tracing/ftrace: change the type of the print_line callback
We need a kind of disambiguation when a print_line callback
returns 0.
_There is not enough space to print all the entry.
Please flush the seq and retry.
_I can't handle this type of entry
This patch changes the type of this callback for better information.
Also some changes have been made in this V2.
_ Only relay to default functions after the print_line callback fails.
_ This patch doesn't fix the issue with the broken pipe (see patch 2/4 for that)
Some things are still in discussion:
_ Find better names for the enum print_line_t values
_ Change the type of print_trace_line into boolean.
Patches to change that can be sent later.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ed9e47c..b38a4bb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1250,7 +1250,7 @@
trace_seq_putc(s, '\n');
}
-static int
+static enum print_line_t
print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
{
struct trace_seq *s = &iter->seq;
@@ -1267,7 +1267,7 @@
unsigned state;
if (entry->type == TRACE_CONT)
- return 1;
+ return TRACE_TYPE_HANDLED;
next_entry = find_next_entry(iter, NULL, &next_ts);
if (!next_entry)
@@ -1357,10 +1357,10 @@
default:
trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_trace_fmt(struct trace_iterator *iter)
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1376,7 +1376,7 @@
entry = iter->ent;
if (entry->type == TRACE_CONT)
- return 1;
+ return TRACE_TYPE_HANDLED;
comm = trace_find_cmdline(iter->ent->pid);
@@ -1386,13 +1386,13 @@
ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
switch (entry->type) {
case TRACE_FN: {
@@ -1400,12 +1400,12 @@
ret = seq_print_ip_sym(s, field->ip, sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
field->parent_ip) {
ret = trace_seq_printf(s, " <-");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
if (kretprobed(field->parent_ip))
ret = trace_seq_puts(s, KRETPROBE_MSG);
else
@@ -1413,11 +1413,11 @@
field->parent_ip,
sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "\n");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_CTX:
@@ -1439,7 +1439,7 @@
field->next_prio,
T);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_SPECIAL: {
@@ -1450,7 +1450,7 @@
field->arg2,
field->arg3);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_STACK: {
@@ -1460,16 +1460,16 @@
if (i) {
ret = trace_seq_puts(s, " <= ");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
ret = seq_print_ip_sym(s, field->caller[i],
sym_flags);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_puts(s, "\n");
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_PRINT: {
@@ -1482,10 +1482,10 @@
break;
}
}
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_raw_fmt(struct trace_iterator *iter)
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
@@ -1495,12 +1495,12 @@
entry = iter->ent;
if (entry->type == TRACE_CONT)
- return 1;
+ return TRACE_TYPE_HANDLED;
ret = trace_seq_printf(s, "%d %d %llu ",
entry->pid, iter->cpu, iter->ts);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
switch (entry->type) {
case TRACE_FN: {
@@ -1510,7 +1510,7 @@
field->ip,
field->parent_ip);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_CTX:
@@ -1533,7 +1533,7 @@
field->next_prio,
T);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_SPECIAL:
@@ -1545,7 +1545,7 @@
field->arg2,
field->arg3);
if (!ret)
- return 0;
+ return TRACE_TYPE_PARTIAL_LINE;
break;
}
case TRACE_PRINT: {
@@ -1557,7 +1557,7 @@
break;
}
}
- return 1;
+ return TRACE_TYPE_HANDLED;
}
#define SEQ_PUT_FIELD_RET(s, x) \
@@ -1572,7 +1572,7 @@
return 0; \
} while (0)
-static int print_hex_fmt(struct trace_iterator *iter)
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
unsigned char newline = '\n';
@@ -1582,7 +1582,7 @@
entry = iter->ent;
if (entry->type == TRACE_CONT)
- return 1;
+ return TRACE_TYPE_HANDLED;
SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
@@ -1628,10 +1628,10 @@
}
SEQ_PUT_FIELD_RET(s, newline);
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_bin_fmt(struct trace_iterator *iter)
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
@@ -1639,7 +1639,7 @@
entry = iter->ent;
if (entry->type == TRACE_CONT)
- return 1;
+ return TRACE_TYPE_HANDLED;
SEQ_PUT_FIELD_RET(s, entry->pid);
SEQ_PUT_FIELD_RET(s, iter->cpu);
@@ -1686,13 +1686,18 @@
if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
return 0;
}
- return 1;
+ return TRACE_TYPE_HANDLED;
}
-static int print_trace_line(struct trace_iterator *iter)
+static enum print_line_t print_trace_line(struct trace_iterator *iter)
{
- if (iter->trace && iter->trace->print_line)
- return iter->trace->print_line(iter);
+ enum print_line_t ret;
+
+ if (iter->trace && iter->trace->print_line) {
+ ret = iter->trace->print_line(iter);
+ if (ret != TRACE_TYPE_UNHANDLED)
+ return ret;
+ }
if (trace_flags & TRACE_ITER_BIN)
return print_bin_fmt(iter);
@@ -2525,11 +2530,11 @@
ring_buffer_lock(iter->tr->buffer, &flags);
while (find_next_entry_inc(iter) != NULL) {
- int ret;
+ enum print_line_t ret;
int len = iter->seq.len;
ret = print_trace_line(iter);
- if (!ret) {
+ if (ret == TRACE_TYPE_PARTIAL_LINE) {
/* don't print partial lines */
iter->seq.len = len;
break;