## General architecture dependent options# config OPROFILE	tristate "OProfile system profiling"	depends on PROFILING	depends on HAVE_OPROFILE	select RING_BUFFER	select RING_BUFFER_ALLOW_SWAP	help	  OProfile is a profiling system capable of profiling the	  whole system, include the kernel, kernel modules, libraries,	  and applications. 	  If unsure, say N. 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. config HAVE_OPROFILE	bool config OPROFILE_NMI_TIMER	def_bool y	depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI config KPROBES	bool "Kprobes"	depends on MODULES	depends on HAVE_KPROBES	select KALLSYMS	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". config JUMP_LABEL       bool "Optimize very unlikely/likely branches"       depends on HAVE_ARCH_JUMP_LABEL       help         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.          If it is detected that the compiler has support for "asm goto",	 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. 	 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. 	 ( On 32-bit x86, the necessary options added to the compiler	   flags may increase the size of the kernel slightly. ) config OPTPROBES	def_bool y	depends on KPROBES && HAVE_OPTPROBES	depends on !PREEMPT config UPROBES	bool "Transparent user-space probes (EXPERIMENTAL)"	depends on UPROBE_EVENT && PERF_EVENTS	default n	help	  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. ) 	  If in doubt, say "N". config HAVE_EFFICIENT_UNALIGNED_ACCESS	bool	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. config HAVE_SYSCALL_WRAPPERS	bool config KRETPROBES	def_bool y	depends on KPROBES && HAVE_KRETPROBES 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. config HAVE_IOREMAP_PROT	bool config HAVE_KPROBES	bool config HAVE_KRETPROBES	bool config HAVE_OPTPROBES	bool config HAVE_NMI_WATCHDOG	bool## 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	bool config HAVE_DMA_ATTRS	bool config HAVE_DMA_CONTIGUOUS	bool config USE_GENERIC_SMP_HELPERS	bool config GENERIC_SMP_IDLE_THREAD       bool # Select if arch init_task initializer is different to init/init_task.cconfig ARCH_INIT_TASK       bool # Select if arch has its private alloc_task_struct() functionconfig ARCH_TASK_STRUCT_ALLOCATOR	bool # Select if arch has its private alloc_thread_info() functionconfig ARCH_THREAD_INFO_ALLOCATOR	bool config HAVE_REGS_AND_STACK_ACCESS_API	bool	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. config HAVE_CLK	bool	help	  The <linux/clk.h> calls support software clock gating and	  thus are a key power management tool on many systems. config HAVE_DMA_API_DEBUG	bool config HAVE_HW_BREAKPOINT	bool	depends on PERF_EVENTS 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. config HAVE_USER_RETURN_NOTIFIER	bool config HAVE_PERF_EVENTS_NMI	bool	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. config HAVE_ARCH_JUMP_LABEL	bool config HAVE_ARCH_MUTEX_CPU_RELAX	bool config HAVE_RCU_TABLE_FREE	bool config ARCH_HAVE_NMI_SAFE_CMPXCHG	bool 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. config HAVE_CMPXCHG_LOCAL	bool config HAVE_CMPXCHG_DOUBLE	bool config ARCH_WANT_OLD_COMPAT_IPC	bool config HAVE_ARCH_SECCOMP_FILTER	bool	help	  An arch should select this symbol if it provides all of these things:	  - syscall_get_arch()	  - syscall_get_arguments()	  - syscall_rollback()	  - syscall_set_return_value()	  - SIGSYS siginfo_t support	  - secure_computing is called from a ptrace_event()-safe context	  - secure_computing return value is checked and a return value of -1	    results in the system call being skipped immediately. config SECCOMP_FILTER	def_bool y	depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET	help	  Enable tasks to build secure computing environments defined	  in terms of Berkeley Packet Filter programs which implement	  task-defined system call filtering polices. 	  See Documentation/prctl/seccomp_filter.txt for details. source "kernel/gcov/Kconfig"