Kconfig 6.5 KB
Newer Older
M
Mathieu Desnoyers 已提交
1 2 3
#
# General architecture dependent options
#
4 5

config OPROFILE
6
	tristate "OProfile system profiling"
7 8
	depends on PROFILING
	depends on HAVE_OPROFILE
I
Ingo Molnar 已提交
9
	select RING_BUFFER
10
	select RING_BUFFER_ALLOW_SWAP
11 12 13 14 15 16 17
	help
	  OProfile is a profiling system capable of profiling the
	  whole system, include the kernel, kernel modules, libraries,
	  and applications.

	  If unsure, say N.

18 19 20 21 22 23 24 25 26 27 28 29
config OPROFILE_EVENT_MULTIPLEX
	bool "OProfile multiplexing support (EXPERIMENTAL)"
	default n
	depends on OPROFILE && X86
	help
	  The number of hardware counters is limited. The multiplexing
	  feature enables OProfile to gather more events than counters
	  are provided by the hardware. This is realized by switching
	  between events at an user specified time interval.

	  If unsure, say N.

30
config HAVE_OPROFILE
31
	bool
32

33 34 35 36
config OPROFILE_NMI_TIMER
	def_bool y
	depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI

37 38
config KPROBES
	bool "Kprobes"
39
	depends on MODULES
40
	depends on HAVE_KPROBES
41
	select KALLSYMS
42 43 44 45 46 47 48
	help
	  Kprobes allows you to trap at almost any kernel address and
	  execute a callback function.  register_kprobe() establishes
	  a probepoint and specifies the callback.  Kprobes is useful
	  for kernel debugging, non-intrusive instrumentation and testing.
	  If in doubt, say "N".

49
config JUMP_LABEL
50
       bool "Optimize very unlikely/likely branches"
51 52
       depends on HAVE_ARCH_JUMP_LABEL
       help
53 54 55 56 57 58 59 60
         This option enables a transparent branch optimization that
	 makes certain almost-always-true or almost-always-false branch
	 conditions even cheaper to execute within the kernel.

	 Certain performance-sensitive kernel code, such as trace points,
	 scheduler functionality, networking code and KVM have such
	 branches and include support for this optimization technique.

61
         If it is detected that the compiler has support for "asm goto",
62 63 64 65
	 the kernel will compile such branches with just a nop
	 instruction. When the condition flag is toggled to true, the
	 nop will be converted to a jump instruction to execute the
	 conditional block of instructions.
66

67 68 69
	 This technique lowers overhead and stress on the branch prediction
	 of the processor and generally makes the kernel faster. The update
	 of the condition is slower, but those are always very rare.
70

71 72
	 ( On 32-bit x86, the necessary options added to the compiler
	   flags may increase the size of the kernel slightly. )
73

74
config OPTPROBES
75 76
	def_bool y
	depends on KPROBES && HAVE_OPTPROBES
77 78
	depends on !PREEMPT

79
config UPROBES
80
	bool "Transparent user-space probes (EXPERIMENTAL)"
81
	depends on UPROBE_EVENTS && PERF_EVENTS
82 83
	default n
	help
84 85 86 87 88 89 90 91 92
	  Uprobes is the user-space counterpart to kprobes: they
	  enable instrumentation applications (such as 'perf probe')
	  to establish unintrusive probes in user-space binaries and
	  libraries, by executing handler functions when the probes
	  are hit by user-space applications.

	  ( These probes come in the form of single-byte breakpoints,
	    managed by the kernel and kept transparent to the probed
	    application. )
93 94 95

	  If in doubt, say "N".

96
config HAVE_EFFICIENT_UNALIGNED_ACCESS
97
	bool
98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114
	help
	  Some architectures are unable to perform unaligned accesses
	  without the use of get_unaligned/put_unaligned. Others are
	  unable to perform such accesses efficiently (e.g. trap on
	  unaligned access and require fixing it up in the exception
	  handler.)

	  This symbol should be selected by an architecture if it can
	  perform unaligned accesses efficiently to allow different
	  code paths to be selected for these cases. Some network
	  drivers, for example, could opt to not fix up alignment
	  problems with received packets if doing so would not help
	  much.

	  See Documentation/unaligned-memory-access.txt for more
	  information on the topic of unaligned memory accesses.

115 116 117
config HAVE_SYSCALL_WRAPPERS
	bool

118 119 120 121
config KRETPROBES
	def_bool y
	depends on KPROBES && HAVE_KRETPROBES

A
Avi Kivity 已提交
122 123 124 125 126 127 128
config USER_RETURN_NOTIFIER
	bool
	depends on HAVE_USER_RETURN_NOTIFIER
	help
	  Provide a kernel-internal notification when a cpu is about to
	  switch to user mode.

129
config HAVE_IOREMAP_PROT
130
	bool
131

132
config HAVE_KPROBES
133
	bool
134 135

config HAVE_KRETPROBES
136
	bool
137

138 139
config HAVE_OPTPROBES
	bool
140 141 142

config HAVE_NMI_WATCHDOG
	bool
143 144 145 146 147 148 149 150 151 152 153 154 155 156
#
# An arch should select this if it provides all these things:
#
#	task_pt_regs()		in asm/processor.h or asm/ptrace.h
#	arch_has_single_step()	if there is hardware single-step support
#	arch_has_block_step()	if there is hardware block-step support
#	asm/syscall.h		supplying asm-generic/syscall.h interface
#	linux/regset.h		user_regset interfaces
#	CORE_DUMP_USE_REGSET	#define'd in linux/elf.h
#	TIF_SYSCALL_TRACE	calls tracehook_report_syscall_{entry,exit}
#	TIF_NOTIFY_RESUME	calls tracehook_notify_resume()
#	signal delivery		calls tracehook_signal_handler()
#
config HAVE_ARCH_TRACEHOOK
157
	bool
158

159
config HAVE_DMA_ATTRS
160
	bool
161 162

config USE_GENERIC_SMP_HELPERS
163
	bool
164

165 166
config HAVE_REGS_AND_STACK_ACCESS_API
	bool
167 168 169 170 171
	help
	  This symbol should be selected by an architecure if it supports
	  the API needed to access registers and stack entries from pt_regs,
	  declared in asm/ptrace.h
	  For example the kprobes-based event tracer needs this API.
172

173
config HAVE_CLK
174
	bool
175 176 177 178
	help
	  The <linux/clk.h> calls support software clock gating and
	  thus are a key power management tool on many systems.

J
Joerg Roedel 已提交
179 180
config HAVE_DMA_API_DEBUG
	bool
181

182 183
config HAVE_HW_BREAKPOINT
	bool
184
	depends on PERF_EVENTS
185

186 187 188 189 190 191 192 193 194 195 196
config HAVE_MIXED_BREAKPOINTS_REGS
	bool
	depends on HAVE_HW_BREAKPOINT
	help
	  Depending on the arch implementation of hardware breakpoints,
	  some of them have separate registers for data and instruction
	  breakpoints addresses, others have mixed registers to store
	  them but define the access type in a control register.
	  Select this option if your arch implements breakpoints under the
	  latter fashion.

A
Avi Kivity 已提交
197 198
config HAVE_USER_RETURN_NOTIFIER
	bool
199

200 201
config HAVE_PERF_EVENTS_NMI
	bool
202 203 204 205
	help
	  System hardware can generate an NMI using the perf event
	  subsystem.  Also has support for calculating CPU cycle events
	  to determine how many clock cycles in a given period.
206

207 208 209
config HAVE_ARCH_JUMP_LABEL
	bool

210 211 212
config HAVE_ARCH_MUTEX_CPU_RELAX
	bool

213 214 215
config HAVE_RCU_TABLE_FREE
	bool

216 217 218
config ARCH_HAVE_NMI_SAFE_CMPXCHG
	bool

219 220 221 222 223 224 225 226
config HAVE_ALIGNED_STRUCT_PAGE
	bool
	help
	  This makes sure that struct pages are double word aligned and that
	  e.g. the SLUB allocator can perform double word atomic operations
	  on a struct page for better performance. However selecting this
	  might increase the size of a struct page by a word.

227 228 229
config HAVE_CMPXCHG_LOCAL
	bool

230 231 232
config HAVE_CMPXCHG_DOUBLE
	bool

233 234 235
config ARCH_WANT_OLD_COMPAT_IPC
	bool

236
source "kernel/gcov/Kconfig"