ftrace: make work with new ring buffer
This patch ports ftrace over to the new ring buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6ada059..ef80793 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -33,25 +33,22 @@
#include <linux/writeback.h>
#include <linux/stacktrace.h>
+#include <linux/ring_buffer.h>
#include "trace.h"
+#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
+
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly tracing_thresh;
-static unsigned long __read_mostly tracing_nr_buffers;
static cpumask_t __read_mostly tracing_buffer_mask;
#define for_each_tracing_cpu(cpu) \
for_each_cpu_mask(cpu, tracing_buffer_mask)
-static int trace_alloc_page(void);
-static int trace_free_page(void);
-
static int tracing_disabled = 1;
-static unsigned long tracing_pages_allocated;
-
long
ns2usecs(cycle_t nsec)
{
@@ -62,7 +59,9 @@
cycle_t ftrace_now(int cpu)
{
- return cpu_clock(cpu);
+ u64 ts = ring_buffer_time_stamp(cpu);
+ ring_buffer_normalize_time_stamp(cpu, &ts);
+ return ts;
}
/*
@@ -102,18 +101,18 @@
int ftrace_function_enabled;
/*
- * trace_nr_entries is the number of entries that is allocated
- * for a buffer. Note, the number of entries is always rounded
- * to ENTRIES_PER_PAGE.
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
*
* This number is purposely set to a low number of 16384.
* If the dump on oops happens, it will be much appreciated
* to not have to wait for all that output. Anyway this can be
* boot time and run time configurable.
*/
-#define TRACE_ENTRIES_DEFAULT 16384UL
+#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
-static unsigned long trace_nr_entries = TRACE_ENTRIES_DEFAULT;
+static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
/* trace_types holds a link list of available tracers. */
static struct tracer *trace_types __read_mostly;
@@ -158,23 +157,21 @@
wake_up(&trace_wait);
}
-#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
-
-static int __init set_nr_entries(char *str)
+static int __init set_buf_size(char *str)
{
- unsigned long nr_entries;
+ unsigned long buf_size;
int ret;
if (!str)
return 0;
- ret = strict_strtoul(str, 0, &nr_entries);
+ ret = strict_strtoul(str, 0, &buf_size);
/* nr_entries can not be zero */
- if (ret < 0 || nr_entries == 0)
+ if (ret < 0 || buf_size == 0)
return 0;
- trace_nr_entries = nr_entries;
+ trace_buf_size = buf_size;
return 1;
}
-__setup("trace_entries=", set_nr_entries);
+__setup("trace_buf_size=", set_buf_size);
unsigned long nsecs_to_usecs(unsigned long nsecs)
{
@@ -243,54 +240,6 @@
tracing_record_cmdline(current);
}
-#define CHECK_COND(cond) \
- if (unlikely(cond)) { \
- tracing_disabled = 1; \
- WARN_ON(1); \
- return -1; \
- }
-
-/**
- * check_pages - integrity check of trace buffers
- *
- * As a safty measure we check to make sure the data pages have not
- * been corrupted.
- */
-int check_pages(struct trace_array_cpu *data)
-{
- struct page *page, *tmp;
-
- CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
- CHECK_COND(data->trace_pages.prev->next != &data->trace_pages);
-
- list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
- CHECK_COND(page->lru.next->prev != &page->lru);
- CHECK_COND(page->lru.prev->next != &page->lru);
- }
-
- return 0;
-}
-
-/**
- * head_page - page address of the first page in per_cpu buffer.
- *
- * head_page returns the page address of the first page in
- * a per_cpu buffer. This also preforms various consistency
- * checks to make sure the buffer has not been corrupted.
- */
-void *head_page(struct trace_array_cpu *data)
-{
- struct page *page;
-
- if (list_empty(&data->trace_pages))
- return NULL;
-
- page = list_entry(data->trace_pages.next, struct page, lru);
- BUG_ON(&page->lru == &data->trace_pages);
-
- return page_address(page);
-}
-
/**
* trace_seq_printf - sequence printing of trace information
* @s: trace sequence descriptor
@@ -437,34 +386,6 @@
trace_seq_reset(s);
}
-/*
- * flip the trace buffers between two trace descriptors.
- * This usually is the buffers between the global_trace and
- * the max_tr to record a snapshot of a current trace.
- *
- * The ftrace_max_lock must be held.
- */
-static void
-flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
-{
- struct list_head flip_pages;
-
- INIT_LIST_HEAD(&flip_pages);
-
- memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
- sizeof(struct trace_array_cpu) -
- offsetof(struct trace_array_cpu, trace_head_idx));
-
- check_pages(tr1);
- check_pages(tr2);
- list_splice_init(&tr1->trace_pages, &flip_pages);
- list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
- list_splice_init(&flip_pages, &tr2->trace_pages);
- BUG_ON(!list_empty(&flip_pages));
- check_pages(tr1);
- check_pages(tr2);
-}
-
/**
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
* @tr: tracer
@@ -477,17 +398,15 @@
void
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
- struct trace_array_cpu *data;
- int i;
+ struct ring_buffer *buf = tr->buffer;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
- /* clear out all the previous traces */
- for_each_tracing_cpu(i) {
- data = tr->data[i];
- flip_trace(max_tr.data[i], data);
- tracing_reset(data);
- }
+
+ tr->buffer = max_tr.buffer;
+ max_tr.buffer = buf;
+
+ ring_buffer_reset(tr->buffer);
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
@@ -504,16 +423,15 @@
void
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
- struct trace_array_cpu *data = tr->data[cpu];
- int i;
+ int ret;
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
- for_each_tracing_cpu(i)
- tracing_reset(max_tr.data[i]);
- flip_trace(max_tr.data[cpu], data);
- tracing_reset(data);
+ ring_buffer_reset(max_tr.buffer);
+ ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+
+ WARN_ON_ONCE(ret);
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
@@ -550,7 +468,6 @@
#ifdef CONFIG_FTRACE_STARTUP_TEST
if (type->selftest) {
struct tracer *saved_tracer = current_trace;
- struct trace_array_cpu *data;
struct trace_array *tr = &global_trace;
int saved_ctrl = tr->ctrl;
int i;
@@ -562,10 +479,7 @@
* If we fail, we do not register this tracer.
*/
for_each_tracing_cpu(i) {
- data = tr->data[i];
- if (!head_page(data))
- continue;
- tracing_reset(data);
+ tracing_reset(tr, i);
}
current_trace = type;
tr->ctrl = 0;
@@ -581,10 +495,7 @@
}
/* Only reset on passing, to avoid touching corrupted buffers */
for_each_tracing_cpu(i) {
- data = tr->data[i];
- if (!head_page(data))
- continue;
- tracing_reset(data);
+ tracing_reset(tr, i);
}
printk(KERN_CONT "PASSED\n");
}
@@ -630,13 +541,9 @@
mutex_unlock(&trace_types_lock);
}
-void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array *tr, int cpu)
{
- data->trace_idx = 0;
- data->overrun = 0;
- data->trace_head = data->trace_tail = head_page(data);
- data->trace_head_idx = 0;
- data->trace_tail_idx = 0;
+ ring_buffer_reset_cpu(tr->buffer, cpu);
}
#define SAVED_CMDLINES 128
@@ -722,70 +629,6 @@
trace_save_cmdline(tsk);
}
-static inline struct list_head *
-trace_next_list(struct trace_array_cpu *data, struct list_head *next)
-{
- /*
- * Roundrobin - but skip the head (which is not a real page):
- */
- next = next->next;
- if (unlikely(next == &data->trace_pages))
- next = next->next;
- BUG_ON(next == &data->trace_pages);
-
- return next;
-}
-
-static inline void *
-trace_next_page(struct trace_array_cpu *data, void *addr)
-{
- struct list_head *next;
- struct page *page;
-
- page = virt_to_page(addr);
-
- next = trace_next_list(data, &page->lru);
- page = list_entry(next, struct page, lru);
-
- return page_address(page);
-}
-
-struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
-{
- unsigned long idx, idx_next;
- struct trace_entry *entry;
-
- data->trace_idx++;
- idx = data->trace_head_idx;
- idx_next = idx + 1;
-
- BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
-
- entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
-
- if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
- data->trace_head = trace_next_page(data, data->trace_head);
- idx_next = 0;
- }
-
- if (data->trace_head == data->trace_tail &&
- idx_next == data->trace_tail_idx) {
- /* overrun */
- data->overrun++;
- data->trace_tail_idx++;
- if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
- data->trace_tail =
- trace_next_page(data, data->trace_tail);
- data->trace_tail_idx = 0;
- }
- }
-
- data->trace_head_idx = idx_next;
-
- return entry;
-}
-
void
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
{
@@ -796,7 +639,6 @@
entry->field.preempt_count = pc & 0xff;
entry->field.pid = (tsk) ? tsk->pid : 0;
- entry->field.t = ftrace_now(raw_smp_processor_id());
entry->field.flags =
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
@@ -808,18 +650,20 @@
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
unsigned long ip, unsigned long parent_ip, unsigned long flags)
{
+ struct ring_buffer_event *event;
struct trace_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_FN;
entry->field.fn.ip = ip;
entry->field.fn.parent_ip = parent_ip;
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
void
@@ -835,13 +679,19 @@
unsigned long flags,
int skip)
{
+ struct ring_buffer_event *event;
struct trace_entry *entry;
struct stack_trace trace;
+ unsigned long irq_flags;
if (!(trace_flags & TRACE_ITER_STACKTRACE))
return;
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_STACK;
@@ -853,28 +703,31 @@
trace.entries = entry->field.stack.caller;
save_stack_trace(&trace);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
void
__trace_special(void *__tr, void *__data,
unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
+ struct ring_buffer_event *event;
struct trace_array_cpu *data = __data;
struct trace_array *tr = __tr;
struct trace_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, 0);
entry->type = TRACE_SPECIAL;
entry->field.special.arg1 = arg1;
entry->field.special.arg2 = arg2;
entry->field.special.arg3 = arg3;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
__trace_stack(tr, data, irq_flags, 4);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
trace_wake_up();
}
@@ -886,12 +739,15 @@
struct task_struct *next,
unsigned long flags)
{
+ struct ring_buffer_event *event;
struct trace_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_CTX;
entry->field.ctx.prev_pid = prev->pid;
@@ -901,9 +757,8 @@
entry->field.ctx.next_prio = next->prio;
entry->field.ctx.next_state = next->state;
entry->field.ctx.next_cpu = task_cpu(next);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
__trace_stack(tr, data, flags, 5);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
}
void
@@ -913,12 +768,15 @@
struct task_struct *curr,
unsigned long flags)
{
+ struct ring_buffer_event *event;
struct trace_entry *entry;
unsigned long irq_flags;
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_WAKE;
entry->field.ctx.prev_pid = curr->pid;
@@ -928,9 +786,8 @@
entry->field.ctx.next_prio = wakee->prio;
entry->field.ctx.next_state = wakee->state;
entry->field.ctx.next_cpu = task_cpu(wakee);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
__trace_stack(tr, data, flags, 6);
- __raw_spin_unlock(&data->lock);
- raw_local_irq_restore(irq_flags);
trace_wake_up();
}
@@ -1011,183 +868,77 @@
TRACE_FILE_LAT_FMT = 1,
};
-/* Return the current entry. */
-static struct trace_entry *
-trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
- struct trace_iterator *iter, int cpu)
-{
- struct page *page;
- struct trace_entry *array;
-
- if (iter->next_idx[cpu] >= tr->entries ||
- iter->next_idx[cpu] >= data->trace_idx ||
- (data->trace_head == data->trace_tail &&
- data->trace_head_idx == data->trace_tail_idx))
- return NULL;
-
- if (!iter->next_page[cpu]) {
- /* Initialize the iterator for this cpu trace buffer */
- WARN_ON(!data->trace_tail);
- page = virt_to_page(data->trace_tail);
- iter->next_page[cpu] = &page->lru;
- iter->next_page_idx[cpu] = data->trace_tail_idx;
- }
-
- page = list_entry(iter->next_page[cpu], struct page, lru);
- BUG_ON(&data->trace_pages == &page->lru);
-
- array = page_address(page);
-
- WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
- return &array[iter->next_page_idx[cpu]];
-}
-
-/* Increment the index counter of an iterator by one */
-static void __trace_iterator_increment(struct trace_iterator *iter, int cpu)
-{
- iter->next_idx[cpu]++;
- iter->next_page_idx[cpu]++;
-
- if (iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE) {
- struct trace_array_cpu *data = iter->tr->data[cpu];
-
- iter->next_page_idx[cpu] = 0;
- iter->next_page[cpu] =
- trace_next_list(data, iter->next_page[cpu]);
- }
-}
-
static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
{
iter->idx++;
- __trace_iterator_increment(iter, cpu);
+ ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
}
static struct trace_entry *
-trace_entry_next(struct trace_array *tr, struct trace_array_cpu *data,
- struct trace_iterator *iter, int cpu)
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
{
- struct list_head *next_page;
- struct trace_entry *ent;
- int idx, next_idx, next_page_idx;
+ struct ring_buffer_event *event;
+ struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
- ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
-
- if (likely(!ent || ent->type != TRACE_CONT))
- return ent;
-
- /* save the iterator details */
- idx = iter->idx;
- next_idx = iter->next_idx[cpu];
- next_page_idx = iter->next_page_idx[cpu];
- next_page = iter->next_page[cpu];
-
- /* find a real entry */
- do {
- __trace_iterator_increment(iter, cpu);
- ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
- } while (ent && ent->type != TRACE_CONT);
-
- /* reset the iterator */
- iter->idx = idx;
- iter->next_idx[cpu] = next_idx;
- iter->next_page_idx[cpu] = next_page_idx;
- iter->next_page[cpu] = next_page;
-
- return ent;
+ event = ring_buffer_iter_peek(buf_iter, ts);
+ return event ? ring_buffer_event_data(event) : NULL;
}
-
static struct trace_entry *
-__find_next_entry(struct trace_iterator *iter, int *ent_cpu, int inc)
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
{
- struct trace_array *tr = iter->tr;
+ struct ring_buffer *buffer = iter->tr->buffer;
struct trace_entry *ent, *next = NULL;
+ u64 next_ts = 0, ts;
int next_cpu = -1;
int cpu;
for_each_tracing_cpu(cpu) {
- if (!head_page(tr->data[cpu]))
+
+ if (ring_buffer_empty_cpu(buffer, cpu))
continue;
- ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
-
- if (ent && ent->type == TRACE_CONT) {
- struct trace_array_cpu *data = tr->data[cpu];
-
- if (!inc)
- ent = trace_entry_next(tr, data, iter, cpu);
- else {
- while (ent && ent->type == TRACE_CONT) {
- __trace_iterator_increment(iter, cpu);
- ent = trace_entry_idx(tr, tr->data[cpu],
- iter, cpu);
- }
- }
- }
+ ent = peek_next_entry(iter, cpu, &ts);
/*
* Pick the entry with the smallest timestamp:
*/
- if (ent && (!next || ent->field.t < next->field.t)) {
+ if (ent && (!next || ts < next_ts)) {
next = ent;
next_cpu = cpu;
+ next_ts = ts;
}
}
if (ent_cpu)
*ent_cpu = next_cpu;
+ if (ent_ts)
+ *ent_ts = next_ts;
+
return next;
}
/* Find the next real entry, without updating the iterator itself */
static struct trace_entry *
-find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
{
- return __find_next_entry(iter, ent_cpu, 0);
+ return __find_next_entry(iter, ent_cpu, ent_ts);
}
/* Find the next real entry, and increment the iterator to the next entry */
static void *find_next_entry_inc(struct trace_iterator *iter)
{
- struct trace_entry *next;
- int next_cpu = -1;
+ iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
- next = __find_next_entry(iter, &next_cpu, 1);
-
- iter->prev_ent = iter->ent;
- iter->prev_cpu = iter->cpu;
-
- iter->ent = next;
- iter->cpu = next_cpu;
-
- if (next)
+ if (iter->ent)
trace_iterator_increment(iter, iter->cpu);
- return next ? iter : NULL;
+ return iter->ent ? iter : NULL;
}
static void trace_consume(struct trace_iterator *iter)
{
- struct trace_array_cpu *data = iter->tr->data[iter->cpu];
- struct trace_entry *ent;
-
- again:
- data->trace_tail_idx++;
- if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
- data->trace_tail = trace_next_page(data, data->trace_tail);
- data->trace_tail_idx = 0;
- }
-
- /* Check if we empty it, then reset the index */
- if (data->trace_head == data->trace_tail &&
- data->trace_head_idx == data->trace_tail_idx)
- data->trace_idx = 0;
-
- ent = trace_entry_idx(iter->tr, iter->tr->data[iter->cpu],
- iter, iter->cpu);
- if (ent && ent->type == TRACE_CONT)
- goto again;
+ ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
}
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
@@ -1220,7 +971,7 @@
struct trace_iterator *iter = m->private;
void *p = NULL;
loff_t l = 0;
- int i;
+ int cpu;
mutex_lock(&trace_types_lock);
@@ -1239,12 +990,9 @@
iter->ent = NULL;
iter->cpu = 0;
iter->idx = -1;
- iter->prev_ent = NULL;
- iter->prev_cpu = -1;
- for_each_tracing_cpu(i) {
- iter->next_idx[i] = 0;
- iter->next_page[i] = NULL;
+ for_each_tracing_cpu(cpu) {
+ ring_buffer_iter_reset(iter->buffer_iter[cpu]);
}
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
@@ -1365,23 +1113,16 @@
struct trace_array *tr = iter->tr;
struct trace_array_cpu *data = tr->data[tr->cpu];
struct tracer *type = current_trace;
- unsigned long total = 0;
- unsigned long entries = 0;
- int cpu;
+ unsigned long total;
+ unsigned long entries;
const char *name = "preemption";
if (type)
name = type->name;
- for_each_tracing_cpu(cpu) {
- if (head_page(tr->data[cpu])) {
- total += tr->data[cpu]->trace_idx;
- if (tr->data[cpu]->trace_idx > tr->entries)
- entries += tr->entries;
- else
- entries += tr->data[cpu]->trace_idx;
- }
- }
+ entries = ring_buffer_entries(iter->tr->buffer);
+ total = entries +
+ ring_buffer_overruns(iter->tr->buffer);
seq_printf(m, "%s latency trace v1.1.5 on %s\n",
name, UTS_RELEASE);
@@ -1468,7 +1209,7 @@
unsigned long preempt_mark_thresh = 100;
static void
-lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
unsigned long rel_usecs)
{
trace_seq_printf(s, " %4lldus", abs_usecs);
@@ -1488,12 +1229,10 @@
*/
void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
{
- struct trace_array *tr = iter->tr;
- struct trace_array_cpu *data = tr->data[iter->cpu];
struct trace_entry *ent;
bool ok = true;
- ent = trace_entry_idx(tr, data, iter, iter->cpu);
+ ent = peek_next_entry(iter, iter->cpu, NULL);
if (!ent || ent->type != TRACE_CONT) {
trace_seq_putc(s, '\n');
return;
@@ -1502,8 +1241,8 @@
do {
if (ok)
ok = (trace_seq_printf(s, "%s", ent->cont.buf) > 0);
- __trace_iterator_increment(iter, iter->cpu);
- ent = trace_entry_idx(tr, data, iter, iter->cpu);
+ ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+ ent = peek_next_entry(iter, iter->cpu, NULL);
} while (ent && ent->type == TRACE_CONT);
if (!ok)
@@ -1515,25 +1254,26 @@
{
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);
+ struct trace_entry *next_entry;
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
struct trace_entry *entry = iter->ent;
struct trace_field *field = &entry->field;
unsigned long abs_usecs;
unsigned long rel_usecs;
+ u64 next_ts;
char *comm;
int S, T;
int i;
unsigned state;
- if (!next_entry)
- next_entry = entry;
-
if (entry->type == TRACE_CONT)
return 1;
- rel_usecs = ns2usecs(next_entry->field.t - entry->field.t);
- abs_usecs = ns2usecs(entry->field.t - iter->tr->time_start);
+ next_entry = find_next_entry(iter, NULL, &next_ts);
+ if (!next_entry)
+ next_ts = iter->ts;
+ rel_usecs = ns2usecs(next_ts - iter->ts);
+ abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
if (verbose) {
comm = trace_find_cmdline(field->pid);
@@ -1542,7 +1282,7 @@
comm,
field->pid, cpu, field->flags,
field->preempt_count, trace_idx,
- ns2usecs(field->t),
+ ns2usecs(iter->ts),
abs_usecs/1000,
abs_usecs % 1000, rel_usecs/1000,
rel_usecs % 1000);
@@ -1627,7 +1367,7 @@
comm = trace_find_cmdline(iter->ent->field.pid);
- t = ns2usecs(field->t);
+ t = ns2usecs(iter->ts);
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
@@ -1732,7 +1472,7 @@
field = &entry->field;
ret = trace_seq_printf(s, "%d %d %llu ",
- field->pid, iter->cpu, field->t);
+ field->pid, iter->cpu, iter->ts);
if (!ret)
return 0;
@@ -1811,7 +1551,7 @@
SEQ_PUT_HEX_FIELD_RET(s, field->pid);
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
- SEQ_PUT_HEX_FIELD_RET(s, field->t);
+ SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
switch (entry->type) {
case TRACE_FN:
@@ -1861,7 +1601,7 @@
SEQ_PUT_FIELD_RET(s, field->pid);
SEQ_PUT_FIELD_RET(s, field->cpu);
- SEQ_PUT_FIELD_RET(s, field->t);
+ SEQ_PUT_FIELD_RET(s, iter->ts);
switch (entry->type) {
case TRACE_FN:
@@ -1888,15 +1628,10 @@
static int trace_empty(struct trace_iterator *iter)
{
- struct trace_array_cpu *data;
int cpu;
for_each_tracing_cpu(cpu) {
- data = iter->tr->data[cpu];
-
- if (head_page(data) && data->trace_idx &&
- (data->trace_tail != data->trace_head ||
- data->trace_tail_idx != data->trace_head_idx))
+ if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
return 0;
}
return 1;
@@ -1961,6 +1696,8 @@
__tracing_open(struct inode *inode, struct file *file, int *ret)
{
struct trace_iterator *iter;
+ struct seq_file *m;
+ int cpu;
if (tracing_disabled) {
*ret = -ENODEV;
@@ -1981,28 +1718,43 @@
iter->trace = current_trace;
iter->pos = -1;
+ for_each_tracing_cpu(cpu) {
+ iter->buffer_iter[cpu] =
+ ring_buffer_read_start(iter->tr->buffer, cpu);
+ if (!iter->buffer_iter[cpu])
+ goto fail_buffer;
+ }
+
/* TODO stop tracer */
*ret = seq_open(file, &tracer_seq_ops);
- if (!*ret) {
- struct seq_file *m = file->private_data;
- m->private = iter;
+ if (*ret)
+ goto fail_buffer;
- /* stop the trace while dumping */
- if (iter->tr->ctrl) {
- tracer_enabled = 0;
- ftrace_function_enabled = 0;
- }
+ m = file->private_data;
+ m->private = iter;
- if (iter->trace && iter->trace->open)
- iter->trace->open(iter);
- } else {
- kfree(iter);
- iter = NULL;
+ /* stop the trace while dumping */
+ if (iter->tr->ctrl) {
+ tracer_enabled = 0;
+ ftrace_function_enabled = 0;
}
+
+ if (iter->trace && iter->trace->open)
+ iter->trace->open(iter);
+
mutex_unlock(&trace_types_lock);
out:
return iter;
+
+ fail_buffer:
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ return ERR_PTR(-ENOMEM);
}
int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -2018,8 +1770,14 @@
{
struct seq_file *m = (struct seq_file *)file->private_data;
struct trace_iterator *iter = m->private;
+ int cpu;
mutex_lock(&trace_types_lock);
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+
if (iter->trace && iter->trace->close)
iter->trace->close(iter);
@@ -2526,6 +2284,7 @@
static int tracing_open_pipe(struct inode *inode, struct file *filp)
{
struct trace_iterator *iter;
+ int cpu;
if (tracing_disabled)
return -ENODEV;
@@ -2546,17 +2305,38 @@
iter->trace = current_trace;
filp->private_data = iter;
+ for_each_tracing_cpu(cpu) {
+ iter->buffer_iter[cpu] =
+ ring_buffer_read_start(iter->tr->buffer, cpu);
+ if (!iter->buffer_iter[cpu])
+ goto fail_buffer;
+ }
+
if (iter->trace->pipe_open)
iter->trace->pipe_open(iter);
mutex_unlock(&trace_types_lock);
return 0;
+
+ fail_buffer:
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ return -ENOMEM;
}
static int tracing_release_pipe(struct inode *inode, struct file *file)
{
struct trace_iterator *iter = file->private_data;
+ int cpu;
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
kfree(iter);
atomic_dec(&tracing_reader);
@@ -2592,13 +2372,10 @@
size_t cnt, loff_t *ppos)
{
struct trace_iterator *iter = filp->private_data;
- struct trace_array_cpu *data;
- static cpumask_t mask;
unsigned long flags;
#ifdef CONFIG_FTRACE
int ftrace_save;
#endif
- int cpu;
ssize_t sret;
/* return any leftover data */
@@ -2687,32 +2464,13 @@
* and then release the locks again.
*/
- cpus_clear(mask);
- local_irq_save(flags);
+ local_irq_disable();
#ifdef CONFIG_FTRACE
ftrace_save = ftrace_enabled;
ftrace_enabled = 0;
#endif
smp_wmb();
- for_each_tracing_cpu(cpu) {
- data = iter->tr->data[cpu];
-
- if (!head_page(data) || !data->trace_idx)
- continue;
-
- atomic_inc(&data->disabled);
- cpu_set(cpu, mask);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- __raw_spin_lock(&data->lock);
-
- if (data->overrun > iter->last_overrun[cpu])
- iter->overrun[cpu] +=
- data->overrun - iter->last_overrun[cpu];
- iter->last_overrun[cpu] = data->overrun;
- }
+ ring_buffer_lock(iter->tr->buffer, &flags);
while (find_next_entry_inc(iter) != NULL) {
int ret;
@@ -2731,19 +2489,11 @@
break;
}
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- __raw_spin_unlock(&data->lock);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter->tr->data[cpu];
- atomic_dec(&data->disabled);
- }
+ ring_buffer_unlock(iter->tr->buffer, flags);
#ifdef CONFIG_FTRACE
ftrace_enabled = ftrace_save;
#endif
- local_irq_restore(flags);
+ local_irq_enable();
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
@@ -2776,7 +2526,7 @@
{
unsigned long val;
char buf[64];
- int i, ret;
+ int ret;
struct trace_array *tr = filp->private_data;
if (cnt >= sizeof(buf))
@@ -2804,52 +2554,31 @@
goto out;
}
- if (val > global_trace.entries) {
- long pages_requested;
- unsigned long freeable_pages;
-
- /* make sure we have enough memory before mapping */
- pages_requested =
- (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
-
- /* account for each buffer (and max_tr) */
- pages_requested *= tracing_nr_buffers * 2;
-
- /* Check for overflow */
- if (pages_requested < 0) {
- cnt = -ENOMEM;
+ if (val != global_trace.entries) {
+ ret = ring_buffer_resize(global_trace.buffer, val);
+ if (ret < 0) {
+ cnt = ret;
goto out;
}
- freeable_pages = determine_dirtyable_memory();
-
- /* we only allow to request 1/4 of useable memory */
- if (pages_requested >
- ((freeable_pages + tracing_pages_allocated) / 4)) {
- cnt = -ENOMEM;
- goto out;
- }
-
- while (global_trace.entries < val) {
- if (trace_alloc_page()) {
- cnt = -ENOMEM;
- goto out;
+ ret = ring_buffer_resize(max_tr.buffer, val);
+ if (ret < 0) {
+ int r;
+ cnt = ret;
+ r = ring_buffer_resize(global_trace.buffer,
+ global_trace.entries);
+ if (r < 0) {
+ /* AARGH! We are left with different
+ * size max buffer!!!! */
+ WARN_ON(1);
+ tracing_disabled = 1;
}
- /* double check that we don't go over the known pages */
- if (tracing_pages_allocated > pages_requested)
- break;
+ goto out;
}
- } else {
- /* include the number of entries in val (inc of page entries) */
- while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
- trace_free_page();
+ global_trace.entries = val;
}
- /* check integrity */
- for_each_tracing_cpu(i)
- check_pages(global_trace.data[i]);
-
filp->f_pos += cnt;
/* If check pages failed, return ENOMEM */
@@ -3086,10 +2815,11 @@
static DEFINE_SPINLOCK(trace_buf_lock);
static char trace_buf[TRACE_BUF_SIZE];
+ struct ring_buffer_event *event;
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
struct trace_entry *entry;
- unsigned long flags;
+ unsigned long flags, irq_flags;
long disabled;
int cpu, len = 0, write, written = 0;
@@ -3110,8 +2840,11 @@
len = min(len, TRACE_BUF_SIZE-1);
trace_buf[len] = 0;
- __raw_spin_lock(&data->lock);
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ goto out_unlock;
+ entry = ring_buffer_event_data(event);
tracing_generic_entry_update(entry, flags);
entry->type = TRACE_PRINT;
entry->field.print.ip = ip;
@@ -3121,21 +2854,27 @@
memcpy(&entry->field.print.buf, trace_buf, write);
entry->field.print.buf[write] = 0;
written = write;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
if (written != len)
entry->field.flags |= TRACE_FLAG_CONT;
while (written != len) {
- entry = tracing_get_trace_entry(tr, data);
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ goto out_unlock;
+ entry = ring_buffer_event_data(event);
entry->type = TRACE_CONT;
write = min(len - written, (int)(TRACE_CONT_BUF_SIZE-1));
memcpy(&entry->cont.buf, trace_buf+written, write);
entry->cont.buf[write] = 0;
written += write;
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
- __raw_spin_unlock(&data->lock);
+ out_unlock:
spin_unlock(&trace_buf_lock);
out:
@@ -3227,12 +2966,10 @@
static DEFINE_SPINLOCK(ftrace_dump_lock);
/* use static because iter can be a bit big for the stack */
static struct trace_iterator iter;
- struct trace_array_cpu *data;
static cpumask_t mask;
static int dump_ran;
- unsigned long flags;
+ unsigned long flags, irq_flags;
int cnt = 0;
- int cpu;
/* only one dump */
spin_lock_irqsave(&ftrace_dump_lock, flags);
@@ -3258,25 +2995,7 @@
cpus_clear(mask);
- for_each_tracing_cpu(cpu) {
- data = iter.tr->data[cpu];
-
- if (!head_page(data) || !data->trace_idx)
- continue;
-
- atomic_inc(&data->disabled);
- cpu_set(cpu, mask);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter.tr->data[cpu];
- __raw_spin_lock(&data->lock);
-
- if (data->overrun > iter.last_overrun[cpu])
- iter.overrun[cpu] +=
- data->overrun - iter.last_overrun[cpu];
- iter.last_overrun[cpu] = data->overrun;
- }
+ ring_buffer_lock(iter.tr->buffer, &irq_flags);
while (!trace_empty(&iter)) {
@@ -3305,206 +3024,48 @@
else
printk(KERN_TRACE "---------------------------------\n");
- for_each_cpu_mask(cpu, mask) {
- data = iter.tr->data[cpu];
- __raw_spin_unlock(&data->lock);
- }
-
- for_each_cpu_mask(cpu, mask) {
- data = iter.tr->data[cpu];
- atomic_dec(&data->disabled);
- }
-
+ ring_buffer_unlock(iter.tr->buffer, irq_flags);
out:
spin_unlock_irqrestore(&ftrace_dump_lock, flags);
}
-static int trace_alloc_page(void)
-{
- struct trace_array_cpu *data;
- struct page *page, *tmp;
- LIST_HEAD(pages);
- void *array;
- unsigned pages_allocated = 0;
- int i;
-
- /* first allocate a page for each CPU */
- for_each_tracing_cpu(i) {
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_pages;
- }
-
- pages_allocated++;
- page = virt_to_page(array);
- list_add(&page->lru, &pages);
-
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_pages;
- }
- pages_allocated++;
- page = virt_to_page(array);
- list_add(&page->lru, &pages);
-#endif
- }
-
- /* Now that we successfully allocate a page per CPU, add them */
- for_each_tracing_cpu(i) {
- data = global_trace.data[i];
- page = list_entry(pages.next, struct page, lru);
- list_del_init(&page->lru);
- list_add_tail(&page->lru, &data->trace_pages);
- ClearPageLRU(page);
-
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- page = list_entry(pages.next, struct page, lru);
- list_del_init(&page->lru);
- list_add_tail(&page->lru, &data->trace_pages);
- SetPageLRU(page);
-#endif
- }
- tracing_pages_allocated += pages_allocated;
- global_trace.entries += ENTRIES_PER_PAGE;
-
- return 0;
-
- free_pages:
- list_for_each_entry_safe(page, tmp, &pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- return -ENOMEM;
-}
-
-static int trace_free_page(void)
-{
- struct trace_array_cpu *data;
- struct page *page;
- struct list_head *p;
- int i;
- int ret = 0;
-
- /* free one page from each buffer */
- for_each_tracing_cpu(i) {
- data = global_trace.data[i];
- p = data->trace_pages.next;
- if (p == &data->trace_pages) {
- /* should never happen */
- WARN_ON(1);
- tracing_disabled = 1;
- ret = -1;
- break;
- }
- page = list_entry(p, struct page, lru);
- ClearPageLRU(page);
- list_del(&page->lru);
- tracing_pages_allocated--;
- tracing_pages_allocated--;
- __free_page(page);
-
- tracing_reset(data);
-
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- p = data->trace_pages.next;
- if (p == &data->trace_pages) {
- /* should never happen */
- WARN_ON(1);
- tracing_disabled = 1;
- ret = -1;
- break;
- }
- page = list_entry(p, struct page, lru);
- ClearPageLRU(page);
- list_del(&page->lru);
- __free_page(page);
-
- tracing_reset(data);
-#endif
- }
- global_trace.entries -= ENTRIES_PER_PAGE;
-
- return ret;
-}
-
__init static int tracer_alloc_buffers(void)
{
struct trace_array_cpu *data;
- void *array;
- struct page *page;
- int pages = 0;
- int ret = -ENOMEM;
int i;
/* TODO: make the number of buffers hot pluggable with CPUS */
- tracing_nr_buffers = num_possible_cpus();
tracing_buffer_mask = cpu_possible_map;
+ global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+ TRACE_BUFFER_FLAGS);
+ if (!global_trace.buffer) {
+ printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
+ WARN_ON(1);
+ return 0;
+ }
+ global_trace.entries = ring_buffer_size(global_trace.buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+ TRACE_BUFFER_FLAGS);
+ if (!max_tr.buffer) {
+ printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
+ WARN_ON(1);
+ ring_buffer_free(global_trace.buffer);
+ return 0;
+ }
+ max_tr.entries = ring_buffer_size(max_tr.buffer);
+ WARN_ON(max_tr.entries != global_trace.entries);
+#endif
+
/* Allocate the first page for all buffers */
for_each_tracing_cpu(i) {
data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
max_tr.data[i] = &per_cpu(max_data, i);
-
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_buffers;
- }
-
- /* set the array to the list */
- INIT_LIST_HEAD(&data->trace_pages);
- page = virt_to_page(array);
- list_add(&page->lru, &data->trace_pages);
- /* use the LRU flag to differentiate the two buffers */
- ClearPageLRU(page);
-
- data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
- array = (void *)__get_free_page(GFP_KERNEL);
- if (array == NULL) {
- printk(KERN_ERR "tracer: failed to allocate page"
- "for trace buffer!\n");
- goto free_buffers;
- }
-
- INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
- page = virt_to_page(array);
- list_add(&page->lru, &max_tr.data[i]->trace_pages);
- SetPageLRU(page);
-#endif
}
- /*
- * Since we allocate by orders of pages, we may be able to
- * round up a bit.
- */
- global_trace.entries = ENTRIES_PER_PAGE;
- pages++;
-
- while (global_trace.entries < trace_nr_entries) {
- if (trace_alloc_page())
- break;
- pages++;
- }
- max_tr.entries = global_trace.entries;
-
- pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
- pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
- pr_info(" actual entries %ld\n", global_trace.entries);
-
trace_init_cmdlines();
register_tracer(&nop_trace);
@@ -3519,38 +3080,13 @@
/* All seems OK, enable tracing */
global_trace.ctrl = tracer_enabled;
tracing_disabled = 0;
+
atomic_notifier_chain_register(&panic_notifier_list,
&trace_panic_notifier);
register_die_notifier(&trace_die_notifier);
return 0;
-
- free_buffers:
- for (i-- ; i >= 0; i--) {
- struct page *page, *tmp;
- struct trace_array_cpu *data = global_trace.data[i];
-
- if (data) {
- list_for_each_entry_safe(page, tmp,
- &data->trace_pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- }
-
-#ifdef CONFIG_TRACER_MAX_TRACE
- data = max_tr.data[i];
- if (data) {
- list_for_each_entry_safe(page, tmp,
- &data->trace_pages, lru) {
- list_del_init(&page->lru);
- __free_page(page);
- }
- }
-#endif
- }
- return ret;
}
early_initcall(tracer_alloc_buffers);
fs_initcall(tracer_init_debugfs);
