Mathieu Desnoyers | fb32e03 | 2008-02-02 15:10:33 -0500 | [diff] [blame] | 1 | # |
| 2 | # General architecture dependent options |
| 3 | # |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 4 | |
| 5 | config OPROFILE |
Robert Richter | b309a29 | 2010-02-26 15:01:23 +0100 | [diff] [blame] | 6 | tristate "OProfile system profiling" |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 7 | depends on PROFILING |
| 8 | depends on HAVE_OPROFILE |
Ingo Molnar | d69d59f | 2008-12-12 09:38:57 +0100 | [diff] [blame] | 9 | select RING_BUFFER |
Christian Borntraeger | 9a5963eb | 2009-09-16 21:56:49 +0200 | [diff] [blame] | 10 | select RING_BUFFER_ALLOW_SWAP |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 11 | help |
| 12 | OProfile is a profiling system capable of profiling the |
| 13 | whole system, include the kernel, kernel modules, libraries, |
| 14 | and applications. |
| 15 | |
| 16 | If unsure, say N. |
| 17 | |
Jason Yeh | 4d4036e | 2009-07-08 13:49:38 +0200 | [diff] [blame] | 18 | config OPROFILE_EVENT_MULTIPLEX |
| 19 | bool "OProfile multiplexing support (EXPERIMENTAL)" |
| 20 | default n |
| 21 | depends on OPROFILE && X86 |
| 22 | help |
| 23 | The number of hardware counters is limited. The multiplexing |
| 24 | feature enables OProfile to gather more events than counters |
| 25 | are provided by the hardware. This is realized by switching |
| 26 | between events at an user specified time interval. |
| 27 | |
| 28 | If unsure, say N. |
| 29 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 30 | config HAVE_OPROFILE |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 31 | bool |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 32 | |
Robert Richter | dcfce4a | 2011-10-11 17:11:08 +0200 | [diff] [blame] | 33 | config OPROFILE_NMI_TIMER |
| 34 | def_bool y |
| 35 | depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
| 36 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 37 | config KPROBES |
| 38 | bool "Kprobes" |
Masami Hiramatsu | 05ed160 | 2010-09-13 19:25:41 +0900 | [diff] [blame] | 39 | depends on MODULES |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 40 | depends on HAVE_KPROBES |
Masami Hiramatsu | 05ed160 | 2010-09-13 19:25:41 +0900 | [diff] [blame] | 41 | select KALLSYMS |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 42 | help |
| 43 | Kprobes allows you to trap at almost any kernel address and |
| 44 | execute a callback function. register_kprobe() establishes |
| 45 | a probepoint and specifies the callback. Kprobes is useful |
| 46 | for kernel debugging, non-intrusive instrumentation and testing. |
| 47 | If in doubt, say "N". |
| 48 | |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 49 | config JUMP_LABEL |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 50 | bool "Optimize very unlikely/likely branches" |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 51 | depends on HAVE_ARCH_JUMP_LABEL |
| 52 | help |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 53 | This option enables a transparent branch optimization that |
| 54 | makes certain almost-always-true or almost-always-false branch |
| 55 | conditions even cheaper to execute within the kernel. |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 56 | |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 57 | Certain performance-sensitive kernel code, such as trace points, |
| 58 | scheduler functionality, networking code and KVM have such |
| 59 | branches and include support for this optimization technique. |
| 60 | |
| 61 | If it is detected that the compiler has support for "asm goto", |
| 62 | the kernel will compile such branches with just a nop |
| 63 | instruction. When the condition flag is toggled to true, the |
| 64 | nop will be converted to a jump instruction to execute the |
| 65 | conditional block of instructions. |
| 66 | |
| 67 | This technique lowers overhead and stress on the branch prediction |
| 68 | of the processor and generally makes the kernel faster. The update |
| 69 | of the condition is slower, but those are always very rare. |
| 70 | |
| 71 | ( On 32-bit x86, the necessary options added to the compiler |
| 72 | flags may increase the size of the kernel slightly. ) |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 73 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 74 | config OPTPROBES |
Masami Hiramatsu | 5cc718b | 2010-03-15 13:00:54 -0400 | [diff] [blame] | 75 | def_bool y |
| 76 | depends on KPROBES && HAVE_OPTPROBES |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 77 | depends on !PREEMPT |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 78 | |
Johannes Berg | 58340a0 | 2008-07-25 01:45:33 -0700 | [diff] [blame] | 79 | config HAVE_EFFICIENT_UNALIGNED_ACCESS |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 80 | bool |
Johannes Berg | 58340a0 | 2008-07-25 01:45:33 -0700 | [diff] [blame] | 81 | help |
| 82 | Some architectures are unable to perform unaligned accesses |
| 83 | without the use of get_unaligned/put_unaligned. Others are |
| 84 | unable to perform such accesses efficiently (e.g. trap on |
| 85 | unaligned access and require fixing it up in the exception |
| 86 | handler.) |
| 87 | |
| 88 | This symbol should be selected by an architecture if it can |
| 89 | perform unaligned accesses efficiently to allow different |
| 90 | code paths to be selected for these cases. Some network |
| 91 | drivers, for example, could opt to not fix up alignment |
| 92 | problems with received packets if doing so would not help |
| 93 | much. |
| 94 | |
| 95 | See Documentation/unaligned-memory-access.txt for more |
| 96 | information on the topic of unaligned memory accesses. |
| 97 | |
Heiko Carstens | 1a94bc3 | 2009-01-14 14:13:59 +0100 | [diff] [blame] | 98 | config HAVE_SYSCALL_WRAPPERS |
| 99 | bool |
| 100 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 101 | config KRETPROBES |
| 102 | def_bool y |
| 103 | depends on KPROBES && HAVE_KRETPROBES |
| 104 | |
Avi Kivity | 7c68af6 | 2009-09-19 09:40:22 +0300 | [diff] [blame] | 105 | config USER_RETURN_NOTIFIER |
| 106 | bool |
| 107 | depends on HAVE_USER_RETURN_NOTIFIER |
| 108 | help |
| 109 | Provide a kernel-internal notification when a cpu is about to |
| 110 | switch to user mode. |
| 111 | |
Rik van Riel | 28b2ee2 | 2008-07-23 21:27:05 -0700 | [diff] [blame] | 112 | config HAVE_IOREMAP_PROT |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 113 | bool |
Rik van Riel | 28b2ee2 | 2008-07-23 21:27:05 -0700 | [diff] [blame] | 114 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 115 | config HAVE_KPROBES |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 116 | bool |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 117 | |
| 118 | config HAVE_KRETPROBES |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 119 | bool |
Arthur Kepner | 74bc7ce | 2008-04-29 01:00:30 -0700 | [diff] [blame] | 120 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 121 | config HAVE_OPTPROBES |
| 122 | bool |
Cong Wang | d314d74 | 2012-03-23 15:01:51 -0700 | [diff] [blame] | 123 | |
| 124 | config HAVE_NMI_WATCHDOG |
| 125 | bool |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 126 | # |
| 127 | # An arch should select this if it provides all these things: |
| 128 | # |
| 129 | # task_pt_regs() in asm/processor.h or asm/ptrace.h |
| 130 | # arch_has_single_step() if there is hardware single-step support |
| 131 | # arch_has_block_step() if there is hardware block-step support |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 132 | # asm/syscall.h supplying asm-generic/syscall.h interface |
| 133 | # linux/regset.h user_regset interfaces |
| 134 | # CORE_DUMP_USE_REGSET #define'd in linux/elf.h |
| 135 | # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} |
| 136 | # TIF_NOTIFY_RESUME calls tracehook_notify_resume() |
| 137 | # signal delivery calls tracehook_signal_handler() |
| 138 | # |
| 139 | config HAVE_ARCH_TRACEHOOK |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 140 | bool |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 141 | |
Arthur Kepner | 74bc7ce | 2008-04-29 01:00:30 -0700 | [diff] [blame] | 142 | config HAVE_DMA_ATTRS |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 143 | bool |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 144 | |
| 145 | config USE_GENERIC_SMP_HELPERS |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 146 | bool |
David Brownell | 9483a57 | 2008-07-23 21:26:48 -0700 | [diff] [blame] | 147 | |
Thomas Gleixner | 29d5e04 | 2012-04-20 13:05:45 +0000 | [diff] [blame^] | 148 | config GENERIC_SMP_IDLE_THREAD |
| 149 | bool |
| 150 | |
Heiko Carstens | f850c30c | 2010-02-10 17:25:17 +0100 | [diff] [blame] | 151 | config HAVE_REGS_AND_STACK_ACCESS_API |
| 152 | bool |
Heiko Carstens | e01292b | 2010-02-18 14:25:21 +0100 | [diff] [blame] | 153 | help |
| 154 | This symbol should be selected by an architecure if it supports |
| 155 | the API needed to access registers and stack entries from pt_regs, |
| 156 | declared in asm/ptrace.h |
| 157 | For example the kprobes-based event tracer needs this API. |
Heiko Carstens | f850c30c | 2010-02-10 17:25:17 +0100 | [diff] [blame] | 158 | |
David Brownell | 9483a57 | 2008-07-23 21:26:48 -0700 | [diff] [blame] | 159 | config HAVE_CLK |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 160 | bool |
David Brownell | 9483a57 | 2008-07-23 21:26:48 -0700 | [diff] [blame] | 161 | help |
| 162 | The <linux/clk.h> calls support software clock gating and |
| 163 | thus are a key power management tool on many systems. |
| 164 | |
Joerg Roedel | 5ee00bd | 2009-01-09 12:14:24 +0100 | [diff] [blame] | 165 | config HAVE_DMA_API_DEBUG |
| 166 | bool |
Heiko Carstens | 36cd3c9 | 2009-04-09 18:48:34 +0200 | [diff] [blame] | 167 | |
K.Prasad | 62a038d | 2009-06-01 23:43:33 +0530 | [diff] [blame] | 168 | config HAVE_HW_BREAKPOINT |
| 169 | bool |
Frederic Weisbecker | 99e8c5a | 2009-12-17 01:33:54 +0100 | [diff] [blame] | 170 | depends on PERF_EVENTS |
K.Prasad | 62a038d | 2009-06-01 23:43:33 +0530 | [diff] [blame] | 171 | |
Frederic Weisbecker | 0102752 | 2010-04-11 18:55:56 +0200 | [diff] [blame] | 172 | config HAVE_MIXED_BREAKPOINTS_REGS |
| 173 | bool |
| 174 | depends on HAVE_HW_BREAKPOINT |
| 175 | help |
| 176 | Depending on the arch implementation of hardware breakpoints, |
| 177 | some of them have separate registers for data and instruction |
| 178 | breakpoints addresses, others have mixed registers to store |
| 179 | them but define the access type in a control register. |
| 180 | Select this option if your arch implements breakpoints under the |
| 181 | latter fashion. |
| 182 | |
Avi Kivity | 7c68af6 | 2009-09-19 09:40:22 +0300 | [diff] [blame] | 183 | config HAVE_USER_RETURN_NOTIFIER |
| 184 | bool |
Ingo Molnar | a1922ed | 2009-09-07 08:19:51 +0200 | [diff] [blame] | 185 | |
Frederic Weisbecker | c01d432 | 2010-05-15 22:57:48 +0200 | [diff] [blame] | 186 | config HAVE_PERF_EVENTS_NMI |
| 187 | bool |
Frederic Weisbecker | 23637d4 | 2010-05-15 23:15:20 +0200 | [diff] [blame] | 188 | help |
| 189 | System hardware can generate an NMI using the perf event |
| 190 | subsystem. Also has support for calculating CPU cycle events |
| 191 | to determine how many clock cycles in a given period. |
Frederic Weisbecker | c01d432 | 2010-05-15 22:57:48 +0200 | [diff] [blame] | 192 | |
Jason Baron | bf5438fc | 2010-09-17 11:09:00 -0400 | [diff] [blame] | 193 | config HAVE_ARCH_JUMP_LABEL |
| 194 | bool |
| 195 | |
Gerald Schaefer | 335d7af | 2010-11-22 15:47:36 +0100 | [diff] [blame] | 196 | config HAVE_ARCH_MUTEX_CPU_RELAX |
| 197 | bool |
| 198 | |
Peter Zijlstra | 2672391 | 2011-05-24 17:12:00 -0700 | [diff] [blame] | 199 | config HAVE_RCU_TABLE_FREE |
| 200 | bool |
| 201 | |
Huang Ying | df013ff | 2011-07-13 13:14:22 +0800 | [diff] [blame] | 202 | config ARCH_HAVE_NMI_SAFE_CMPXCHG |
| 203 | bool |
| 204 | |
Heiko Carstens | 43570fd | 2012-01-12 17:17:27 -0800 | [diff] [blame] | 205 | config HAVE_ALIGNED_STRUCT_PAGE |
| 206 | bool |
| 207 | help |
| 208 | This makes sure that struct pages are double word aligned and that |
| 209 | e.g. the SLUB allocator can perform double word atomic operations |
| 210 | on a struct page for better performance. However selecting this |
| 211 | might increase the size of a struct page by a word. |
| 212 | |
Heiko Carstens | 4156153 | 2012-01-12 17:17:30 -0800 | [diff] [blame] | 213 | config HAVE_CMPXCHG_LOCAL |
| 214 | bool |
| 215 | |
Heiko Carstens | 2565409 | 2012-01-12 17:17:33 -0800 | [diff] [blame] | 216 | config HAVE_CMPXCHG_DOUBLE |
| 217 | bool |
| 218 | |
Chris Metcalf | 48b25c4 | 2012-03-15 13:13:38 -0400 | [diff] [blame] | 219 | config ARCH_WANT_OLD_COMPAT_IPC |
| 220 | bool |
| 221 | |
Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 222 | source "kernel/gcov/Kconfig" |