This patch replaces the schedule safe preempt disable code with the
ftrace_preempt_disable and ftrace_preempt_enable safe functions.

Signed-off-by: Steven Rostedt
---
kernel/trace/ring_buffer.c | 27 +++++++++------------------
kernel/trace/trace.c | 8 ++------
kernel/trace/trace_sched_wakeup.c | 13 ++-----------
kernel/trace/trace_stack.c | 8 ++------
4 files changed, 15 insertions(+), 41 deletions(-)

Index: linux-tip.git/kernel/trace/ring_buffer.c
================================================== =================
--- linux-tip.git.orig/kernel/trace/ring_buffer.c 2008-11-03 18:49:30.000000000 -0500
+++ linux-tip.git/kernel/trace/ring_buffer.c 2008-11-03 19:05:24.000000000 -0500
@@ -16,6 +16,8 @@
#include
#include

+#include "trace.h"
+
/* Up this if you want to test the TIME_EXTENTS and normalization */
#define DEBUG_SHIFT 0

@@ -1122,8 +1124,7 @@ ring_buffer_lock_reserve(struct ring_buf
return NULL;

/* If we are tracing schedule, we don't want to recurse */
- resched = need_resched();
- preempt_disable_notrace();
+ resched = ftrace_preempt_disable();

cpu = raw_smp_processor_id();

@@ -1154,10 +1155,7 @@ ring_buffer_lock_reserve(struct ring_buf
return event;

out:
- if (resched)
- preempt_enable_notrace();
- else
- preempt_enable_notrace();
+ ftrace_preempt_enable(resched);
return NULL;
}

@@ -1199,12 +1197,9 @@ int ring_buffer_unlock_commit(struct rin
/*
* Only the last preempt count needs to restore preemption.
*/
- if (preempt_count() == 1) {
- if (per_cpu(rb_need_resched, cpu))
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
- } else
+ if (preempt_count() == 1)
+ ftrace_preempt_enable(per_cpu(rb_need_resched, cpu));
+ else
preempt_enable_no_resched_notrace();

return 0;
@@ -1237,8 +1232,7 @@ int ring_buffer_write(struct ring_buffer
if (atomic_read(&buffer->record_disabled))
return -EBUSY;

- resched = need_resched();
- preempt_disable_notrace();
+ resched = ftrace_preempt_disable();

cpu = raw_smp_processor_id();

@@ -1264,10 +1258,7 @@ int ring_buffer_write(struct ring_buffer

ret = 0;
out:
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
+ ftrace_preempt_enable(resched);

return ret;
}
Index: linux-tip.git/kernel/trace/trace.c
================================================== =================
--- linux-tip.git.orig/kernel/trace/trace.c 2008-11-03 18:49:37.000000000 -0500
+++ linux-tip.git/kernel/trace/trace.c 2008-11-03 19:05:24.000000000 -0500
@@ -893,8 +893,7 @@ function_trace_call(unsigned long ip, un
return;

pc = preempt_count();
- resched = need_resched();
- preempt_disable_notrace();
+ resched = ftrace_preempt_disable();
local_save_flags(flags);
cpu = raw_smp_processor_id();
data = tr->data[cpu];
@@ -904,10 +903,7 @@ function_trace_call(unsigned long ip, un
trace_function(tr, data, ip, parent_ip, flags, pc);

atomic_dec(&data->disabled);
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
+ ftrace_preempt_enable(resched);
}

static struct ftrace_ops trace_ops __read_mostly =
Index: linux-tip.git/kernel/trace/trace_sched_wakeup.c
================================================== =================
--- linux-tip.git.orig/kernel/trace/trace_sched_wakeup.c 2008-11-03 18:49:30.000000000 -0500
+++ linux-tip.git/kernel/trace/trace_sched_wakeup.c 2008-11-03 19:05:24.000000000 -0500
@@ -50,8 +50,7 @@ wakeup_tracer_call(unsigned long ip, uns
return;

pc = preempt_count();
- resched = need_resched();
- preempt_disable_notrace();
+ resched = ftrace_preempt_disable();

cpu = raw_smp_processor_id();
data = tr->data[cpu];
@@ -81,15 +80,7 @@ wakeup_tracer_call(unsigned long ip, uns
out:
atomic_dec(&data->disabled);

- /*
- * To prevent recursion from the scheduler, if the
- * resched flag was set before we entered, then
- * don't reschedule.
- */
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
+ ftrace_preempt_enable(resched);
}

static struct ftrace_ops trace_ops __read_mostly =
Index: linux-tip.git/kernel/trace/trace_stack.c
================================================== =================
--- linux-tip.git.orig/kernel/trace/trace_stack.c 2008-11-03 18:49:30.000000000 -0500
+++ linux-tip.git/kernel/trace/trace_stack.c 2008-11-03 19:05:24.000000000 -0500
@@ -107,8 +107,7 @@ stack_trace_call(unsigned long ip, unsig
if (unlikely(!ftrace_enabled || stack_trace_disabled))
return;

- resched = need_resched();
- preempt_disable_notrace();
+ resched = ftrace_preempt_disable();

cpu = raw_smp_processor_id();
/* no atomic needed, we only modify this variable by this cpu */
@@ -120,10 +119,7 @@ stack_trace_call(unsigned long ip, unsig
out:
per_cpu(trace_active, cpu)--;
/* prevent recursion in schedule */
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
+ ftrace_preempt_enable(resched);
}

static struct ftrace_ops trace_ops __read_mostly =

--
--
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