minix/kernel/watchdog.h
Tomas Hruby e63b85a50b NMI sampling
- if profile --nmi kernel uses NMI watchdog based sampling based on
  Intel architecture performance counters

- using NMI makes kernel profiling possible

- watchdog kernel lockup detection is disabled while sampling as we
  may get unpredictable interrupts in kernel and thus possibly many
  false positives

- if watchdog is not enabled at boot time, profiling enables it and
  turns it of again when done
2010-09-23 10:49:45 +00:00

47 lines
1.6 KiB
C

#ifndef __WATCHDOG_H__
#define __WATCHDOG_H__
#include "kernel.h"
#include "arch_watchdog.h"
extern int watchdog_enabled; /* if set to non-zero the watch dog is enabled */
extern unsigned watchdog_local_timer_ticks; /* is timer still ticking? */
/*
* as the implementation is not only architecture dependent but like in x86 case
* very much model specific, we need to keep a collection of methods that
* implement it in runtime after the correct arch/model was detected
*/
typedef void (* arch_watchdog_method_t)(const unsigned);
typedef int (* arch_watchdog_profile_init_t)(const unsigned);
struct arch_watchdog {
arch_watchdog_method_t init; /* initial setup */
arch_watchdog_method_t reinit; /* reinit after a tick */
arch_watchdog_profile_init_t profile_init;
unsigned resetval;
unsigned watchdog_resetval;
unsigned profile_resetval;
};
extern struct arch_watchdog *watchdog;
/* let the arch code do whatever it needs to setup or quit the watchdog */
int arch_watchdog_init(void);
void arch_watchdog_stop(void);
/* if the watchdog detects lockup, let the arch code to handle it */
void arch_watchdog_lockup(const struct nmi_frame * frame);
/* generic NMI handler. Takes one agument which points to where the arch
* specific low level handler dumped CPU information and can be inspected by the
* arch specific code of the watchdog implementaion */
void nmi_watchdog_handler(struct nmi_frame * frame);
/*
* start and stop profiling using the NMI watchdog
*/
int nmi_watchdog_start_profiling(const unsigned freq);
void nmi_watchdog_stop_profiling(void);
#endif /* __WATCHDOG_H__ */