linux/arch/x86/oprofile/op_counter.h
Jason Yeh 4d4036e0e7 oprofile: Implement performance counter multiplexing
The number of hardware counters is limited. The multiplexing feature
enables OProfile to gather more events than counters are provided by
the hardware. This is realized by switching between events at an user
specified time interval.

A new file (/dev/oprofile/time_slice) is added for the user to specify
the timer interval in ms. If the number of events to profile is higher
than the number of hardware counters available, the patch will
schedule a work queue that switches the event counter and re-writes
the different sets of values into it. The switching mechanism needs to
be implemented for each architecture to support multiplexing. This
patch only implements AMD CPU support, but multiplexing can be easily
extended for other models and architectures.

There are follow-on patches that rework parts of this patch.

Signed-off-by: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-07-20 16:33:53 +02:00

30 lines
510 B
C

/**
* @file op_counter.h
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon
*/
#ifndef OP_COUNTER_H
#define OP_COUNTER_H
#define OP_MAX_COUNTER 32
/* Per-perfctr configuration as set via
* oprofilefs.
*/
struct op_counter_config {
unsigned long count;
unsigned long enabled;
unsigned long event;
unsigned long kernel;
unsigned long user;
unsigned long unit_mask;
};
extern struct op_counter_config counter_config[];
#endif /* OP_COUNTER_H */