[PATCH 02/26 v5] tracing: Add trace_seq_has_overflowed() and trace_handle_return()
From: "Steven Rostedt (Red Hat)"
Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.
Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.
Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.
This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.
Link: http://lkml.kernel.org/r/20141114011410.365183...@goodmis.org
Reviewed-by: Petr Mladek
Signed-off-by: Steven Rostedt
---
include/linux/ftrace_event.h | 11 ++
include/linux/trace_seq.h| 12 ++
include/trace/ftrace.h | 6 +-
kernel/trace/trace.c | 69 +++
kernel/trace/trace.h | 1 +
kernel/trace/trace_output.c | 416 +--
kernel/trace/trace_output.h | 16 +-
7 files changed, 231 insertions(+), 300 deletions(-)
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 28672e87e910..0bebb5c348b8 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -138,6 +138,17 @@ enum print_line_t {
TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
};
+/*
+ * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
+ * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
+ * simplifies those functions and keeps them in sync.
+ */
+static inline enum print_line_t trace_handle_return(struct trace_seq *s)
+{
+ return trace_seq_has_overflowed(s) ?
+ TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
+}
+
void tracing_generic_entry_update(struct trace_entry *entry,
unsigned long flags,
int pc);
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index ea6c9dea79e3..07eda413dfcf 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -40,6 +40,18 @@ trace_seq_buffer_ptr(struct trace_seq *s)
return s->buffer + s->len;
}
+/**
+ * trace_seq_has_overflowed - return true if the trace_seq took too much
+ * @s: trace sequence descriptor
+ *
+ * Returns true if too much data was added to the trace_seq and it is
+ * now full and will not take anymore.
+ */
+static inline bool trace_seq_has_overflowed(struct trace_seq *s)
+{
+ return s->full || s->len > PAGE_SIZE - 1;
+}
+
/*
* Currently only defined when tracing is enabled.
*/
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 26b4f2e13275..f13471b5d27a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -280,11 +280,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int
flags, \
if (ret)\
return ret; \
\
- ret = trace_seq_printf(s, print); \
- if (!ret) \
- return TRACE_TYPE_PARTIAL_LINE; \
+ trace_seq_printf(s, print); \
\
- return TRACE_TYPE_HANDLED; \
+ return trace_handle_return(s); \
} \
static struct trace_event_functions ftrace_event_type_funcs_##call = { \
.trace = ftrace_raw_output_##call, \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 44d561426700..3ce3c4ccfc94 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2649,24 +2649,21 @@ static enum print_line_t print_trace_fmt(struct
trace_iterator *iter)
event = ftrace_find_event(entry->type);
if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
- if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
- if (!trace_print_lat_context(iter))
- goto partial;
- } else {
- if (!trace_print_context(iter))
- goto partial;
- }
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ trace_print_lat_context(iter);
+ else
+ trace_print_context(iter);
}
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
[PATCH 02/26 v5] tracing: Add trace_seq_has_overflowed() and trace_handle_return()
From: Steven Rostedt (Red Hat) rost...@goodmis.org
Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.
Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.
Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.
This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.
Link: http://lkml.kernel.org/r/20141114011410.365183...@goodmis.org
Reviewed-by: Petr Mladek pmla...@suse.cz
Signed-off-by: Steven Rostedt rost...@goodmis.org
---
include/linux/ftrace_event.h | 11 ++
include/linux/trace_seq.h| 12 ++
include/trace/ftrace.h | 6 +-
kernel/trace/trace.c | 69 +++
kernel/trace/trace.h | 1 +
kernel/trace/trace_output.c | 416 +--
kernel/trace/trace_output.h | 16 +-
7 files changed, 231 insertions(+), 300 deletions(-)
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 28672e87e910..0bebb5c348b8 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -138,6 +138,17 @@ enum print_line_t {
TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
};
+/*
+ * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
+ * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
+ * simplifies those functions and keeps them in sync.
+ */
+static inline enum print_line_t trace_handle_return(struct trace_seq *s)
+{
+ return trace_seq_has_overflowed(s) ?
+ TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
+}
+
void tracing_generic_entry_update(struct trace_entry *entry,
unsigned long flags,
int pc);
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index ea6c9dea79e3..07eda413dfcf 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -40,6 +40,18 @@ trace_seq_buffer_ptr(struct trace_seq *s)
return s-buffer + s-len;
}
+/**
+ * trace_seq_has_overflowed - return true if the trace_seq took too much
+ * @s: trace sequence descriptor
+ *
+ * Returns true if too much data was added to the trace_seq and it is
+ * now full and will not take anymore.
+ */
+static inline bool trace_seq_has_overflowed(struct trace_seq *s)
+{
+ return s-full || s-len PAGE_SIZE - 1;
+}
+
/*
* Currently only defined when tracing is enabled.
*/
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 26b4f2e13275..f13471b5d27a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -280,11 +280,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int
flags, \
if (ret)\
return ret; \
\
- ret = trace_seq_printf(s, print); \
- if (!ret) \
- return TRACE_TYPE_PARTIAL_LINE; \
+ trace_seq_printf(s, print); \
\
- return TRACE_TYPE_HANDLED; \
+ return trace_handle_return(s); \
} \
static struct trace_event_functions ftrace_event_type_funcs_##call = { \
.trace = ftrace_raw_output_##call, \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 44d561426700..3ce3c4ccfc94 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2649,24 +2649,21 @@ static enum print_line_t print_trace_fmt(struct
trace_iterator *iter)
event = ftrace_find_event(entry-type);
if (trace_flags TRACE_ITER_CONTEXT_INFO) {
- if (iter-iter_flags TRACE_FILE_LAT_FMT) {
- if (!trace_print_lat_context(iter))
- goto partial;
- } else {
- if (!trace_print_context(iter))
- goto partial;
- }
+ if (iter-iter_flags TRACE_FILE_LAT_FMT)
+ trace_print_lat_context(iter);
+ else
+ trace_print_context(iter);
}
+ if (trace_seq_has_overflowed(s))
+
