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| author |   Paul E. McKenney <paulmck@kernel.org> | 2021-09-27 14:18:51 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-11-30 17:24:47 -0800 |
| commit | e2c73a6860bdf54f2c6bf8cddc34ddc91a1343e1 (patch) | |
| tree | d8b4e1ad9c9a7131bfe6fe50235e4d66465364cc /tools | |
| parent | torture: Remove RCU_FAST_NO_HZ from rcu scenarios (diff) | |
| download | linux-dev-e2c73a6860bdf54f2c6bf8cddc34ddc91a1343e1.tar.xz linux-dev-e2c73a6860bdf54f2c6bf8cddc34ddc91a1343e1.zip | |
rcu: Remove the RCU_FAST_NO_HZ Kconfig option
All of the uses of CONFIG_RCU_FAST_NO_HZ=y that I have seen involve
systems with RCU callbacks offloaded. In this situation, all that this
Kconfig option does is slow down idle entry/exit with an additional
allways-taken early exit. If this is the only use case, then this
Kconfig option nothing but an attractive nuisance that needs to go away.
This commit therefore removes the RCU_FAST_NO_HZ Kconfig option.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'tools')
3 files changed, 0 insertions, 3 deletions
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 index b5b53973c01e..8ae41d5f81a3 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 @@ -6,7 +6,6 @@ CONFIG_PREEMPT=y CONFIG_HZ_PERIODIC=n CONFIG_NO_HZ_IDLE=y CONFIG_NO_HZ_FULL=n -CONFIG_RCU_FAST_NO_HZ=y CONFIG_RCU_TRACE=y CONFIG_HOTPLUG_CPU=y CONFIG_MAXSMP=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 index f6d6a40c0576..22ad0261728d 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 @@ -7,7 +7,6 @@ CONFIG_PREEMPT=n CONFIG_HZ_PERIODIC=n CONFIG_NO_HZ_IDLE=n CONFIG_NO_HZ_FULL=y -CONFIG_RCU_FAST_NO_HZ=y CONFIG_RCU_TRACE=y CONFIG_RCU_FANOUT=4 CONFIG_RCU_FANOUT_LEAF=3 diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt index 1b96d68473b8..42acb1a64ce1 100644 --- a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt +++ b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt @@ -15,7 +15,6 @@ CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING. CONFIG_RCU_BOOST -- one of PREEMPT_RCU. CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others. CONFIG_RCU_FANOUT_LEAF -- Do one non-default. -CONFIG_RCU_FAST_NO_HZ -- Do one, but not with all nohz_full CPUs. CONFIG_RCU_NOCB_CPU -- Do three, one with no rcu_nocbs CPUs, one with rcu_nocbs=0, and one with all rcu_nocbs CPUs. CONFIG_RCU_TRACE -- Do half. |