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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-03 11:34:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-03 11:34:53 -0700
commit330e9e46253cbfab178450c976aa90ef0f3ae940 (patch)
tree4a9875d264a477449a9c9a0ff23937550d1c3234 /kernel/time
parente94693f797400b9f424c69e1da9381e4846762fe (diff)
parent567b64aaefc4ef9ae3af124ae0b13dc13a6804a8 (diff)
downloadlinux-330e9e46253cbfab178450c976aa90ef0f3ae940.tar.bz2
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar: "The sole purpose of these changes is to shrink and simplify the RCU code base, which has suffered from creeping bloat over the past couple of years. The end result is a net removal of ~2700 lines of code: 79 files changed, 1496 insertions(+), 4211 deletions(-) Plus there's a marked reduction in the Kconfig space complexity as well, here's the number of matches on 'grep RCU' in the .config: before after x86-defconfig 17 15 x86-allmodconfig 33 20" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (86 commits) rcu: Remove RCU CPU stall warnings from Tiny RCU rcu: Remove event tracing from Tiny RCU rcu: Move RCU debug Kconfig options to kernel/rcu rcu: Move RCU non-debug Kconfig options to kernel/rcu rcu: Eliminate NOCBs CPU-state Kconfig options rcu: Remove debugfs tracing srcu: Remove Classic SRCU srcu: Fix rcutorture-statistics typo rcu: Remove SPARSE_RCU_POINTER Kconfig option rcu: Remove the now-obsolete PROVE_RCU_REPEATEDLY Kconfig option rcu: Remove typecheck() from RCU locking wrapper functions rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h rcu: Remove nohz_full full-system-idle state machine rcu: Remove the RCU_KTHREAD_PRIO Kconfig option rcu: Remove *_SLOW_* Kconfig options srcu: Use rnp->lock wrappers to replace explicit memory barriers rcu: Move rnp->lock wrappers for SRCU use rcu: Convert rnp->lock wrappers to macros for SRCU use rcu: Refactor #includes from include/linux/rcupdate.h bcm47xx: Fix build regression ...
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/Kconfig50
1 files changed, 0 insertions, 50 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 4008d9f95dd7..ac09bc29eb08 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -126,56 +126,6 @@ config NO_HZ_FULL_ALL
Note the boot CPU will still be kept outside the range to
handle the timekeeping duty.
-config NO_HZ_FULL_SYSIDLE
- bool "Detect full-system idle state for full dynticks system"
- depends on NO_HZ_FULL
- default n
- help
- At least one CPU must keep the scheduling-clock tick running for
- timekeeping purposes whenever there is a non-idle CPU, where
- "non-idle" also includes dynticks CPUs as long as they are
- running non-idle tasks. Because the underlying adaptive-tick
- support cannot distinguish between all CPUs being idle and
- all CPUs each running a single task in dynticks mode, the
- underlying support simply ensures that there is always a CPU
- handling the scheduling-clock tick, whether or not all CPUs
- are idle. This Kconfig option enables scalable detection of
- the all-CPUs-idle state, thus allowing the scheduling-clock
- tick to be disabled when all CPUs are idle. Note that scalable
- detection of the all-CPUs-idle state means that larger systems
- will be slower to declare the all-CPUs-idle state.
-
- Say Y if you would like to help debug all-CPUs-idle detection.
-
- Say N if you are unsure.
-
-config NO_HZ_FULL_SYSIDLE_SMALL
- int "Number of CPUs above which large-system approach is used"
- depends on NO_HZ_FULL_SYSIDLE
- range 1 NR_CPUS
- default 8
- help
- The full-system idle detection mechanism takes a lazy approach
- on large systems, as is required to attain decent scalability.
- However, on smaller systems, scalability is not anywhere near as
- large a concern as is energy efficiency. The sysidle subsystem
- therefore uses a fast but non-scalable algorithm for small
- systems and a lazier but scalable algorithm for large systems.
- This Kconfig parameter defines the number of CPUs in the largest
- system that will be considered to be "small".
-
- The default value will be fine in most cases. Battery-powered
- systems that (1) enable NO_HZ_FULL_SYSIDLE, (2) have larger
- numbers of CPUs, and (3) are suffering from battery-lifetime
- problems due to long sysidle latencies might wish to experiment
- with larger values for this Kconfig parameter. On the other
- hand, they might be even better served by disabling NO_HZ_FULL
- entirely, given that NO_HZ_FULL is intended for HPC and
- real-time workloads that at present do not tend to be run on
- battery-powered systems.
-
- Take the default if you are unsure.
-
config NO_HZ
bool "Old Idle dynticks config"
depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS