Commit 89b2f978 authored by Steven Rostedt's avatar Steven Rostedt Committed by Thomas Gleixner
Browse files

ftrace: fix updates to max trace



This patch fixes some bugs to the updating of the max trace that
was caused by implementing the new buffering.
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 18cef379
......@@ -153,6 +153,7 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
memcpy(max_tr.data[i], data, sizeof(*data));
data->trace = save_trace;
data->trace_pages = save_pages;
tracing_reset(data);
}
__update_max_tr(tr, tsk, cpu);
......@@ -183,6 +184,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
memcpy(max_tr.data[cpu], data, sizeof(*data));
data->trace = save_trace;
data->trace_pages = save_pages;
tracing_reset(data);
__update_max_tr(tr, tsk, cpu);
spin_unlock(&ftrace_max_lock);
......@@ -877,6 +879,8 @@ print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
entry->ctx.next_prio,
comm);
break;
default:
seq_printf(m, "Unknown type %d\n", entry->type);
}
}
......@@ -1625,7 +1629,6 @@ __init static int tracer_alloc_buffers(void)
* round up a bit.
*/
global_trace.entries = ENTRIES_PER_PAGE;
max_tr.entries = global_trace.entries;
pages++;
while (global_trace.entries < trace_nr_entries) {
......@@ -1633,6 +1636,7 @@ __init static int tracer_alloc_buffers(void)
break;
pages++;
}
max_tr.entries = global_trace.entries;
pr_info("tracer: %d pages allocated for %ld",
pages, trace_nr_entries);
......
......@@ -23,6 +23,8 @@ static int tracer_enabled __read_mostly;
static DEFINE_PER_CPU(int, tracing_cpu);
static DEFINE_SPINLOCK(max_trace_lock);
enum {
TRACER_IRQS_OFF = (1 << 1),
TRACER_PREEMPT_OFF = (1 << 2),
......@@ -126,7 +128,7 @@ check_critical_timing(struct trace_array *tr,
int cpu)
{
unsigned long latency, t0, t1;
cycle_t T0, T1, T2, delta;
cycle_t T0, T1, delta;
unsigned long flags;
/*
......@@ -142,20 +144,18 @@ check_critical_timing(struct trace_array *tr,
if (!report_latency(delta))
goto out;
ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
/*
* Update the timestamp, because the trace entry above
* might change it (it can only get larger so the latency
* is fair to be reported):
*/
T2 = now(cpu);
spin_lock(&max_trace_lock);
delta = T2-T0;
/* check if we are still the max latency */
if (!report_latency(delta))
goto out_unlock;
ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
latency = nsecs_to_usecs(delta);
if (data->critical_sequence != max_sequence)
goto out;
goto out_unlock;
tracing_max_latency = delta;
t0 = nsecs_to_usecs(T0);
......@@ -189,6 +189,9 @@ check_critical_timing(struct trace_array *tr,
max_sequence++;
out_unlock:
spin_unlock(&max_trace_lock);
out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = now(cpu);
......@@ -366,14 +369,14 @@ void notrace trace_preempt_off(unsigned long a0, unsigned long a1)
static void start_irqsoff_tracer(struct trace_array *tr)
{
tracer_enabled = 1;
register_ftrace_function(&trace_ops);
tracer_enabled = 1;
}
static void stop_irqsoff_tracer(struct trace_array *tr)
{
unregister_ftrace_function(&trace_ops);
tracer_enabled = 0;
unregister_ftrace_function(&trace_ops);
}
static void __irqsoff_tracer_init(struct trace_array *tr)
......
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