projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| f6c19f6e MD |
1 | /* |
| 2 | * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com) | |
| 3 | * | |
| 4 | * Contains LTTng trace clock mapping to LTTng trace clock or mainline monotonic | |
| 5 | * clock. This wrapper depends on CONFIG_HIGH_RES_TIMERS=y. | |
| 6 | * | |
| 7 | * Dual LGPL v2.1/GPL v2 license. | |
| 8 | */ | |
| 9 | ||
| 10 | #ifndef _LTT_TRACE_CLOCK_H | |
| 11 | #define _LTT_TRACE_CLOCK_H | |
| 12 | ||
| 13 | #ifdef CONFIG_HAVE_TRACE_CLOCK | |
| 14 | #include <linux/trace-clock.h> | |
| 15 | #else /* CONFIG_HAVE_TRACE_CLOCK */ | |
| 16 | ||
| 17 | #include <linux/hardirq.h> | |
| 18 | #include <linux/ktime.h> | |
| 19 | #include <linux/time.h> | |
| 20 | #include <linux/hrtimer.h> | |
| 21 | ||
| 22 | static inline u64 trace_clock_monotonic_wrapper(void) | |
| 23 | { | |
| 24 | ktime_t ktime; | |
| 25 | ||
| 26 | /* | |
| 27 | * Refuse to trace from NMIs with this wrapper, because an NMI could | |
| 28 | * nest over the xtime write seqlock and deadlock. | |
| 29 | */ | |
| 30 | if (in_nmi()) | |
| 31 | return 0; | |
| 32 | ||
| 33 | ktime = ktime_get(); | |
| 34 | return (u64) ktime.tv64; | |
| 35 | } | |
| 36 | ||
| 37 | static inline u32 trace_clock_read32(void) | |
| 38 | { | |
| 39 | return (u32) trace_clock_monotonic_wrapper(); | |
| 40 | } | |
| 41 | ||
| 42 | static inline u64 trace_clock_read64(void) | |
| 43 | { | |
| 44 | return (u64) trace_clock_monotonic_wrapper(); | |
| 45 | } | |
| 46 | ||
| 47 | static inline u64 trace_clock_frequency(void) | |
| 48 | { | |
| 49 | return (u64)NSEC_PER_SEC; | |
| 50 | } | |
| 51 | ||
| 52 | static inline u32 trace_clock_freq_scale(void) | |
| 53 | { | |
| 54 | return 1; | |
| 55 | } | |
| 56 | ||
| 57 | static inline int get_trace_clock(void) | |
| 58 | { | |
| 59 | printk(KERN_WARNING "LTTng: Using mainline kernel monotonic clock.\n"); | |
| 60 | printk(KERN_WARNING " * NMIs will not be traced,\n"); | |
| 61 | printk(KERN_WARNING " * expect significant performance degradation compared to the\n"); | |
| 62 | printk(KERN_WARNING " LTTng trace clocks.\n"); | |
| 63 | printk(KERN_WARNING "You should consider deploying a kernel with the the LTTng kernel\n"); | |
| 64 | printk(KERN_WARNING "patches, or, better, ask the Linux tracing maintainers to integrate\n"); | |
| 65 | printk(KERN_WARNING "them if you care deeply about this.\n"); | |
| 66 | return 0; | |
| 67 | } | |
| 68 | ||
| 69 | static inline void put_trace_clock(void) | |
| 70 | { | |
| 71 | } | |
| 72 | ||
| 73 | #endif /* CONFIG_HAVE_TRACE_CLOCK */ | |
| 74 | ||
| 75 | #endif /* _LTT_TRACE_CLOCK_H */ |