projects / lttng-ust.git / blame
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|---|---|---|
| 2b2d6ff7 MD |
1 | #ifndef _LTTNG_GETCPU_H |
| 2 | #define _LTTNG_GETCPU_H | |
| 3 | ||
| 4 | /* | |
| 5 | * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 6 | * | |
| 7 | * This library is free software; you can redistribute it and/or | |
| 8 | * modify it under the terms of the GNU Lesser General Public | |
| 9 | * License as published by the Free Software Foundation; only | |
| 10 | * version 2.1 of the License. | |
| 11 | * | |
| 12 | * This library is distributed in the hope that it will be useful, | |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 | * Lesser General Public License for more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU Lesser General Public | |
| 18 | * License along with this library; if not, write to the Free Software | |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 20 | */ | |
| 21 | ||
| 2b2d6ff7 | 22 | #include <urcu/compiler.h> |
| 2b2d6ff7 | 23 | |
| fdb4af10 | 24 | #ifdef LTTNG_UST_DEBUG_VALGRIND |
| 2b2d6ff7 MD |
25 | |
| 26 | /* | |
| 27 | * Fallback on cpu 0 if liblttng-ust is build with Valgrind support. | |
| 28 | * get_cpu() returns the current CPU number. It may change due to | |
| 29 | * migration, so it is only statistically accurate. | |
| 30 | */ | |
| 31 | static inline | |
| 32 | int lttng_ust_get_cpu(void) | |
| 33 | { | |
| 34 | return 0; | |
| 35 | } | |
| 36 | ||
| 37 | #else | |
| 38 | ||
| bfe459fb MD |
39 | /* |
| 40 | * sched_getcpu. | |
| 41 | */ | |
| 42 | #ifdef __linux__ | |
| 43 | ||
| 44 | #ifdef __UCLIBC__ | |
| 45 | #include <sys/syscall.h> | |
| 46 | #define __getcpu(cpu, node, cache) syscall(__NR_getcpu, cpu, node, cache) | |
| 47 | /* | |
| 48 | * If getcpu is not implemented in the kernel, use cpu 0 as fallback. | |
| 49 | */ | |
| 50 | static inline | |
| 51 | int lttng_ust_get_cpu(void) | |
| 52 | { | |
| 53 | int cpu, ret; | |
| 54 | ||
| 55 | ret = __getcpu(&cpu, NULL, NULL); | |
| 56 | if (caa_unlikely(ret < 0)) | |
| 57 | return 0; | |
| 58 | return c; | |
| 59 | } | |
| 60 | #else /* __UCLIBC__ */ | |
| 61 | #include <sched.h> | |
| 62 | ||
| 2b2d6ff7 MD |
63 | /* |
| 64 | * If getcpu is not implemented in the kernel, use cpu 0 as fallback. | |
| 65 | */ | |
| 66 | static inline | |
| 67 | int lttng_ust_get_cpu(void) | |
| 68 | { | |
| 69 | int cpu; | |
| 70 | ||
| 71 | cpu = sched_getcpu(); | |
| 72 | if (caa_unlikely(cpu < 0)) | |
| 73 | return 0; | |
| 74 | return cpu; | |
| 75 | } | |
| bfe459fb MD |
76 | #endif /* __UCLIBC__ */ |
| 77 | ||
| 4b36962f | 78 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__)) |
| bfe459fb MD |
79 | |
| 80 | /* | |
| 4b36962f MD |
81 | * FreeBSD and Cygwin do not allow query of CPU ID. Always use CPU |
| 82 | * number 0, with the assocated performance degradation on SMP. | |
| bfe459fb MD |
83 | */ |
| 84 | static inline | |
| 85 | int lttng_ust_get_cpu(void) | |
| 86 | { | |
| 87 | return 0; | |
| 88 | } | |
| 89 | ||
| 90 | #else | |
| 91 | #error "Please add support for your OS into liblttng-ust/compat.h." | |
| 92 | #endif | |
| 2b2d6ff7 MD |
93 | |
| 94 | #endif | |
| 95 | ||
| 96 | #endif /* _LTTNG_GETCPU_H */ |