mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 04:30:52 +07:00
6e7458a6f0
In some cases we don't want hard lockup detection enabled by default.
An example is when running as a guest. Introduce
watchdog_enable_hardlockup_detector(bool)
allowing those cases to disable hard lockup detection. This must be
executed early by the boot processor from e.g. smp_prepare_boot_cpu, in
order to allow kernel command line arguments to override it, as well as
to avoid hard lockup detection being enabled before we've had a chance
to indicate that it's unwanted. In summary,
initial boot: default=enabled
smp_prepare_boot_cpu
watchdog_enable_hardlockup_detector(false): default=disabled
cmdline has 'nmi_watchdog=1': default=enabled
The running kernel still has the ability to enable/disable at any time
with /proc/sys/kernel/nmi_watchdog us usual. However even when the
default has been overridden /proc/sys/kernel/nmi_watchdog will initially
show '1'. To truly turn it on one must disable/enable it, i.e.
echo 0 > /proc/sys/kernel/nmi_watchdog
echo 1 > /proc/sys/kernel/nmi_watchdog
This patch will be immediately useful for KVM with the next patch of this
series. Other hypervisor guest types may find it useful as well.
[akpm@linux-foundation.org: fix build]
[dzickus@redhat.com: fix compile issues on sparc]
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
1.9 KiB
C
84 lines
1.9 KiB
C
/*
|
|
* linux/include/linux/nmi.h
|
|
*/
|
|
#ifndef LINUX_NMI_H
|
|
#define LINUX_NMI_H
|
|
|
|
#include <linux/sched.h>
|
|
#include <asm/irq.h>
|
|
|
|
/**
|
|
* touch_nmi_watchdog - restart NMI watchdog timeout.
|
|
*
|
|
* If the architecture supports the NMI watchdog, touch_nmi_watchdog()
|
|
* may be used to reset the timeout - for code which intentionally
|
|
* disables interrupts for a long time. This call is stateless.
|
|
*/
|
|
#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
|
|
#include <asm/nmi.h>
|
|
extern void touch_nmi_watchdog(void);
|
|
#else
|
|
static inline void touch_nmi_watchdog(void)
|
|
{
|
|
touch_softlockup_watchdog();
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_HARDLOCKUP_DETECTOR)
|
|
extern void watchdog_enable_hardlockup_detector(bool val);
|
|
extern bool watchdog_hardlockup_detector_is_enabled(void);
|
|
#else
|
|
static inline void watchdog_enable_hardlockup_detector(bool val)
|
|
{
|
|
}
|
|
static inline bool watchdog_hardlockup_detector_is_enabled(void)
|
|
{
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Create trigger_all_cpu_backtrace() out of the arch-provided
|
|
* base function. Return whether such support was available,
|
|
* to allow calling code to fall back to some other mechanism:
|
|
*/
|
|
#ifdef arch_trigger_all_cpu_backtrace
|
|
static inline bool trigger_all_cpu_backtrace(void)
|
|
{
|
|
arch_trigger_all_cpu_backtrace(true);
|
|
|
|
return true;
|
|
}
|
|
static inline bool trigger_allbutself_cpu_backtrace(void)
|
|
{
|
|
arch_trigger_all_cpu_backtrace(false);
|
|
return true;
|
|
}
|
|
#else
|
|
static inline bool trigger_all_cpu_backtrace(void)
|
|
{
|
|
return false;
|
|
}
|
|
static inline bool trigger_allbutself_cpu_backtrace(void)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_LOCKUP_DETECTOR
|
|
int hw_nmi_is_cpu_stuck(struct pt_regs *);
|
|
u64 hw_nmi_get_sample_period(int watchdog_thresh);
|
|
extern int watchdog_user_enabled;
|
|
extern int watchdog_thresh;
|
|
extern int sysctl_softlockup_all_cpu_backtrace;
|
|
struct ctl_table;
|
|
extern int proc_dowatchdog(struct ctl_table *, int ,
|
|
void __user *, size_t *, loff_t *);
|
|
#endif
|
|
|
|
#ifdef CONFIG_HAVE_ACPI_APEI_NMI
|
|
#include <asm/nmi.h>
|
|
#endif
|
|
|
|
#endif
|