ftrace: add a buffer for output
Later patches will need to print the same things as the seq output
does. But those outputs will not use the seq utility. This patch
adds a buffer to the iterator, that can be used by either the
seq utility or other output.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 777b859..d39f4fa 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -169,6 +169,66 @@
return page_address(page);
}
+static notrace int
+trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
+{
+ int len = (PAGE_SIZE - 1) - s->len;
+ va_list ap;
+
+ if (!len)
+ return 0;
+
+ va_start(ap, fmt);
+ len = vsnprintf(s->buffer + s->len, len, fmt, ap);
+ va_end(ap);
+
+ s->len += len;
+
+ return len;
+}
+
+static notrace int
+trace_seq_puts(struct trace_seq *s, const char *str)
+{
+ int len = strlen(str);
+
+ if (len > ((PAGE_SIZE - 1) - s->len))
+ len = (PAGE_SIZE - 1) - s->len;
+
+ memcpy(s->buffer + s->len, str, len);
+ s->len += len;
+
+ return len;
+}
+
+static notrace int
+trace_seq_putc(struct trace_seq *s, unsigned char c)
+{
+ if (s->len >= (PAGE_SIZE - 1))
+ return 0;
+
+ s->buffer[s->len++] = c;
+
+ return 1;
+}
+
+static notrace void
+trace_seq_reset(struct trace_seq *s)
+{
+ s->len = 0;
+}
+
+static notrace void
+trace_print_seq(struct seq_file *m, struct trace_seq *s)
+{
+ int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
+
+ s->buffer[len] = 0;
+ seq_puts(m, s->buffer);
+
+ trace_seq_reset(s);
+}
+
notrace static void
flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
{
@@ -756,25 +816,26 @@
}
static void
-seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address)
+seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
char str[KSYM_SYMBOL_LEN];
kallsyms_lookup(address, NULL, NULL, NULL, str);
- seq_printf(m, fmt, str);
+ trace_seq_printf(s, fmt, str);
#endif
}
static void
-seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address)
+seq_print_sym_offset(struct trace_seq *s, const char *fmt,
+ unsigned long address)
{
#ifdef CONFIG_KALLSYMS
char str[KSYM_SYMBOL_LEN];
sprint_symbol(str, address);
- seq_printf(m, fmt, str);
+ trace_seq_printf(s, fmt, str);
#endif
}
@@ -785,20 +846,20 @@
#endif
static notrace void
-seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
{
if (!ip) {
- seq_printf(m, "0");
+ trace_seq_printf(s, "0");
return;
}
if (sym_flags & TRACE_ITER_SYM_OFFSET)
- seq_print_sym_offset(m, "%s", ip);
+ seq_print_sym_offset(s, "%s", ip);
else
- seq_print_sym_short(m, "%s", ip);
+ seq_print_sym_short(s, "%s", ip);
if (sym_flags & TRACE_ITER_SYM_ADDR)
- seq_printf(m, " <" IP_FMT ">", ip);
+ trace_seq_printf(s, " <" IP_FMT ">", ip);
}
static notrace void print_lat_help_header(struct seq_file *m)
@@ -881,9 +942,11 @@
if (data->critical_start) {
seq_puts(m, " => started at: ");
- seq_print_ip_sym(m, data->critical_start, sym_flags);
+ seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
+ trace_print_seq(m, &iter->seq);
seq_puts(m, "\n => ended at: ");
- seq_print_ip_sym(m, data->critical_end, sym_flags);
+ seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
+ trace_print_seq(m, &iter->seq);
seq_puts(m, "\n");
}
@@ -891,61 +954,61 @@
}
static notrace void
-lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
+lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
{
int hardirq, softirq;
char *comm;
comm = trace_find_cmdline(entry->pid);
- seq_printf(m, "%8.8s-%-5d ", comm, entry->pid);
- seq_printf(m, "%d", cpu);
- seq_printf(m, "%c%c",
- (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
- ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
+ trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
+ trace_seq_printf(s, "%d", cpu);
+ trace_seq_printf(s, "%c%c",
+ (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+ ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
if (hardirq && softirq)
- seq_putc(m, 'H');
+ trace_seq_putc(s, 'H');
else {
if (hardirq)
- seq_putc(m, 'h');
+ trace_seq_putc(s, 'h');
else {
if (softirq)
- seq_putc(m, 's');
+ trace_seq_putc(s, 's');
else
- seq_putc(m, '.');
+ trace_seq_putc(s, '.');
}
}
if (entry->preempt_count)
- seq_printf(m, "%x", entry->preempt_count);
+ trace_seq_printf(s, "%x", entry->preempt_count);
else
- seq_puts(m, ".");
+ trace_seq_puts(s, ".");
}
unsigned long preempt_mark_thresh = 100;
static notrace void
-lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
unsigned long rel_usecs)
{
- seq_printf(m, " %4lldus", abs_usecs);
+ trace_seq_printf(s, " %4lldus", abs_usecs);
if (rel_usecs > preempt_mark_thresh)
- seq_puts(m, "!: ");
+ trace_seq_puts(s, "!: ");
else if (rel_usecs > 1)
- seq_puts(m, "+: ");
+ trace_seq_puts(s, "+: ");
else
- seq_puts(m, " : ");
+ trace_seq_puts(s, " : ");
}
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
static notrace void
-print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
- unsigned int trace_idx, int cpu)
+print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
{
+ struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
struct trace_entry *next_entry = find_next_entry(iter, NULL);
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
@@ -962,39 +1025,40 @@
if (verbose) {
comm = trace_find_cmdline(entry->pid);
- seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]"
- " %ld.%03ldms (+%ld.%03ldms): ",
- comm,
- entry->pid, cpu, entry->flags,
- entry->preempt_count, trace_idx,
- ns2usecs(entry->t),
- abs_usecs/1000,
- abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000);
+ trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+ " %ld.%03ldms (+%ld.%03ldms): ",
+ comm,
+ entry->pid, cpu, entry->flags,
+ entry->preempt_count, trace_idx,
+ ns2usecs(entry->t),
+ abs_usecs/1000,
+ abs_usecs % 1000, rel_usecs/1000,
+ rel_usecs % 1000);
} else {
- lat_print_generic(m, entry, cpu);
- lat_print_timestamp(m, abs_usecs, rel_usecs);
+ lat_print_generic(s, entry, cpu);
+ lat_print_timestamp(s, abs_usecs, rel_usecs);
}
switch (entry->type) {
case TRACE_FN:
- seq_print_ip_sym(m, entry->fn.ip, sym_flags);
- seq_puts(m, " (");
- seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
- seq_puts(m, ")\n");
+ seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ trace_seq_puts(s, " (");
+ seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+ trace_seq_puts(s, ")\n");
break;
case TRACE_CTX:
S = entry->ctx.prev_state < sizeof(state_to_char) ?
state_to_char[entry->ctx.prev_state] : 'X';
comm = trace_find_cmdline(entry->ctx.next_pid);
- seq_printf(m, " %d:%d:%c --> %d:%d %s\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
- S,
- entry->ctx.next_pid,
- entry->ctx.next_prio,
- comm);
+ trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio,
+ comm);
break;
default:
- seq_printf(m, "Unknown type %d\n", entry->type);
+ trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
}
@@ -1026,8 +1090,9 @@
}
static notrace void
-print_trace_fmt(struct seq_file *m, struct trace_iterator *iter)
+print_trace_fmt(struct trace_iterator *iter)
{
+ struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
struct trace_entry *entry;
unsigned long usec_rem;
@@ -1045,29 +1110,29 @@
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
- seq_printf(m, "%16s-%-5d ", comm, entry->pid);
- seq_printf(m, "[%02d] ", iter->cpu);
- seq_printf(m, "%5lu.%06lu: ", secs, usec_rem);
+ trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ trace_seq_printf(s, "[%02d] ", iter->cpu);
+ trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
switch (entry->type) {
case TRACE_FN:
- seq_print_ip_sym(m, entry->fn.ip, sym_flags);
+ seq_print_ip_sym(s, entry->fn.ip, sym_flags);
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
entry->fn.parent_ip) {
- seq_printf(m, " <-");
- seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
+ trace_seq_printf(s, " <-");
+ seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
}
- seq_printf(m, "\n");
+ trace_seq_printf(s, "\n");
break;
case TRACE_CTX:
S = entry->ctx.prev_state < sizeof(state_to_char) ?
state_to_char[entry->ctx.prev_state] : 'X';
- seq_printf(m, " %d:%d:%c ==> %d:%d\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
- S,
- entry->ctx.next_pid,
- entry->ctx.next_prio);
+ trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio);
break;
}
}
@@ -1108,9 +1173,10 @@
}
} else {
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
- print_lat_fmt(m, iter, iter->idx, iter->cpu);
+ print_lat_fmt(iter, iter->idx, iter->cpu);
else
- print_trace_fmt(m, iter);
+ print_trace_fmt(iter);
+ trace_print_seq(m, &iter->seq);
}
return 0;