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MFi386: rev 1.3:

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- Add debug.watchdog tunable, so we can specify watchdog CPU from loader
  which will help to debug hangs on boot.
- Remove 'U' from debug.watchdog sysctl definition, so if we set it to '-1'
  it really shows '-1'.
- Fix comment.
This commit is contained in:
David E. O'Brien 2005-02-27 22:31:35 +00:00
parent 9c512d4ae0
commit 94a31c6325
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=142722
1 changed files with 31 additions and 20 deletions
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51
sys/amd64/amd64/mp_watchdog.c
View File

@ -49,11 +49,11 @@
#include <machine/mp_watchdog.h>
/*
* mp_swatchdog hijacks the idle thread on a specified CPU, prevents new work
* mp_watchdog hijacks the idle thread on a specified CPU, prevents new work
* from being scheduled there, and uses it as a "watchdog" to detect kernel
* failure on other CPUs. This is made reasonable by inclusion of logical
* processors in Xeon hardware. The watchdog is configured by setting the
* debug.watchdog_cpu sysctl to the CPU of interest. A callout will then
* debug.watchdog sysctl/tunable to the CPU of interest. A callout will then
* begin executing reseting a timer that is gradually lowered by the watching
* thread. If the timer reaches 0, the watchdog fires by ether dropping
* directly to the debugger, or by sending an NMI IPI to the boot processor.
@ -68,11 +68,14 @@ static int watchdog_dontfire = 1;
static int watchdog_timer = -1;
static int watchdog_nmi = 1;
TUNABLE_INT("debug.watchdog", &watchdog_cpu);
SYSCTL_INT(_debug, OID_AUTO, watchdog_nmi, CTLFLAG_RW, &watchdog_nmi, 0,
"IPI the boot processor with an NMI to enter the debugger");
static struct callout watchdog_callout;
static void watchdog_change(int wdcpu);
/*
* Number of seconds before the watchdog will fire if the callout fails to
* reset the timer.
@ -84,6 +87,8 @@ watchdog_init(void *arg)
{
callout_init(&watchdog_callout, CALLOUT_MPSAFE);
if (watchdog_cpu != -1)
watchdog_change(watchdog_cpu);
}
/*
@ -108,6 +113,27 @@ watchdog_function(void *arg)
}
SYSINIT(watchdog_init, SI_SUB_DRIVERS, SI_ORDER_ANY, watchdog_init, NULL);
static void
watchdog_change(int wdcpu)
{
if (wdcpu == -1 || wdcpu == 0xffffffff) {
/*
* Disable the watcdog.
*/
watchdog_cpu = -1;
watchdog_dontfire = 1;
callout_stop(&watchdog_callout);
printf("watchdog stopped\n");
} else {
watchdog_timer = WATCHDOG_THRESHOLD;
watchdog_dontfire = 0;
watchdog_cpu = wdcpu;
callout_reset(&watchdog_callout, 1 * hz, watchdog_function,
NULL);
}
}
/*
* This sysctl sets which CPU is the watchdog CPU. Set to -1 or 0xffffffff
* to disable the watchdog.
@ -122,27 +148,12 @@ sysctl_watchdog(SYSCTL_HANDLER_ARGS)
if (error)
return (error);
if (req->newptr != NULL) {
if (temp == -1 || temp == 0xffffffff) {
/*
* Disable the watcdog.
*/
watchdog_cpu = -1;
watchdog_dontfire = 1;
callout_stop(&watchdog_callout);
printf("watchdog stopped\n");
} else {
watchdog_timer = WATCHDOG_THRESHOLD;
watchdog_dontfire = 0;
watchdog_cpu = temp;
callout_reset(&watchdog_callout, 1 * hz,
watchdog_function, NULL);
}
}
if (req->newptr != NULL)
watchdog_change(temp);
return (0);
}
SYSCTL_PROC(_debug, OID_AUTO, watchdog, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
sysctl_watchdog, "IU", "");
sysctl_watchdog, "I", "");
/*
* A badly behaved sysctl that leaks the sched lock when written to. Then