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Commit | Line | Data |
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fb32e03f MD |
1 | # |
2 | # General architecture dependent options | |
3 | # | |
125e5645 MD |
4 | |
5 | config OPROFILE | |
b309a294 | 6 | tristate "OProfile system profiling" |
125e5645 MD |
7 | depends on PROFILING |
8 | depends on HAVE_OPROFILE | |
d69d59f4 | 9 | select RING_BUFFER |
9a5963eb | 10 | select RING_BUFFER_ALLOW_SWAP |
125e5645 MD |
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 | ||
4d4036e0 JY |
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 | ||
125e5645 | 30 | config HAVE_OPROFILE |
9ba16087 | 31 | bool |
125e5645 | 32 | |
dcfce4a0 RR |
33 | config OPROFILE_NMI_TIMER |
34 | def_bool y | |
35 | depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI | |
36 | ||
125e5645 MD |
37 | config KPROBES |
38 | bool "Kprobes" | |
05ed160e | 39 | depends on MODULES |
125e5645 | 40 | depends on HAVE_KPROBES |
05ed160e | 41 | select KALLSYMS |
125e5645 MD |
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 | ||
45f81b1c | 49 | config JUMP_LABEL |
c5905afb | 50 | bool "Optimize very unlikely/likely branches" |
45f81b1c SR |
51 | depends on HAVE_ARCH_JUMP_LABEL |
52 | help | |
c5905afb IM |
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. | |
56 | ||
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 | ||
45f81b1c | 61 | If it is detected that the compiler has support for "asm goto", |
c5905afb IM |
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. | |
45f81b1c | 70 | |
c5905afb IM |
71 | ( On 32-bit x86, the necessary options added to the compiler |
72 | flags may increase the size of the kernel slightly. ) | |
45f81b1c | 73 | |
afd66255 | 74 | config OPTPROBES |
5cc718b9 MH |
75 | def_bool y |
76 | depends on KPROBES && HAVE_OPTPROBES | |
afd66255 | 77 | depends on !PREEMPT |
afd66255 | 78 | |
2b144498 | 79 | config UPROBES |
7b2d81d4 | 80 | bool "Transparent user-space probes (EXPERIMENTAL)" |
ec83db0f | 81 | depends on UPROBE_EVENT && PERF_EVENTS |
2b144498 SD |
82 | default n |
83 | help | |
7b2d81d4 IM |
84 | Uprobes is the user-space counterpart to kprobes: they |
85 | enable instrumentation applications (such as 'perf probe') | |
86 | to establish unintrusive probes in user-space binaries and | |
87 | libraries, by executing handler functions when the probes | |
88 | are hit by user-space applications. | |
89 | ||
90 | ( These probes come in the form of single-byte breakpoints, | |
91 | managed by the kernel and kept transparent to the probed | |
92 | application. ) | |
2b144498 SD |
93 | |
94 | If in doubt, say "N". | |
95 | ||
58340a07 | 96 | config HAVE_EFFICIENT_UNALIGNED_ACCESS |
9ba16087 | 97 | bool |
58340a07 JB |
98 | help |
99 | Some architectures are unable to perform unaligned accesses | |
100 | without the use of get_unaligned/put_unaligned. Others are | |
101 | unable to perform such accesses efficiently (e.g. trap on | |
102 | unaligned access and require fixing it up in the exception | |
103 | handler.) | |
104 | ||
105 | This symbol should be selected by an architecture if it can | |
106 | perform unaligned accesses efficiently to allow different | |
107 | code paths to be selected for these cases. Some network | |
108 | drivers, for example, could opt to not fix up alignment | |
109 | problems with received packets if doing so would not help | |
110 | much. | |
111 | ||
112 | See Documentation/unaligned-memory-access.txt for more | |
113 | information on the topic of unaligned memory accesses. | |
114 | ||
1a94bc34 HC |
115 | config HAVE_SYSCALL_WRAPPERS |
116 | bool | |
117 | ||
9edddaa2 AM |
118 | config KRETPROBES |
119 | def_bool y | |
120 | depends on KPROBES && HAVE_KRETPROBES | |
121 | ||
7c68af6e AK |
122 | config USER_RETURN_NOTIFIER |
123 | bool | |
124 | depends on HAVE_USER_RETURN_NOTIFIER | |
125 | help | |
126 | Provide a kernel-internal notification when a cpu is about to | |
127 | switch to user mode. | |
128 | ||
28b2ee20 | 129 | config HAVE_IOREMAP_PROT |
9ba16087 | 130 | bool |
28b2ee20 | 131 | |
125e5645 | 132 | config HAVE_KPROBES |
9ba16087 | 133 | bool |
9edddaa2 AM |
134 | |
135 | config HAVE_KRETPROBES | |
9ba16087 | 136 | bool |
74bc7cee | 137 | |
afd66255 MH |
138 | config HAVE_OPTPROBES |
139 | bool | |
d314d74c CW |
140 | |
141 | config HAVE_NMI_WATCHDOG | |
142 | bool | |
1f5a4ad9 RM |
143 | # |
144 | # An arch should select this if it provides all these things: | |
145 | # | |
146 | # task_pt_regs() in asm/processor.h or asm/ptrace.h | |
147 | # arch_has_single_step() if there is hardware single-step support | |
148 | # arch_has_block_step() if there is hardware block-step support | |
1f5a4ad9 RM |
149 | # asm/syscall.h supplying asm-generic/syscall.h interface |
150 | # linux/regset.h user_regset interfaces | |
151 | # CORE_DUMP_USE_REGSET #define'd in linux/elf.h | |
152 | # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} | |
153 | # TIF_NOTIFY_RESUME calls tracehook_notify_resume() | |
154 | # signal delivery calls tracehook_signal_handler() | |
155 | # | |
156 | config HAVE_ARCH_TRACEHOOK | |
9ba16087 | 157 | bool |
1f5a4ad9 | 158 | |
74bc7cee | 159 | config HAVE_DMA_ATTRS |
9ba16087 | 160 | bool |
3d442233 | 161 | |
c64be2bb MS |
162 | config HAVE_DMA_CONTIGUOUS |
163 | bool | |
164 | ||
3d442233 | 165 | config USE_GENERIC_SMP_HELPERS |
9ba16087 | 166 | bool |
9483a578 | 167 | |
29d5e047 TG |
168 | config GENERIC_SMP_IDLE_THREAD |
169 | bool | |
170 | ||
a6359d1e TG |
171 | # Select if arch init_task initializer is different to init/init_task.c |
172 | config ARCH_INIT_TASK | |
a4a2eb49 TG |
173 | bool |
174 | ||
f5e10287 TG |
175 | # Select if arch has its private alloc_task_struct() function |
176 | config ARCH_TASK_STRUCT_ALLOCATOR | |
177 | bool | |
178 | ||
179 | # Select if arch has its private alloc_thread_info() function | |
180 | config ARCH_THREAD_INFO_ALLOCATOR | |
181 | bool | |
182 | ||
f850c30c HC |
183 | config HAVE_REGS_AND_STACK_ACCESS_API |
184 | bool | |
e01292b1 HC |
185 | help |
186 | This symbol should be selected by an architecure if it supports | |
187 | the API needed to access registers and stack entries from pt_regs, | |
188 | declared in asm/ptrace.h | |
189 | For example the kprobes-based event tracer needs this API. | |
f850c30c | 190 | |
9483a578 | 191 | config HAVE_CLK |
9ba16087 | 192 | bool |
9483a578 DB |
193 | help |
194 | The <linux/clk.h> calls support software clock gating and | |
195 | thus are a key power management tool on many systems. | |
196 | ||
5ee00bd4 JR |
197 | config HAVE_DMA_API_DEBUG |
198 | bool | |
36cd3c9f | 199 | |
62a038d3 P |
200 | config HAVE_HW_BREAKPOINT |
201 | bool | |
99e8c5a3 | 202 | depends on PERF_EVENTS |
62a038d3 | 203 | |
0102752e FW |
204 | config HAVE_MIXED_BREAKPOINTS_REGS |
205 | bool | |
206 | depends on HAVE_HW_BREAKPOINT | |
207 | help | |
208 | Depending on the arch implementation of hardware breakpoints, | |
209 | some of them have separate registers for data and instruction | |
210 | breakpoints addresses, others have mixed registers to store | |
211 | them but define the access type in a control register. | |
212 | Select this option if your arch implements breakpoints under the | |
213 | latter fashion. | |
214 | ||
7c68af6e AK |
215 | config HAVE_USER_RETURN_NOTIFIER |
216 | bool | |
a1922ed6 | 217 | |
c01d4323 FW |
218 | config HAVE_PERF_EVENTS_NMI |
219 | bool | |
23637d47 FW |
220 | help |
221 | System hardware can generate an NMI using the perf event | |
222 | subsystem. Also has support for calculating CPU cycle events | |
223 | to determine how many clock cycles in a given period. | |
c01d4323 | 224 | |
c5e63197 JO |
225 | config HAVE_PERF_REGS |
226 | bool | |
227 | help | |
228 | Support selective register dumps for perf events. This includes | |
229 | bit-mapping of each registers and a unique architecture id. | |
230 | ||
bf5438fc JB |
231 | config HAVE_ARCH_JUMP_LABEL |
232 | bool | |
233 | ||
335d7afb GS |
234 | config HAVE_ARCH_MUTEX_CPU_RELAX |
235 | bool | |
236 | ||
26723911 PZ |
237 | config HAVE_RCU_TABLE_FREE |
238 | bool | |
239 | ||
df013ffb HY |
240 | config ARCH_HAVE_NMI_SAFE_CMPXCHG |
241 | bool | |
242 | ||
43570fd2 HC |
243 | config HAVE_ALIGNED_STRUCT_PAGE |
244 | bool | |
245 | help | |
246 | This makes sure that struct pages are double word aligned and that | |
247 | e.g. the SLUB allocator can perform double word atomic operations | |
248 | on a struct page for better performance. However selecting this | |
249 | might increase the size of a struct page by a word. | |
250 | ||
4156153c HC |
251 | config HAVE_CMPXCHG_LOCAL |
252 | bool | |
253 | ||
2565409f HC |
254 | config HAVE_CMPXCHG_DOUBLE |
255 | bool | |
256 | ||
c1d7e01d WD |
257 | config ARCH_WANT_IPC_PARSE_VERSION |
258 | bool | |
259 | ||
260 | config ARCH_WANT_COMPAT_IPC_PARSE_VERSION | |
261 | bool | |
262 | ||
48b25c43 | 263 | config ARCH_WANT_OLD_COMPAT_IPC |
c1d7e01d | 264 | select ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
48b25c43 CM |
265 | bool |
266 | ||
e2cfabdf WD |
267 | config HAVE_ARCH_SECCOMP_FILTER |
268 | bool | |
269 | help | |
fb0fadf9 | 270 | An arch should select this symbol if it provides all of these things: |
bb6ea430 WD |
271 | - syscall_get_arch() |
272 | - syscall_get_arguments() | |
273 | - syscall_rollback() | |
274 | - syscall_set_return_value() | |
fb0fadf9 WD |
275 | - SIGSYS siginfo_t support |
276 | - secure_computing is called from a ptrace_event()-safe context | |
277 | - secure_computing return value is checked and a return value of -1 | |
278 | results in the system call being skipped immediately. | |
e2cfabdf WD |
279 | |
280 | config SECCOMP_FILTER | |
281 | def_bool y | |
282 | depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET | |
283 | help | |
284 | Enable tasks to build secure computing environments defined | |
285 | in terms of Berkeley Packet Filter programs which implement | |
286 | task-defined system call filtering polices. | |
287 | ||
288 | See Documentation/prctl/seccomp_filter.txt for details. | |
289 | ||
2521f2c2 | 290 | source "kernel/gcov/Kconfig" |