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![Babu Moger](/assets/img/avatar_default.png)
Patch series "Clean up watchdog handlers", v2. This is an attempt to cleanup watchdog handlers. Right now, kernel/watchdog.c implements both softlockup and hardlockup detectors. Softlockup code is generic. Hardlockup code is arch specific. Some architectures don't use hardlockup detectors. They use their own watchdog detectors. To make both these combination work, we have numerous #ifdefs in kernel/watchdog.c. We are trying here to make these handlers independent of each other. Also provide an interface for architectures to implement their own handlers. watchdog_nmi_enable and watchdog_nmi_disable will be defined as weak such that architectures can override its definitions. Thanks to Don Zickus for his suggestions. Here are our previous discussions http://www.spinics.net/lists/sparclinux/msg16543.html http://www.spinics.net/lists/sparclinux/msg16441.html This patch (of 3): Move shared macros and definitions to nmi.h so that watchdog.c, new file watchdog_hld.c or any other architecture specific handler can use those definitions. Link: http://lkml.kernel.org/r/1478034826-43888-2-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Josh Hunt <johunt@akamai.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
149 lines
4.2 KiB
C
149 lines
4.2 KiB
C
/*
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* linux/include/linux/nmi.h
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*/
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#ifndef LINUX_NMI_H
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#define LINUX_NMI_H
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#include <linux/sched.h>
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#include <asm/irq.h>
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/*
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* The run state of the lockup detectors is controlled by the content of the
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* 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
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* bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
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*
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* 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
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* are variables that are only used as an 'interface' between the parameters
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* in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
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* 'watchdog_thresh' variable is handled differently because its value is not
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* boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
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* is equal zero.
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*/
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#define NMI_WATCHDOG_ENABLED_BIT 0
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#define SOFT_WATCHDOG_ENABLED_BIT 1
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#define NMI_WATCHDOG_ENABLED (1 << NMI_WATCHDOG_ENABLED_BIT)
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#define SOFT_WATCHDOG_ENABLED (1 << SOFT_WATCHDOG_ENABLED_BIT)
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/**
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* touch_nmi_watchdog - restart NMI watchdog timeout.
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*
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* If the architecture supports the NMI watchdog, touch_nmi_watchdog()
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* may be used to reset the timeout - for code which intentionally
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* disables interrupts for a long time. This call is stateless.
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*/
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#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
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#include <asm/nmi.h>
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extern void touch_nmi_watchdog(void);
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#else
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static inline void touch_nmi_watchdog(void)
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{
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touch_softlockup_watchdog();
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}
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#endif
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#if defined(CONFIG_HARDLOCKUP_DETECTOR)
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extern void hardlockup_detector_disable(void);
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#else
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static inline void hardlockup_detector_disable(void) {}
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#endif
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/*
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* Create trigger_all_cpu_backtrace() out of the arch-provided
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* base function. Return whether such support was available,
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* to allow calling code to fall back to some other mechanism:
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*/
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#ifdef arch_trigger_cpumask_backtrace
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static inline bool trigger_all_cpu_backtrace(void)
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{
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arch_trigger_cpumask_backtrace(cpu_online_mask, false);
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return true;
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}
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static inline bool trigger_allbutself_cpu_backtrace(void)
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{
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arch_trigger_cpumask_backtrace(cpu_online_mask, true);
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return true;
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}
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static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
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{
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arch_trigger_cpumask_backtrace(mask, false);
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return true;
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}
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static inline bool trigger_single_cpu_backtrace(int cpu)
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{
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arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
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return true;
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}
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/* generic implementation */
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void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
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bool exclude_self,
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void (*raise)(cpumask_t *mask));
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bool nmi_cpu_backtrace(struct pt_regs *regs);
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#else
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static inline bool trigger_all_cpu_backtrace(void)
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{
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return false;
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}
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static inline bool trigger_allbutself_cpu_backtrace(void)
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{
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return false;
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}
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static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
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{
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return false;
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}
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static inline bool trigger_single_cpu_backtrace(int cpu)
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{
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return false;
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}
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#endif
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#ifdef CONFIG_LOCKUP_DETECTOR
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u64 hw_nmi_get_sample_period(int watchdog_thresh);
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extern int nmi_watchdog_enabled;
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extern int soft_watchdog_enabled;
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extern int watchdog_user_enabled;
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extern int watchdog_thresh;
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extern unsigned long watchdog_enabled;
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extern unsigned long *watchdog_cpumask_bits;
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#ifdef CONFIG_SMP
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extern int sysctl_softlockup_all_cpu_backtrace;
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extern int sysctl_hardlockup_all_cpu_backtrace;
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#else
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#define sysctl_softlockup_all_cpu_backtrace 0
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#define sysctl_hardlockup_all_cpu_backtrace 0
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#endif
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extern bool is_hardlockup(void);
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struct ctl_table;
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extern int proc_watchdog(struct ctl_table *, int ,
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void __user *, size_t *, loff_t *);
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extern int proc_nmi_watchdog(struct ctl_table *, int ,
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void __user *, size_t *, loff_t *);
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extern int proc_soft_watchdog(struct ctl_table *, int ,
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void __user *, size_t *, loff_t *);
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extern int proc_watchdog_thresh(struct ctl_table *, int ,
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void __user *, size_t *, loff_t *);
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extern int proc_watchdog_cpumask(struct ctl_table *, int,
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void __user *, size_t *, loff_t *);
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extern int lockup_detector_suspend(void);
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extern void lockup_detector_resume(void);
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#else
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static inline int lockup_detector_suspend(void)
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{
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return 0;
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}
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static inline void lockup_detector_resume(void)
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{
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}
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#endif
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#ifdef CONFIG_HAVE_ACPI_APEI_NMI
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#include <asm/nmi.h>
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#endif
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#endif
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