linux-stable-rt/arch/Kconfig

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Create arch/Kconfig Puts the content of arch/Kconfig in the "General setup" menu. Linus: > Should it come with a re-duplication of it's content into each > architecture, which was the case previously ? The oprofile and kprobes > menu entries were litteraly cut and pasted from one architecture to > another. Should we put its content in init/Kconfig then ? I don't think it's a good idea to go back to making it per-architecture, although that extensive "depends on <list-of-archiectures-here>" might indicate that there certainly is room for cleanup there. And I don't think it's wrong keeping it in kernel/Kconfig.xyz per se, I just think it's wrong to (a) lump the code together when it really doesn't necessarily need to and (b) show it to users as some kind of choice that is tied together (whether it then has common code or not). On the per-architecture side, I do think it would be better to *not* have internal architecture knowledge in a generic file, and as such a line like depends on X86_32 || IA64 || PPC || S390 || SPARC64 || X86_64 || AVR32 really shouldn't exist in a file like kernel/Kconfig.instrumentation. It would be much better to do depends on ARCH_SUPPORTS_KPROBES in that generic file, and then architectures that do support it would just have a bool ARCH_SUPPORTS_KPROBES default y in *their* architecture files. That would seem to be much more logical, and is readable both for arch maintainers *and* for people who have no clue - and don't care - about which architecture is supposed to support which interface... Sam Ravnborg: Stuff it into a new file: arch/Kconfig We can then extend this file to include all the 'trailing' Kconfig things that are anyway equal for all ARCHs. But it should be kept clean - so if we introduce such a file then we should use ARCH_HAS_whatever in the arch specific Kconfig files to enable stuff that is not shared. [...] The above suggestion is actually not exactly the best way to do it... First the naming.. A quick grep shows following usage today (in Kconfig files) ARCH_HAS 51 ARCH_SUPPORTS 4 HAVE_ARCH 7 ARCH_HAS is the clear winner. In the common Kconfig file do: config FOO depends on ARCH_HAS_FOO bool "bla bla" config ARCH_HAS_FOO def_bool n In the arch specific Kconfig file in a suitable place do: config SUITABLE_OPTION select ARCH_HAS_FOO The naming of ARCH_HAS_ is fixed and shall be: ARCH_HAS_<config option it will enable> Only a single line added pr. architecture. And we will end up with a (maybe even commented) list of trivial selects. - Yet another update : Moving to HAVE_* now. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-03 04:10:33 +08:00
#
# General architecture dependent options
#
config OPROFILE
tristate "OProfile system profiling (EXPERIMENTAL)"
depends on PROFILING
depends on HAVE_OPROFILE
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_IBS
bool "OProfile AMD IBS support (EXPERIMENTAL)"
default n
depends on OPROFILE && SMP && X86
help
Instruction-Based Sampling (IBS) is a new profiling
technique that provides rich, precise program performance
information. IBS is introduced by AMD Family10h processors
(AMD Opteron Quad-Core processor “Barcelona”) to overcome
the limitations of conventional performance counter
sampling.
If unsure, say N.
config HAVE_OPROFILE
def_bool n
config KPROBES
bool "Kprobes"
depends on KALLSYMS && MODULES
depends on HAVE_KPROBES
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 HAVE_EFFICIENT_UNALIGNED_ACCESS
def_bool n
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 KRETPROBES
def_bool y
depends on KPROBES && HAVE_KRETPROBES
config HAVE_IOREMAP_PROT
def_bool n
config HAVE_KPROBES
def_bool n
config HAVE_KRETPROBES
def_bool n
#
# 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
# arch_ptrace() and not #define __ARCH_SYS_PTRACE
# compat_arch_ptrace() and #define __ARCH_WANT_COMPAT_SYS_PTRACE
# 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
def_bool n
config HAVE_DMA_ATTRS
def_bool n
config USE_GENERIC_SMP_HELPERS
def_bool n
config HAVE_CLK
def_bool n
help
The <linux/clk.h> calls support software clock gating and
thus are a key power management tool on many systems.