Commit | Line | Data |
---|---|---|
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 | |
58340a07 | 79 | config HAVE_EFFICIENT_UNALIGNED_ACCESS |
9ba16087 | 80 | bool |
58340a07 JB |
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 | ||
1a94bc34 HC |
98 | config HAVE_SYSCALL_WRAPPERS |
99 | bool | |
100 | ||
9edddaa2 AM |
101 | config KRETPROBES |
102 | def_bool y | |
103 | depends on KPROBES && HAVE_KRETPROBES | |
104 | ||
7c68af6e AK |
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 | ||
28b2ee20 | 112 | config HAVE_IOREMAP_PROT |
9ba16087 | 113 | bool |
28b2ee20 | 114 | |
125e5645 | 115 | config HAVE_KPROBES |
9ba16087 | 116 | bool |
9edddaa2 AM |
117 | |
118 | config HAVE_KRETPROBES | |
9ba16087 | 119 | bool |
74bc7cee | 120 | |
afd66255 MH |
121 | config HAVE_OPTPROBES |
122 | bool | |
d314d74c CW |
123 | |
124 | config HAVE_NMI_WATCHDOG | |
125 | bool | |
1f5a4ad9 RM |
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 | |
1f5a4ad9 RM |
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 | |
9ba16087 | 140 | bool |
1f5a4ad9 | 141 | |
74bc7cee | 142 | config HAVE_DMA_ATTRS |
9ba16087 | 143 | bool |
3d442233 JA |
144 | |
145 | config USE_GENERIC_SMP_HELPERS | |
9ba16087 | 146 | bool |
9483a578 | 147 | |
29d5e047 TG |
148 | config GENERIC_SMP_IDLE_THREAD |
149 | bool | |
150 | ||
a6359d1e TG |
151 | # Select if arch init_task initializer is different to init/init_task.c |
152 | config ARCH_INIT_TASK | |
a4a2eb49 TG |
153 | bool |
154 | ||
f5e10287 TG |
155 | # Select if arch has its private alloc_task_struct() function |
156 | config ARCH_TASK_STRUCT_ALLOCATOR | |
157 | bool | |
158 | ||
159 | # Select if arch has its private alloc_thread_info() function | |
160 | config ARCH_THREAD_INFO_ALLOCATOR | |
161 | bool | |
162 | ||
f850c30c HC |
163 | config HAVE_REGS_AND_STACK_ACCESS_API |
164 | bool | |
e01292b1 HC |
165 | help |
166 | This symbol should be selected by an architecure if it supports | |
167 | the API needed to access registers and stack entries from pt_regs, | |
168 | declared in asm/ptrace.h | |
169 | For example the kprobes-based event tracer needs this API. | |
f850c30c | 170 | |
9483a578 | 171 | config HAVE_CLK |
9ba16087 | 172 | bool |
9483a578 DB |
173 | help |
174 | The <linux/clk.h> calls support software clock gating and | |
175 | thus are a key power management tool on many systems. | |
176 | ||
5ee00bd4 JR |
177 | config HAVE_DMA_API_DEBUG |
178 | bool | |
36cd3c9f | 179 | |
62a038d3 P |
180 | config HAVE_HW_BREAKPOINT |
181 | bool | |
99e8c5a3 | 182 | depends on PERF_EVENTS |
62a038d3 | 183 | |
0102752e FW |
184 | config HAVE_MIXED_BREAKPOINTS_REGS |
185 | bool | |
186 | depends on HAVE_HW_BREAKPOINT | |
187 | help | |
188 | Depending on the arch implementation of hardware breakpoints, | |
189 | some of them have separate registers for data and instruction | |
190 | breakpoints addresses, others have mixed registers to store | |
191 | them but define the access type in a control register. | |
192 | Select this option if your arch implements breakpoints under the | |
193 | latter fashion. | |
194 | ||
7c68af6e AK |
195 | config HAVE_USER_RETURN_NOTIFIER |
196 | bool | |
a1922ed6 | 197 | |
c01d4323 FW |
198 | config HAVE_PERF_EVENTS_NMI |
199 | bool | |
23637d47 FW |
200 | help |
201 | System hardware can generate an NMI using the perf event | |
202 | subsystem. Also has support for calculating CPU cycle events | |
203 | to determine how many clock cycles in a given period. | |
c01d4323 | 204 | |
bf5438fc JB |
205 | config HAVE_ARCH_JUMP_LABEL |
206 | bool | |
207 | ||
335d7afb GS |
208 | config HAVE_ARCH_MUTEX_CPU_RELAX |
209 | bool | |
210 | ||
26723911 PZ |
211 | config HAVE_RCU_TABLE_FREE |
212 | bool | |
213 | ||
df013ffb HY |
214 | config ARCH_HAVE_NMI_SAFE_CMPXCHG |
215 | bool | |
216 | ||
43570fd2 HC |
217 | config HAVE_ALIGNED_STRUCT_PAGE |
218 | bool | |
219 | help | |
220 | This makes sure that struct pages are double word aligned and that | |
221 | e.g. the SLUB allocator can perform double word atomic operations | |
222 | on a struct page for better performance. However selecting this | |
223 | might increase the size of a struct page by a word. | |
224 | ||
4156153c HC |
225 | config HAVE_CMPXCHG_LOCAL |
226 | bool | |
227 | ||
2565409f HC |
228 | config HAVE_CMPXCHG_DOUBLE |
229 | bool | |
230 | ||
48b25c43 CM |
231 | config ARCH_WANT_OLD_COMPAT_IPC |
232 | bool | |
233 | ||
e2cfabdf WD |
234 | config HAVE_ARCH_SECCOMP_FILTER |
235 | bool | |
236 | help | |
fb0fadf9 | 237 | An arch should select this symbol if it provides all of these things: |
bb6ea430 WD |
238 | - syscall_get_arch() |
239 | - syscall_get_arguments() | |
240 | - syscall_rollback() | |
241 | - syscall_set_return_value() | |
fb0fadf9 WD |
242 | - SIGSYS siginfo_t support |
243 | - secure_computing is called from a ptrace_event()-safe context | |
244 | - secure_computing return value is checked and a return value of -1 | |
245 | results in the system call being skipped immediately. | |
e2cfabdf WD |
246 | |
247 | config SECCOMP_FILTER | |
248 | def_bool y | |
249 | depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET | |
250 | help | |
251 | Enable tasks to build secure computing environments defined | |
252 | in terms of Berkeley Packet Filter programs which implement | |
253 | task-defined system call filtering polices. | |
254 | ||
255 | See Documentation/prctl/seccomp_filter.txt for details. | |
256 | ||
2521f2c2 | 257 | source "kernel/gcov/Kconfig" |