_data->fields[i]->flags;
- if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR ||
- hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR)
+ if (flags & HIST_FIELD_FL_VAR || flags & HIST_FIELD_FL_EXPR)
continue;
- if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
- seq_printf(m, " %s: %10llx", field_name,
- tracing_map_read_sum(elt, i));
- } else {
- seq_printf(m, " %s: %10llu", field_name,
- tracing_map_read_sum(elt, i));
- }
+ seq_puts(m, " ");
+ hist_trigger_print_val(m, i, field_name, flags, totals, elt);
}
print_actions(m, hist_data, elt);
@@ -5327,7 +5370,8 @@ static int print_entries(struct seq_file *m,
{
struct tracing_map_sort_entry **sort_entries = NULL;
struct tracing_map *map = hist_data->map;
- int i, n_entries;
+ int i, j, n_entries;
+ u64 *totals = NULL;
n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
hist_data->n_sort_keys,
@@ -5335,11 +5379,29 @@ static int print_entries(struct seq_file *m,
if (n_entries < 0)
return n_entries;
+ for (j = 0; j < hist_data->n_vals; j++) {
+ if (!(hist_data->fields[j]->flags & HIST_FIELD_FL_PERCENT))
+ continue;
+ if (!totals) {
+ totals = kcalloc(hist_data->n_vals, sizeof(u64),
+ GFP_KERNEL);
+ if (!totals) {
+ n_entries = -ENOMEM;
+ goto out;
+ }
+ }
+ for (i = 0; i < n_entries; i++)
+ totals[j] += tracing_map_read_sum(
+ sort_entries[i]->elt, j);
+ }
+
for (i = 0; i < n_entries; i++)
- hist_trigger_entry_print(m, hist_data,
+ hist_trigger_entry_print(m, hist_data, totals,
sort_entries[i]->key,
sort_entries[i]->elt);
+ kfree(totals);
+out:
tracing_map_destroy_sort_entries(sort_entries, n_entries);
return n_entries;
next prev parent reply other threads:[~2022-10-18 15:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 15:48 [PATCH v6 0/5] tracing/hist: Add percentage histogram suffixes Masami Hiramatsu (Google)
2022-10-18 15:48 ` [PATCH v6 1/5] tracing: Allow multiple hitcount values in histograms Masami Hiramatsu (Google)
2022-10-18 15:48 ` Masami Hiramatsu (Google) [this message]
2022-10-18 15:48 ` [PATCH v6 3/5] tracing: Add .graph suffix option to histogram value Masami Hiramatsu (Google)
2022-10-18 15:49 ` [PATCH v6 4/5] tracing: Add nohitcount option for suppressing display of raw hitcount Masami Hiramatsu (Google)
2022-10-18 15:49 ` [PATCH v6 5/5] tracing: docs: Update histogram doc for .percent/.graph and 'nohitcount' Masami Hiramatsu (Google)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=166610813077.56030.4238090506973562347.stgit@devnote2 \
--to=mhiramat@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=zanussi@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.