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518d7abb PMF |
1 | /* Copyright (C) 2010 Pierre-Marc Fournier |
2 | * | |
3 | * This library is free software; you can redistribute it and/or | |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
7 | * | |
8 | * This library is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * Lesser General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Lesser General Public | |
14 | * License along with this library; if not, write to the Free Software | |
15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
18 | #ifndef UST_CLOCK_H | |
19 | #define UST_CLOCK_H | |
20 | ||
21 | #include <sys/time.h> | |
22 | #include <ust/kcompat/kcompat.h> | |
23 | ||
24 | /* TRACE CLOCK */ | |
25 | ||
26 | /* There are two types of clocks that can be used. | |
27 | - TSC based clock | |
28 | - gettimeofday() clock | |
29 | ||
30 | Microbenchmarks on Linux 2.6.30 on Core2 Duo 3GHz (functions are inlined): | |
31 | Calls (100000000) to tsc(): 4004035641 cycles or 40 cycles/call | |
32 | Calls (100000000) to gettimeofday(): 9723158352 cycles or 97 cycles/call | |
33 | ||
34 | For merging traces with the kernel, a time source compatible with that of | |
35 | the kernel is necessary. | |
36 | ||
37 | */ | |
38 | ||
39 | #define TRACE_CLOCK_GENERIC | |
40 | #ifdef TRACE_CLOCK_GENERIC | |
41 | ||
42 | static __inline__ u64 trace_clock_read64(void) | |
43 | { | |
44 | struct timeval tv; | |
45 | u64 retval; | |
46 | ||
47 | gettimeofday(&tv, NULL); | |
48 | retval = tv.tv_sec; | |
49 | retval *= 1000000; | |
50 | retval += tv.tv_usec; | |
51 | ||
52 | return retval; | |
53 | } | |
54 | ||
55 | #else | |
56 | ||
57 | #if __i386 || __x86_64 | |
58 | ||
59 | /* WARNING: Make sure to set frequency and scaling functions that will not | |
60 | * result in lttv timestamps (sec.nsec) with seconds greater than 2**32-1. | |
61 | */ | |
62 | static __inline__ u64 trace_clock_read64(void) | |
63 | { | |
64 | uint32_t low; | |
65 | uint32_t high; | |
66 | uint64_t retval; | |
67 | __asm__ volatile ("rdtsc\n" : "=a" (low), "=d" (high)); | |
68 | ||
69 | retval = high; | |
70 | retval <<= 32; | |
71 | return retval | low; | |
72 | } | |
73 | ||
74 | #endif /* __i386 || __x86_64 */ | |
75 | ||
76 | #ifdef __PPC__ | |
77 | ||
78 | static __inline__ u64 trace_clock_read64(void) | |
79 | { | |
80 | unsigned long tb_l; | |
81 | unsigned long tb_h; | |
82 | unsigned long tb_h2; | |
83 | u64 tb; | |
84 | ||
85 | __asm__ ( | |
86 | "1:\n\t" | |
87 | "mftbu %[rhigh]\n\t" | |
88 | "mftb %[rlow]\n\t" | |
89 | "mftbu %[rhigh2]\n\t" | |
90 | "cmpw %[rhigh],%[rhigh2]\n\t" | |
91 | "bne 1b\n\t" | |
92 | : [rhigh] "=r" (tb_h), [rhigh2] "=r" (tb_h2), [rlow] "=r" (tb_l)); | |
93 | ||
94 | tb = tb_h; | |
95 | tb <<= 32; | |
96 | tb |= tb_l; | |
97 | ||
98 | return tb; | |
99 | } | |
100 | ||
101 | #endif /* __PPC__ */ | |
102 | ||
103 | #endif /* ! UST_TRACE_CLOCK_GENERIC */ | |
104 | ||
105 | static __inline__ u64 trace_clock_frequency(void) | |
106 | { | |
107 | return 1000000LL; | |
108 | } | |
109 | ||
110 | static __inline__ u32 trace_clock_freq_scale(void) | |
111 | { | |
112 | return 1; | |
113 | } | |
114 | ||
115 | #endif /* UST_CLOCK_H */ |