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-rw-r--r--kernel/trace/Kconfig8
-rw-r--r--kernel/trace/Makefile2
-rw-r--r--kernel/trace/trace.c45
-rw-r--r--kernel/trace/trace.h20
-rw-r--r--kernel/trace/trace_mmiotrace.c295
-rw-r--r--kernel/trace/trace_selftest.c23
-rw-r--r--kernel/trace/trace_sysprof.c363
7 files changed, 756 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 5c2295b29f2..263e9e6bbd6 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -75,6 +75,14 @@ config PREEMPT_TRACER
enabled. This option and the irqs-off timing option can be
used together or separately.)
+config SYSPROF_TRACER
+ bool "Sysprof Tracer"
+ depends on X86
+ select TRACING
+ help
+ This tracer provides the trace needed by the 'Sysprof' userspace
+ tool.
+
config SCHED_TRACER
bool "Scheduling Latency Tracer"
depends on HAVE_FTRACE
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index d9efbbfa2bd..71d17de1728 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -14,9 +14,11 @@ obj-$(CONFIG_FTRACE) += libftrace.o
obj-$(CONFIG_TRACING) += trace.o
obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
+obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o
obj-$(CONFIG_FTRACE) += trace_functions.o
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
libftrace-y := ftrace.o
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2e37857f7df..868e121c8e3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -852,6 +852,48 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
trace_function(tr, data, ip, parent_ip, flags);
}
+#ifdef CONFIG_MMIOTRACE
+void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
+ struct mmiotrace_rw *rw)
+{
+ 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);
+ tracing_generic_entry_update(entry, 0);
+ entry->type = TRACE_MMIO_RW;
+ entry->mmiorw = *rw;
+
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+
+ trace_wake_up();
+}
+
+void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
+ struct mmiotrace_map *map)
+{
+ 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);
+ tracing_generic_entry_update(entry, 0);
+ entry->type = TRACE_MMIO_MAP;
+ entry->mmiomap = *map;
+
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+
+ trace_wake_up();
+}
+#endif
+
void __trace_stack(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long flags,
@@ -2887,6 +2929,9 @@ static __init void tracer_init_debugfs(void)
pr_warning("Could not create debugfs "
"'dyn_ftrace_total_info' entry\n");
#endif
+#ifdef CONFIG_SYSPROF_TRACER
+ init_tracer_sysprof_debugfs(d_tracer);
+#endif
}
static int trace_alloc_page(void)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index df840f42be3..f69f86788c2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -5,6 +5,7 @@
#include <asm/atomic.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
+#include <linux/mmiotrace.h>
enum trace_type {
__TRACE_FIRST_TYPE = 0,
@@ -14,6 +15,8 @@ enum trace_type {
TRACE_WAKE,
TRACE_STACK,
TRACE_SPECIAL,
+ TRACE_MMIO_RW,
+ TRACE_MMIO_MAP,
__TRACE_LAST_TYPE
};
@@ -75,6 +78,8 @@ struct trace_entry {
struct ctx_switch_entry ctx;
struct special_entry special;
struct stack_entry stack;
+ struct mmiotrace_rw mmiorw;
+ struct mmiotrace_map mmiomap;
};
};
@@ -188,6 +193,8 @@ struct trace_iterator {
void tracing_reset(struct trace_array_cpu *data);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
+void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
+
void ftrace(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long ip,
@@ -261,6 +268,15 @@ extern unsigned long ftrace_update_tot_cnt;
extern int DYN_FTRACE_TEST_NAME(void);
#endif
+#ifdef CONFIG_MMIOTRACE
+extern void __trace_mmiotrace_rw(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct mmiotrace_rw *rw);
+extern void __trace_mmiotrace_map(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct mmiotrace_map *map);
+#endif
+
#ifdef CONFIG_FTRACE_STARTUP_TEST
#ifdef CONFIG_FTRACE
extern int trace_selftest_startup_function(struct tracer *trace,
@@ -286,6 +302,10 @@ extern int trace_selftest_startup_wakeup(struct tracer *trace,
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
struct trace_array *tr);
#endif
+#ifdef CONFIG_SYSPROF_TRACER
+extern int trace_selftest_startup_sysprof(struct tracer *trace,
+ struct trace_array *tr);
+#endif
#endif /* CONFIG_FTRACE_STARTUP_TEST */
extern void *head_page(struct trace_array_cpu *data);
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
new file mode 100644
index 00000000000..b13dc19dcbb
--- /dev/null
+++ b/kernel/trace/trace_mmiotrace.c
@@ -0,0 +1,295 @@
+/*
+ * Memory mapped I/O tracing
+ *
+ * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
+ */
+
+#define DEBUG 1
+
+#include <linux/kernel.h>
+#include <linux/mmiotrace.h>
+#include <linux/pci.h>
+
+#include "trace.h"
+
+struct header_iter {
+ struct pci_dev *dev;
+};
+
+static struct trace_array *mmio_trace_array;
+static bool overrun_detected;
+
+static void mmio_reset_data(struct trace_array *tr)
+{
+ int cpu;
+
+ overrun_detected = false;
+ tr->time_start = ftrace_now(tr->cpu);
+
+ for_each_online_cpu(cpu)
+ tracing_reset(tr->data[cpu]);
+}
+
+static void mmio_trace_init(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ mmio_trace_array = tr;
+ if (tr->ctrl) {
+ mmio_reset_data(tr);
+ enable_mmiotrace();
+ }
+}
+
+static void mmio_trace_reset(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ if (tr->ctrl)
+ disable_mmiotrace();
+ mmio_reset_data(tr);
+ mmio_trace_array = NULL;
+}
+
+static void mmio_trace_ctrl_update(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ if (tr->ctrl) {
+ mmio_reset_data(tr);
+ enable_mmiotrace();
+ } else {
+ disable_mmiotrace();
+ }
+}
+
+static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
+{
+ int ret = 0;
+ int i;
+ resource_size_t start, end;
+ const struct pci_driver *drv = pci_dev_driver(dev);
+
+ /* XXX: incomplete checks for trace_seq_printf() return value */
+ ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
+ dev->bus->number, dev->devfn,
+ dev->vendor, dev->device, dev->irq);
+ /*
+ * XXX: is pci_resource_to_user() appropriate, since we are
+ * supposed to interpret the __ioremap() phys_addr argument based on
+ * these printed values?
+ */
+ for (i = 0; i < 7; i++) {
+ pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+ ret += trace_seq_printf(s, " %llx",
+ (unsigned long long)(start |
+ (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
+ }
+ for (i = 0; i < 7; i++) {
+ pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+ ret += trace_seq_printf(s, " %llx",
+ dev->resource[i].start < dev->resource[i].end ?
+ (unsigned long long)(end - start) + 1 : 0);
+ }
+ if (drv)
+ ret += trace_seq_printf(s, " %s\n", drv->name);
+ else
+ ret += trace_seq_printf(s, " \n");
+ return ret;
+}
+
+static void destroy_header_iter(struct header_iter *hiter)
+{
+ if (!hiter)
+ return;
+ pci_dev_put(hiter->dev);
+ kfree(hiter);
+}
+
+static void mmio_pipe_open(struct trace_iterator *iter)
+{
+ struct header_iter *hiter;
+ struct trace_seq *s = &iter->seq;
+
+ trace_seq_printf(s, "VERSION 20070824\n");
+
+ hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
+ if (!hiter)
+ return;
+
+ hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
+ iter->private = hiter;
+}
+
+/* XXX: This is not called when the pipe is closed! */
+static void mmio_close(struct trace_iterator *iter)
+{
+ struct header_iter *hiter = iter->private;
+ destroy_header_iter(hiter);
+ iter->private = NULL;
+}
+
+static unsigned long count_overruns(struct trace_iterator *iter)
+{
+ int cpu;
+ unsigned long cnt = 0;
+ for_each_online_cpu(cpu) {
+ cnt += iter->overrun[cpu];
+ iter->overrun[cpu] = 0;
+ }
+ return cnt;
+}
+
+static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
+ char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ ssize_t ret;
+ struct header_iter *hiter = iter->private;
+ struct trace_seq *s = &iter->seq;
+ unsigned long n;
+
+ n = count_overruns(iter);
+ if (n) {
+ /* XXX: This is later than where events were lost. */
+ trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
+ if (!overrun_detected)
+ pr_warning("mmiotrace has lost events.\n");
+ overrun_detected = true;
+ goto print_out;
+ }
+
+ if (!hiter)
+ return 0;
+
+ mmio_print_pcidev(s, hiter->dev);
+ hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
+
+ if (!hiter->dev) {
+ destroy_header_iter(hiter);
+ iter->private = NULL;
+ }
+
+print_out:
+ ret = trace_seq_to_user(s, ubuf, cnt);
+ return (ret == -EBUSY) ? 0 : ret;
+}
+
+static int mmio_print_rw(struct trace_iterator *iter)
+{
+ struct trace_entry *entry = iter->ent;
+ struct mmiotrace_rw *rw = &entry->mmiorw;
+ struct trace_seq *s = &iter->seq;
+ unsigned long long t = ns2usecs(entry->t);
+ unsigned long usec_rem = do_div(t, 1000000ULL);
+ unsigned secs = (unsigned long)t;
+ int ret = 1;
+
+ switch (entry->mmiorw.opcode) {
+ case MMIO_READ:
+ ret = trace_seq_printf(s,
+ "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
+ rw->width, secs, usec_rem, rw->map_id,
+ (unsigned long long)rw->phys,
+ rw->value, rw->pc, 0);
+ break;
+ case MMIO_WRITE:
+ ret = trace_seq_printf(s,
+ "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
+ rw->width, secs, usec_rem, rw->map_id,
+ (unsigned long long)rw->phys,
+ rw->value, rw->pc, 0);
+ break;
+ case MMIO_UNKNOWN_OP:
+ ret = trace_seq_printf(s,
+ "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n",
+ secs, usec_rem, rw->map_id,
+ (unsigned long long)rw->phys,
+ (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
+ (rw->value >> 0) & 0xff, rw->pc, 0);
+ break;
+ default:
+ ret = trace_seq_printf(s, "rw what?\n");
+ break;
+ }
+ if (ret)
+ return 1;
+ return 0;
+}
+
+static int mmio_print_map(struct trace_iterator *iter)
+{
+ struct trace_entry *entry = iter->ent;
+ struct mmiotrace_map *m = &entry->mmiomap;
+ struct trace_seq *s = &iter->seq;
+ unsigned long long t = ns2usecs(entry->t);
+ unsigned long usec_rem = do_div(t, 1000000ULL);
+ unsigned secs = (unsigned long)t;
+ int ret = 1;
+
+ switch (entry->mmiorw.opcode) {
+ case MMIO_PROBE:
+ ret = trace_seq_printf(s,
+ "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
+ secs, usec_rem, m->map_id,
+ (unsigned long long)m->phys, m->virt, m->len,
+ 0UL, 0);
+ break;
+ case MMIO_UNPROBE:
+ ret = trace_seq_printf(s,
+ "UNMAP %lu.%06lu %d 0x%lx %d\n",
+ secs, usec_rem, m->map_id, 0UL, 0);
+ break;
+ default:
+ ret = trace_seq_printf(s, "map what?\n");
+ break;
+ }
+ if (ret)
+ return 1;
+ return 0;
+}
+
+/* return 0 to abort printing without consuming current entry in pipe mode */
+static int mmio_print_line(struct trace_iterator *iter)
+{
+ switch (iter->ent->type) {
+ case TRACE_MMIO_RW:
+ return mmio_print_rw(iter);
+ case TRACE_MMIO_MAP:
+ return mmio_print_map(iter);
+ default:
+ return 1; /* ignore unknown entries */
+ }
+}
+
+static struct tracer mmio_tracer __read_mostly =
+{
+ .name = "mmiotrace",
+ .init = mmio_trace_init,
+ .reset = mmio_trace_reset,
+ .pipe_open = mmio_pipe_open,
+ .close = mmio_close,
+ .read = mmio_read,
+ .ctrl_update = mmio_trace_ctrl_update,
+ .print_line = mmio_print_line,
+};
+
+__init static int init_mmio_trace(void)
+{
+ return register_tracer(&mmio_tracer);
+}
+device_initcall(init_mmio_trace);
+
+void mmio_trace_rw(struct mmiotrace_rw *rw)
+{
+ struct trace_array *tr = mmio_trace_array;
+ struct trace_array_cpu *data = tr->data[smp_processor_id()];
+ __trace_mmiotrace_rw(tr, data, rw);
+}
+
+void mmio_trace_mapping(struct mmiotrace_map *map)
+{
+ struct trace_array *tr = mmio_trace_array;
+ struct trace_array_cpu *data;
+
+ preempt_disable();
+ data = tr->data[smp_processor_id()];
+ __trace_mmiotrace_map(tr, data, map);
+ preempt_enable();
+}
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 18c5423bc97..0911b7e073b 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -538,3 +538,26 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
return ret;
}
#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
+
+#ifdef CONFIG_SYSPROF_TRACER
+int
+trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
+{
+ unsigned long count;
+ int ret;
+
+ /* start the tracing */
+ tr->ctrl = 1;
+ trace->init(tr);
+ /* Sleep for a 1/10 of a second */
+ msleep(100);
+ /* stop the tracing. */
+ tr->ctrl = 0;
+ trace->ctrl_update(tr);
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+ trace->reset(tr);
+
+ return ret;
+}
+#endif /* CONFIG_SYSPROF_TRACER */
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
new file mode 100644
index 00000000000..2301e1e7c60
--- /dev/null
+++ b/kernel/trace/trace_sysprof.c
@@ -0,0 +1,363 @@
+/*
+ * trace stack traces
+ *
+ * Copyright (C) 2004-2008, Soeren Sandmann
+ * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
+ */
+#include <linux/kallsyms.h>
+#include <linux/debugfs.h>
+#include <linux/hrtimer.h>
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/fs.h>
+
+#include <asm/stacktrace.h>
+
+#include "trace.h"
+
+static struct trace_array *sysprof_trace;
+static int __read_mostly tracer_enabled;
+
+/*
+ * 1 msec sample interval by default:
+ */
+static unsigned long sample_period = 1000000;
+static const unsigned int sample_max_depth = 512;
+
+static DEFINE_MUTEX(sample_timer_lock);
+/*
+ * Per CPU hrtimers that do the profiling:
+ */
+static DEFINE_PER_CPU(struct hrtimer, stack_trace_hrtimer);
+
+struct stack_frame {
+ const void __user *next_fp;
+ unsigned long return_address;
+};
+
+static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
+{
+ int ret;
+
+ if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
+ return 0;
+
+ ret = 1;
+ pagefault_disable();
+ if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+ ret = 0;
+ pagefault_enable();
+
+ return ret;
+}
+
+struct backtrace_info {
+ struct trace_array_cpu *data;
+ struct trace_array *tr;
+ int pos;
+};
+
+static void
+backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+ /* Ignore warnings */
+}
+
+static void backtrace_warning(void *data, char *msg)
+{
+ /* Ignore warnings */
+}
+
+static int backtrace_stack(void *data, char *name)
+{
+ /* Don't bother with IRQ stacks for now */
+ return -1;
+}
+
+static void backtrace_address(void *data, unsigned long addr, int reliable)
+{
+ struct backtrace_info *info = data;
+
+ if (info->pos < sample_max_depth && reliable) {
+ __trace_special(info->tr, info->data, 1, addr, 0);
+
+ info->pos++;
+ }
+}
+
+const static struct stacktrace_ops backtrace_ops = {
+ .warning = backtrace_warning,
+ .warning_symbol = backtrace_warning_symbol,
+ .stack = backtrace_stack,
+ .address = backtrace_address,
+};
+
+static int
+trace_kernel(struct pt_regs *regs, struct trace_array *tr,
+ struct trace_array_cpu *data)
+{
+ struct backtrace_info info;
+ unsigned long bp;
+ char *stack;
+
+ info.tr = tr;
+ info.data = data;
+ info.pos = 1;
+
+ __trace_special(info.tr, info.data, 1, regs->ip, 0);
+
+ stack = ((char *)regs + sizeof(struct pt_regs));
+#ifdef CONFIG_FRAME_POINTER
+ bp = regs->bp;
+#else
+ bp = 0;
+#endif
+
+ dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, &info);
+
+ return info.pos;
+}
+
+static void timer_notify(struct pt_regs *regs, int cpu)
+{
+ struct trace_array_cpu *data;
+ struct stack_frame frame;
+ struct trace_array *tr;
+ const void __user *fp;
+ int is_user;
+ int i;
+
+ if (!regs)
+ return;
+
+ tr = sysprof_trace;
+ data = tr->data[cpu];
+ is_user = user_mode(regs);
+
+ if (!current || current->pid == 0)
+ return;
+
+ if (is_user && current->state != TASK_RUNNING)
+ return;
+
+ __trace_special(tr, data, 0, 0, current->pid);
+
+ if (!is_user)
+ i = trace_kernel(regs, tr, data);
+ else
+ i = 0;
+
+ /*
+ * Trace user stack if we are not a kernel thread
+ */
+ if (current->mm && i < sample_max_depth) {
+ regs = (struct pt_regs *)current->thread.sp0 - 1;
+
+ fp = (void __user *)regs->bp;
+
+ __trace_special(tr, data, 2, regs->ip, 0);
+
+ while (i < sample_max_depth) {
+ frame.next_fp = 0;
+ frame.return_address = 0;
+ if (!copy_stack_frame(fp, &frame))
+ break;
+ if ((unsigned long)fp < regs->sp)
+ break;
+
+ __trace_special(tr, data, 2, frame.return_address,
+ (unsigned long)fp);
+ fp = frame.next_fp;
+
+ i++;
+ }
+
+ }
+
+ /*
+ * Special trace entry if we overflow the max depth:
+ */
+ if (i == sample_max_depth)
+ __trace_special(tr, data, -1, -1, -1);
+
+ __trace_special(tr, data, 3, current->pid, i);
+}
+
+static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer)
+{
+ /* trace here */
+ timer_notify(get_irq_regs(), smp_processor_id());
+
+ hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period));
+
+ return HRTIMER_RESTART;
+}
+
+static void start_stack_timer(int cpu)
+{
+ struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);
+
+ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer->function = stack_trace_timer_fn;
+ hrtimer->cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+
+ hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL);
+}
+
+static void start_stack_timers(void)
+{
+ cpumask_t saved_mask = current->cpus_allowed;
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ start_stack_timer(cpu);
+ }
+ set_cpus_allowed_ptr(current, &saved_mask);
+}
+
+static void stop_stack_timer(int cpu)
+{
+ struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);
+
+ hrtimer_cancel(hrtimer);
+}
+
+static void stop_stack_timers(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ stop_stack_timer(cpu);
+}
+
+static void stack_reset(struct trace_array *tr)
+{
+ int cpu;
+
+ tr->time_start = ftrace_now(tr->cpu);
+
+ for_each_online_cpu(cpu)
+ tracing_reset(tr->data[cpu]);
+}
+
+static void start_stack_trace(struct trace_array *tr)
+{
+ mutex_lock(&sample_timer_lock);
+ stack_reset(tr);
+ start_stack_timers();
+ tracer_enabled = 1;
+ mutex_unlock(&sample_timer_lock);
+}
+
+static void stop_stack_trace(struct trace_array *tr)
+{
+ mutex_lock(&sample_timer_lock);
+ stop_stack_timers();
+ tracer_enabled = 0;
+ mutex_unlock(&sample_timer_lock);
+}
+
+static void stack_trace_init(struct trace_array *tr)
+{
+ sysprof_trace = tr;
+
+ if (tr->ctrl)
+ start_stack_trace(tr);
+}
+
+static void stack_trace_reset(struct trace_array *tr)
+{
+ if (tr->ctrl)
+ stop_stack_trace(tr);
+}
+
+static void stack_trace_ctrl_update(struct trace_array *tr)
+{
+ /* When starting a new trace, reset the buffers */
+ if (tr->ctrl)
+ start_stack_trace(tr);
+ else
+ stop_stack_trace(tr);
+}
+
+static struct tracer stack_trace __read_mostly =
+{
+ .name = "sysprof",
+ .init = stack_trace_init,
+ .reset = stack_trace_reset,
+ .ctrl_update = stack_trace_ctrl_update,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_sysprof,
+#endif
+};
+
+__init static int init_stack_trace(void)
+{
+ return register_tracer(&stack_trace);
+}
+device_initcall(init_stack_trace);
+
+#define MAX_LONG_DIGITS 22
+
+static ssize_t
+sysprof_sample_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[MAX_LONG_DIGITS];
+ int r;
+
+ r = sprintf(buf, "%ld\n", nsecs_to_usecs(sample_period));
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+sysprof_sample_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[MAX_LONG_DIGITS];
+ unsigned long val;
+
+ if (cnt > MAX_LONG_DIGITS-1)
+ cnt = MAX_LONG_DIGITS-1;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ val = simple_strtoul(buf, NULL, 10);
+ /*
+ * Enforce a minimum sample period of 100 usecs:
+ */
+ if (val < 100)
+ val = 100;
+
+ mutex_lock(&sample_timer_lock);
+ stop_stack_timers();
+ sample_period = val * 1000;
+ start_stack_timers();
+ mutex_unlock(&sample_timer_lock);
+
+ return cnt;
+}
+
+static struct file_operations sysprof_sample_fops = {
+ .read = sysprof_sample_read,
+ .write = sysprof_sample_write,
+};
+
+void init_tracer_sysprof_debugfs(struct dentry *d_tracer)
+{
+ struct dentry *entry;
+
+ entry = debugfs_create_file("sysprof_sample_period", 0644,
+ d_tracer, NULL, &sysprof_sample_fops);
+ if (entry)
+ return;
+ pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n");
+}