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yaml
---
r: 123483
b: refs/heads/master
c: fbc9bf9
h: refs/heads/master
i:
  123481: 236ab91
  123479: 95a71cd
v: v3
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Robert Richter committed Dec 10, 2008
1 parent 901fc4c commit 1ac8be0
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Showing 4 changed files with 15 additions and 28 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: bf589e32960181fa8cbca7bfdd92265e49dc2dfa
refs/heads/master: fbc9bf9f0ed4f0fbc47dcb5b1c26c28c93b60e33
1 change: 1 addition & 0 deletions trunk/drivers/oprofile/buffer_sync.c
Original file line number Diff line number Diff line change
Expand Up @@ -548,6 +548,7 @@ void sync_buffer(int cpu)

/* Remember, only we can modify tail_pos */

cpu_buffer_reset(cpu);
#ifndef CONFIG_OPROFILE_IBS
available = cpu_buffer_entries(cpu_buf);

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12 changes: 0 additions & 12 deletions trunk/drivers/oprofile/cpu_buffer.c
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Expand Up @@ -124,18 +124,6 @@ void end_cpu_work(void)
flush_scheduled_work();
}

/* Resets the cpu buffer to a sane state. */
void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf)
{
/*
* reset these to invalid values; the next sample collected
* will populate the buffer with proper values to initialize
* the buffer
*/
cpu_buf->last_is_kernel = -1;
cpu_buf->last_task = NULL;
}

/* compute number of available slots in cpu_buffer queue */
static unsigned long nr_available_slots(struct oprofile_cpu_buffer const *b)
{
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28 changes: 13 additions & 15 deletions trunk/drivers/oprofile/cpu_buffer.h
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,19 @@ struct oprofile_cpu_buffer {

DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);

void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf);
/*
* Resets the cpu buffer to a sane state.
*
* reset these to invalid values; the next sample collected will
* populate the buffer with proper values to initialize the buffer
*/
static inline void cpu_buffer_reset(int cpu)
{
struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);

cpu_buf->last_is_kernel = -1;
cpu_buf->last_task = NULL;
}

static inline
struct op_sample *cpu_buffer_write_entry(struct oprofile_cpu_buffer *cpu_buf)
Expand Down Expand Up @@ -88,20 +100,6 @@ unsigned long cpu_buffer_entries(struct oprofile_cpu_buffer *b)
unsigned long head = b->head_pos;
unsigned long tail = b->tail_pos;

/*
* Subtle. This resets the persistent last_task
* and in_kernel values used for switching notes.
* BUT, there is a small window between reading
* head_pos, and this call, that means samples
* can appear at the new head position, but not
* be prefixed with the notes for switching
* kernel mode or a task switch. This small hole
* can lead to mis-attribution or samples where
* we don't know if it's in the kernel or not,
* at the start of an event buffer.
*/
cpu_buffer_reset(b);

if (head >= tail)
return head - tail;

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