# Kind of a stub config for the pure tick based cputime accounting
config TICK_CPU_ACCOUNTING
bool "Simple tick based cputime accounting"
- depends on !S390
+ depends on !S390 && !NO_HZ_FULL
help
This is the basic tick based cputime accounting that maintains
statistics about user, system and idle time spent on per jiffies
config VIRT_CPU_ACCOUNTING_NATIVE
bool "Deterministic task and CPU time accounting"
- depends on HAVE_VIRT_CPU_ACCOUNTING
+ depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
select VIRT_CPU_ACCOUNTING
help
Select this option to enable more accurate task and CPU time
config IRQ_TIME_ACCOUNTING
bool "Fine granularity task level IRQ time accounting"
- depends on HAVE_IRQ_TIME_ACCOUNTING
+ depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
help
Select this option to enable fine granularity task irq time
accounting. This is done by reading a timestamp on each
config TREE_RCU
bool "Tree-based hierarchical RCU"
depends on !PREEMPT && SMP
+ select IRQ_WORK
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
config CONTEXT_TRACKING_FORCE
bool "Force context tracking"
depends on CONTEXT_TRACKING
+ default CONTEXT_TRACKING
help
Probe on user/kernel boundaries by default in order to
test the features that rely on it such as userspace RCU extended
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on NO_HZ && SMP
+ depends on NO_HZ_COMMON && SMP
default n
help
- This option causes RCU to attempt to accelerate grace periods in
- order to allow CPUs to enter dynticks-idle state more quickly.
- On the other hand, this option increases the overhead of the
- dynticks-idle checking, thus degrading scheduling latency.
+ This option permits CPUs to enter dynticks-idle state even if
+ they have RCU callbacks queued, and prevents RCU from waking
+ these CPUs up more than roughly once every four jiffies (by
+ default, you can adjust this using the rcutree.rcu_idle_gp_delay
+ parameter), thus improving energy efficiency. On the other
+ hand, this option increases the duration of RCU grace periods,
+ for example, slowing down synchronize_rcu().
- Say Y if energy efficiency is critically important, and you don't
- care about real-time response.
+ Say Y if energy efficiency is critically important, and you
+ don't care about increased grace-period durations.
Say N if you are unsure.
Accept the default if unsure.
config RCU_NOCB_CPU
- bool "Offload RCU callback processing from boot-selected CPUs"
+ bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
depends on TREE_RCU || TREE_PREEMPT_RCU
default n
help
This option offloads callback invocation from the set of
CPUs specified at boot time by the rcu_nocbs parameter.
- For each such CPU, a kthread ("rcuoN") will be created to
- invoke callbacks, where the "N" is the CPU being offloaded.
- Nothing prevents this kthread from running on the specified
- CPUs, but (1) the kthreads may be preempted between each
- callback, and (2) affinity or cgroups can be used to force
- the kthreads to run on whatever set of CPUs is desired.
-
- Say Y here if you want reduced OS jitter on selected CPUs.
+ For each such CPU, a kthread ("rcuox/N") will be created to
+ invoke callbacks, where the "N" is the CPU being offloaded,
+ and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
+ "s" for RCU-sched. Nothing prevents this kthread from running
+ on the specified CPUs, but (1) the kthreads may be preempted
+ between each callback, and (2) affinity or cgroups can be used
+ to force the kthreads to run on whatever set of CPUs is desired.
+
+ Say Y here if you want to help to debug reduced OS jitter.
Say N here if you are unsure.
+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.
+
+config RCU_NOCB_CPU_NONE
+ bool "No build_forced no-CBs CPUs"
+ depends on RCU_NOCB_CPU && !NO_HZ_FULL
+ 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.
+
+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.
+
+ Select this if CPU 0 needs to be a no-CBs CPU for real-time
+ or energy-efficiency reasons.
+
+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.
+
+ Select this if all CPUs need to be no-CBs CPUs for real-time
+ or energy-efficiency reasons.
+
+endchoice
+
endmenu # "RCU Subsystem"
config IKCONFIG
config ANON_INODES
bool
+config HAVE_UID16
+ bool
+
+config SYSCTL_EXCEPTION_TRACE
+ bool
+ help
+ Enable support for /proc/sys/debug/exception-trace.
+
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+ bool
+ help
+ Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+ Allows arch to define/use @no_unaligned_warning to possibly warn
+ about unaligned access emulation going on under the hood.
+
+config SYSCTL_ARCH_UNALIGN_ALLOW
+ bool
+ help
+ Enable support for /proc/sys/kernel/unaligned-trap
+ Allows arches to define/use @unaligned_enabled to runtime toggle
+ the unaligned access emulation.
+ see arch/parisc/kernel/unaligned.c for reference
+
+config HOTPLUG
+ def_bool y
+
+config HAVE_PCSPKR_PLATFORM
+ bool
+
menuconfig EXPERT
bool "Configure standard kernel features (expert users)"
# Unhide debug options, to make the on-by-default options visible
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.
-config HAVE_UID16
- bool
-
config UID16
bool "Enable 16-bit UID system calls" if EXPERT
depends on HAVE_UID16
If unsure say N here.
-config SYSCTL_EXCEPTION_TRACE
- bool
- help
- Enable support for /proc/sys/debug/exception-trace.
-
-config SYSCTL_ARCH_UNALIGN_NO_WARN
- bool
- help
- Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
- Allows arch to define/use @no_unaligned_warning to possibly warn
- about unaligned access emulation going on under the hood.
-
-config SYSCTL_ARCH_UNALIGN_ALLOW
- bool
- help
- Enable support for /proc/sys/kernel/unaligned-trap
- Allows arches to define/use @unaligned_enabled to runtime toggle
- the unaligned access emulation.
- see arch/parisc/kernel/unaligned.c for reference
-
config KALLSYMS
bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
Say N unless you really need all symbols.
-config HOTPLUG
- def_bool y
-
config PRINTK
default y
bool "Enable support for printk" if EXPERT
This option allows to disable the internal PC-Speaker
support, saving some memory.
-config HAVE_PCSPKR_PLATFORM
- bool
-
config BASE_FULL
default y
bool "Enable full-sized data structures for core" if EXPERT
default y
help
This option enables POSIX asynchronous I/O which may by used
- by some high performance threaded applications. Disabling
- this option saves about 7k.
+ by some high performance threaded applications. Disabling
+ this option saves about 7k.
+
+config PCI_QUIRKS
+ default y
+ bool "Enable PCI quirk workarounds" if EXPERT
+ depends on PCI
+ help
+ This enables workarounds for various PCI chipset
+ bugs/quirks. Disable this only if your target machine is
+ unaffected by PCI quirks.
config EMBEDDED
bool "Embedded system"
on EXPERT systems. /proc/vmstat will only show page counts
if VM event counters are disabled.
-config PCI_QUIRKS
- default y
- bool "Enable PCI quirk workarounds" if EXPERT
- depends on PCI
- help
- This enables workarounds for various PCI chipset
- bugs/quirks. Disable this only if your target machine is
- unaffected by PCI quirks.
-
config SLUB_DEBUG
default y
bool "Enable SLUB debugging support" if EXPERT
projects / ~andy / linux / blobdiff