diff options
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 34884faf98c..8e9e3246b2b 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -80,6 +80,7 @@ config UPROBES bool "Transparent user-space probes (EXPERIMENTAL)" depends on UPROBE_EVENT && PERF_EVENTS default n + select PERCPU_RWSEM help Uprobes is the user-space counterpart to kprobes: they enable instrumentation applications (such as 'perf probe') @@ -112,6 +113,25 @@ config HAVE_EFFICIENT_UNALIGNED_ACCESS See Documentation/unaligned-memory-access.txt for more information on the topic of unaligned memory accesses. +config ARCH_USE_BUILTIN_BSWAP + bool + help + Modern versions of GCC (since 4.4) have builtin functions + for handling byte-swapping. Using these, instead of the old + inline assembler that the architecture code provides in the + __arch_bswapXX() macros, allows the compiler to see what's + happening and offers more opportunity for optimisation. In + particular, the compiler will be able to combine the byteswap + with a nearby load or store and use load-and-swap or + store-and-swap instructions if the architecture has them. It + should almost *never* result in code which is worse than the + hand-coded assembler in <asm/swab.h>. But just in case it + does, the use of the builtins is optional. + + Any architecture with load-and-swap or store-and-swap + instructions should set this. And it shouldn't hurt to set it + on architectures that don't have such instructions. + config HAVE_SYSCALL_WRAPPERS bool |