From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [for-next][PATCH 3/4] tracing: Show number of constants profiled in likely profiler
Date: Thu, 19 Jan 2017 09:00:12 -0500 [thread overview]
Message-ID: <20170119140037.369366191@goodmis.org> (raw)
In-Reply-To: 20170119140009.735308162@goodmis.org
[-- Attachment #1: 0003-tracing-Show-number-of-constants-profiled-in-likely-.patch --]
[-- Type: text/plain, Size: 5950 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Now that constants are traced, it is useful to see the number of constants
that are traced in the likely/unlikely profiler in order to know if they
should be ignored or not.
The likely/unlikely will display a number after the "correct" number if a
"constant" count exists.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/compiler.h | 15 ++++++----
kernel/trace/trace_branch.c | 68 ++++++++++++++++++++++++++++++++++++---------
2 files changed, 65 insertions(+), 18 deletions(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index bbbe1570de1c..a73cc9afa784 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -101,13 +101,18 @@ struct ftrace_branch_data {
};
};
+struct ftrace_likely_data {
+ struct ftrace_branch_data data;
+ unsigned long constant;
+};
+
/*
* Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
* to disable branch tracing on a per file basis.
*/
#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
&& !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
-void ftrace_likely_update(struct ftrace_branch_data *f, int val,
+void ftrace_likely_update(struct ftrace_likely_data *f, int val,
int expect, int is_constant);
#define likely_notrace(x) __builtin_expect(!!(x), 1)
@@ -115,13 +120,13 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val,
#define __branch_check__(x, expect, is_constant) ({ \
int ______r; \
- static struct ftrace_branch_data \
+ static struct ftrace_likely_data \
__attribute__((__aligned__(4))) \
__attribute__((section("_ftrace_annotated_branch"))) \
______f = { \
- .func = __func__, \
- .file = __FILE__, \
- .line = __LINE__, \
+ .data.func = __func__, \
+ .data.file = __FILE__, \
+ .data.line = __LINE__, \
}; \
______r = __builtin_expect(!!(x), expect); \
ftrace_likely_update(&______f, ______r, \
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 7afe426ea528..fd483d74f8e1 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -200,25 +200,27 @@ void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
}
#endif /* CONFIG_BRANCH_TRACER */
-void ftrace_likely_update(struct ftrace_branch_data *f, int val,
+void ftrace_likely_update(struct ftrace_likely_data *f, int val,
int expect, int is_constant)
{
/* A constant is always correct */
- if (is_constant)
+ if (is_constant) {
+ f->constant++;
val = expect;
+ }
/*
* I would love to have a trace point here instead, but the
* trace point code is so inundated with unlikely and likely
* conditions that the recursive nightmare that exists is too
* much to try to get working. At least for now.
*/
- trace_likely_condition(f, val, expect);
+ trace_likely_condition(&f->data, val, expect);
/* FIXME: Make this atomic! */
if (val == expect)
- f->correct++;
+ f->data.correct++;
else
- f->incorrect++;
+ f->data.incorrect++;
}
EXPORT_SYMBOL(ftrace_likely_update);
@@ -249,29 +251,60 @@ static inline long get_incorrect_percent(struct ftrace_branch_data *p)
return percent;
}
-static int branch_stat_show(struct seq_file *m, void *v)
+static const char *branch_stat_process_file(struct ftrace_branch_data *p)
{
- struct ftrace_branch_data *p = v;
const char *f;
- long percent;
/* Only print the file, not the path */
f = p->file + strlen(p->file);
while (f >= p->file && *f != '/')
f--;
- f++;
+ return ++f;
+}
+
+static void branch_stat_show(struct seq_file *m,
+ struct ftrace_branch_data *p, const char *f)
+{
+ long percent;
/*
* The miss is overlayed on correct, and hit on incorrect.
*/
percent = get_incorrect_percent(p);
- seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect);
if (percent < 0)
seq_puts(m, " X ");
else
seq_printf(m, "%3ld ", percent);
+
seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
+}
+
+static int branch_stat_show_normal(struct seq_file *m,
+ struct ftrace_branch_data *p, const char *f)
+{
+ seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect);
+ branch_stat_show(m, p, f);
+ return 0;
+}
+
+static int annotate_branch_stat_show(struct seq_file *m, void *v)
+{
+ struct ftrace_likely_data *p = v;
+ const char *f;
+ int l;
+
+ f = branch_stat_process_file(&p->data);
+
+ if (!p->constant)
+ return branch_stat_show_normal(m, &p->data, f);
+
+ l = snprintf(NULL, 0, "/%lu", p->constant);
+ l = l > 8 ? 0 : 8 - l;
+
+ seq_printf(m, "%8lu/%lu %*lu ",
+ p->data.correct, p->constant, l, p->data.incorrect);
+ branch_stat_show(m, &p->data, f);
return 0;
}
@@ -283,7 +316,7 @@ static void *annotated_branch_stat_start(struct tracer_stat *trace)
static void *
annotated_branch_stat_next(void *v, int idx)
{
- struct ftrace_branch_data *p = v;
+ struct ftrace_likely_data *p = v;
++p;
@@ -332,7 +365,7 @@ static struct tracer_stat annotated_branch_stats = {
.stat_next = annotated_branch_stat_next,
.stat_cmp = annotated_branch_stat_cmp,
.stat_headers = annotated_branch_stat_headers,
- .stat_show = branch_stat_show
+ .stat_show = annotate_branch_stat_show
};
__init static int init_annotated_branch_stats(void)
@@ -383,12 +416,21 @@ all_branch_stat_next(void *v, int idx)
return p;
}
+static int all_branch_stat_show(struct seq_file *m, void *v)
+{
+ struct ftrace_branch_data *p = v;
+ const char *f;
+
+ f = branch_stat_process_file(p);
+ return branch_stat_show_normal(m, p, f);
+}
+
static struct tracer_stat all_branch_stats = {
.name = "branch_all",
.stat_start = all_branch_stat_start,
.stat_next = all_branch_stat_next,
.stat_headers = all_branch_stat_headers,
- .stat_show = branch_stat_show
+ .stat_show = all_branch_stat_show
};
__init static int all_annotated_branch_stats(void)
--
2.10.2
next prev parent reply other threads:[~2017-01-19 14:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-19 14:00 [for-next][PATCH 0/4] tracing: Updates for v4.11 Steven Rostedt
2017-01-19 14:00 ` [for-next][PATCH 1/4] uprobe: Find last occurrence of : when parsing uprobe PATH:OFFSET Steven Rostedt
2017-01-19 14:00 ` [for-next][PATCH 2/4] tracing: Process constants for (un)likely() profiler Steven Rostedt
2017-01-19 14:00 ` Steven Rostedt [this message]
2017-01-19 14:00 ` [for-next][PATCH 4/4] tracing: Add the constant count for branch tracer Steven Rostedt
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