xref: /linux/arch/Kconfig (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1#
2# General architecture dependent options
3#
4
5config OPROFILE
6	tristate "OProfile system profiling"
7	depends on PROFILING
8	depends on HAVE_OPROFILE
9	select RING_BUFFER
10	select RING_BUFFER_ALLOW_SWAP
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
18config 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
30config HAVE_OPROFILE
31	bool
32
33config OPROFILE_NMI_TIMER
34	def_bool y
35	depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI
36
37config KPROBES
38	bool "Kprobes"
39	depends on MODULES
40	depends on HAVE_KPROBES
41	select KALLSYMS
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
49config JUMP_LABEL
50       bool "Optimize trace point call sites"
51       depends on HAVE_ARCH_JUMP_LABEL
52       help
53         If it is detected that the compiler has support for "asm goto",
54	 the kernel will compile trace point locations with just a
55	 nop instruction. When trace points are enabled, the nop will
56	 be converted to a jump to the trace function. This technique
57	 lowers overhead and stress on the branch prediction of the
58	 processor.
59
60	 On i386, options added to the compiler flags may increase
61	 the size of the kernel slightly.
62
63config OPTPROBES
64	def_bool y
65	depends on KPROBES && HAVE_OPTPROBES
66	depends on !PREEMPT
67
68config HAVE_EFFICIENT_UNALIGNED_ACCESS
69	bool
70	help
71	  Some architectures are unable to perform unaligned accesses
72	  without the use of get_unaligned/put_unaligned. Others are
73	  unable to perform such accesses efficiently (e.g. trap on
74	  unaligned access and require fixing it up in the exception
75	  handler.)
76
77	  This symbol should be selected by an architecture if it can
78	  perform unaligned accesses efficiently to allow different
79	  code paths to be selected for these cases. Some network
80	  drivers, for example, could opt to not fix up alignment
81	  problems with received packets if doing so would not help
82	  much.
83
84	  See Documentation/unaligned-memory-access.txt for more
85	  information on the topic of unaligned memory accesses.
86
87config HAVE_SYSCALL_WRAPPERS
88	bool
89
90config KRETPROBES
91	def_bool y
92	depends on KPROBES && HAVE_KRETPROBES
93
94config USER_RETURN_NOTIFIER
95	bool
96	depends on HAVE_USER_RETURN_NOTIFIER
97	help
98	  Provide a kernel-internal notification when a cpu is about to
99	  switch to user mode.
100
101config HAVE_IOREMAP_PROT
102	bool
103
104config HAVE_KPROBES
105	bool
106
107config HAVE_KRETPROBES
108	bool
109
110config HAVE_OPTPROBES
111	bool
112#
113# An arch should select this if it provides all these things:
114#
115#	task_pt_regs()		in asm/processor.h or asm/ptrace.h
116#	arch_has_single_step()	if there is hardware single-step support
117#	arch_has_block_step()	if there is hardware block-step support
118#	asm/syscall.h		supplying asm-generic/syscall.h interface
119#	linux/regset.h		user_regset interfaces
120#	CORE_DUMP_USE_REGSET	#define'd in linux/elf.h
121#	TIF_SYSCALL_TRACE	calls tracehook_report_syscall_{entry,exit}
122#	TIF_NOTIFY_RESUME	calls tracehook_notify_resume()
123#	signal delivery		calls tracehook_signal_handler()
124#
125config HAVE_ARCH_TRACEHOOK
126	bool
127
128config HAVE_DMA_ATTRS
129	bool
130
131config USE_GENERIC_SMP_HELPERS
132	bool
133
134config HAVE_REGS_AND_STACK_ACCESS_API
135	bool
136	help
137	  This symbol should be selected by an architecure if it supports
138	  the API needed to access registers and stack entries from pt_regs,
139	  declared in asm/ptrace.h
140	  For example the kprobes-based event tracer needs this API.
141
142config HAVE_CLK
143	bool
144	help
145	  The <linux/clk.h> calls support software clock gating and
146	  thus are a key power management tool on many systems.
147
148config HAVE_DMA_API_DEBUG
149	bool
150
151config HAVE_HW_BREAKPOINT
152	bool
153	depends on PERF_EVENTS
154
155config HAVE_MIXED_BREAKPOINTS_REGS
156	bool
157	depends on HAVE_HW_BREAKPOINT
158	help
159	  Depending on the arch implementation of hardware breakpoints,
160	  some of them have separate registers for data and instruction
161	  breakpoints addresses, others have mixed registers to store
162	  them but define the access type in a control register.
163	  Select this option if your arch implements breakpoints under the
164	  latter fashion.
165
166config HAVE_USER_RETURN_NOTIFIER
167	bool
168
169config HAVE_PERF_EVENTS_NMI
170	bool
171	help
172	  System hardware can generate an NMI using the perf event
173	  subsystem.  Also has support for calculating CPU cycle events
174	  to determine how many clock cycles in a given period.
175
176config HAVE_ARCH_JUMP_LABEL
177	bool
178
179config HAVE_ARCH_MUTEX_CPU_RELAX
180	bool
181
182config HAVE_RCU_TABLE_FREE
183	bool
184
185config ARCH_HAVE_NMI_SAFE_CMPXCHG
186	bool
187
188config HAVE_ALIGNED_STRUCT_PAGE
189	bool
190	help
191	  This makes sure that struct pages are double word aligned and that
192	  e.g. the SLUB allocator can perform double word atomic operations
193	  on a struct page for better performance. However selecting this
194	  might increase the size of a struct page by a word.
195
196config HAVE_CMPXCHG_LOCAL
197	bool
198
199config HAVE_CMPXCHG_DOUBLE
200	bool
201
202source "kernel/gcov/Kconfig"
203