diff options
Diffstat (limited to 'init/Kconfig')
| -rw-r--r-- | init/Kconfig | 85 |
1 files changed, 61 insertions, 24 deletions
diff --git a/init/Kconfig b/init/Kconfig index 2d9b83104dcf..54d3fa5ae723 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -53,6 +53,20 @@ config CROSS_COMPILE need to set this unless you want the configured kernel build directory to select the cross-compiler automatically. +config COMPILE_TEST + bool "Compile also drivers which will not load" + default n + help + Some drivers can be compiled on a different platform than they are + intended to be run on. Despite they cannot be loaded there (or even + when they load they cannot be used due to missing HW support), + developers still, opposing to distributors, might want to build such + drivers to compile-test them. + + If you are a developer and want to build everything available, say Y + here. If you are a user/distributor, say N here to exclude useless + drivers to be distributed. + config LOCALVERSION string "Local version - append to kernel release" help @@ -98,10 +112,13 @@ config HAVE_KERNEL_XZ config HAVE_KERNEL_LZO bool +config HAVE_KERNEL_LZ4 + bool + choice prompt "Kernel compression mode" default KERNEL_GZIP - depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO + depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 help The linux kernel is a kind of self-extracting executable. Several compression algorithms are available, which differ @@ -168,6 +185,18 @@ config KERNEL_LZO size is about 10% bigger than gzip; however its speed (both compression and decompression) is the fastest. +config KERNEL_LZ4 + bool "LZ4" + depends on HAVE_KERNEL_LZ4 + help + LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding. + A preliminary version of LZ4 de/compression tool is available at + <https://code.google.com/p/lz4/>. + + Its compression ratio is worse than LZO. The size of the kernel + is about 8% bigger than LZO. But the decompression speed is + faster than LZO. + endchoice config DEFAULT_HOSTNAME @@ -459,18 +488,10 @@ config TINY_RCU is not required. This option greatly reduces the memory footprint of RCU. -config TINY_PREEMPT_RCU - bool "Preemptible UP-only small-memory-footprint RCU" - depends on PREEMPT && !SMP - help - This option selects the RCU implementation that is designed - for real-time UP systems. This option greatly reduces the - memory footprint of RCU. - endchoice config PREEMPT_RCU - def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU ) + def_bool TREE_PREEMPT_RCU help This option enables preemptible-RCU code that is common between the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. @@ -656,7 +677,7 @@ config RCU_BOOST_DELAY Accept the default if unsure. config RCU_NOCB_CPU - bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL" + bool "Offload RCU callback processing from boot-selected CPUs" depends on TREE_RCU || TREE_PREEMPT_RCU default n help @@ -682,9 +703,10 @@ choice prompt "Build-forced no-CBs CPUs" default RCU_NOCB_CPU_NONE help - This option allows no-CBs CPUs to be specified at build time. - Additional no-CBs CPUs may be specified by the rcu_nocbs= - boot parameter. + This option allows no-CBs CPUs (whose RCU callbacks are invoked + from kthreads rather than from softirq context) to be specified + at build time. Additional no-CBs CPUs may be specified by + the rcu_nocbs= boot parameter. config RCU_NOCB_CPU_NONE bool "No build_forced no-CBs CPUs" @@ -692,25 +714,40 @@ config RCU_NOCB_CPU_NONE help This option does not force any of the CPUs to be no-CBs CPUs. Only CPUs designated by the rcu_nocbs= boot parameter will be - no-CBs CPUs. + no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU + kthreads whose names begin with "rcuo". All other CPUs will + invoke their own RCU callbacks in softirq context. + + Select this option if you want to choose no-CBs CPUs at + boot time, for example, to allow testing of different no-CBs + configurations without having to rebuild the kernel each time. config RCU_NOCB_CPU_ZERO bool "CPU 0 is a build_forced no-CBs CPU" depends on RCU_NOCB_CPU && !NO_HZ_FULL help - This option forces CPU 0 to be a no-CBs CPU. Additional CPUs - may be designated as no-CBs CPUs using the rcu_nocbs= boot - parameter will be no-CBs CPUs. + This option forces CPU 0 to be a no-CBs CPU, so that its RCU + callbacks are invoked by a per-CPU kthread whose name begins + with "rcuo". Additional CPUs may be designated as no-CBs + CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs. + All other CPUs will invoke their own RCU callbacks in softirq + context. Select this if CPU 0 needs to be a no-CBs CPU for real-time - or energy-efficiency reasons. + or energy-efficiency reasons, but the real reason it exists + is to ensure that randconfig testing covers mixed systems. config RCU_NOCB_CPU_ALL bool "All CPUs are build_forced no-CBs CPUs" depends on RCU_NOCB_CPU help This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs= - boot parameter will be ignored. + boot parameter will be ignored. All CPUs' RCU callbacks will + be executed in the context of per-CPU rcuo kthreads created for + this purpose. Assuming that the kthreads whose names start with + "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter + on the remaining CPUs, but might decrease memory locality during + RCU-callback invocation, thus potentially degrading throughput. Select this if all CPUs need to be no-CBs CPUs for real-time or energy-efficiency reasons. @@ -758,6 +795,9 @@ config LOG_BUF_SHIFT config HAVE_UNSTABLE_SCHED_CLOCK bool +config GENERIC_SCHED_CLOCK + bool + # # For architectures that want to enable the support for NUMA-affine scheduler # balancing logic: @@ -877,7 +917,7 @@ config MEMCG Note that setting this option increases fixed memory overhead associated with each page of memory in the system. By this, - 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory + 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory usage tracking struct at boot. Total amount of this is printed out at boot. @@ -1245,9 +1285,6 @@ config SYSCTL_ARCH_UNALIGN_ALLOW the unaligned access emulation. see arch/parisc/kernel/unaligned.c for reference -config HOTPLUG - def_bool y - config HAVE_PCSPKR_PLATFORM bool |