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author | Paul E. McKenney <paulmck@kernel.org> | 2022-03-17 11:05:09 -0700 |
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committer | Paul E. McKenney <paulmck@kernel.org> | 2022-04-20 16:52:58 -0700 |
commit | 835f14ed53076384f0e1dad2fddb4881315f124f (patch) | |
tree | 3bea30a7de871d8b9979c2c90ff6b587dc613a47 | |
parent | 46e861be589881e0905b9ade3d8439883858721c (diff) | |
download | linux-835f14ed53076384f0e1dad2fddb4881315f124f.tar.bz2 |
rcu: Make the TASKS_RCU Kconfig option be selected
Currently, any kernel built with CONFIG_PREEMPTION=y also gets
CONFIG_TASKS_RCU=y, which is not helpful to people trying to build
preemptible kernels of minimal size.
Because CONFIG_TASKS_RCU=y is needed only in kernels doing tracing of
one form or another, this commit moves from TASKS_RCU deciding when it
should be enabled to the tracing Kconfig options explicitly selecting it.
This allows building preemptible kernels without TASKS_RCU, if desired.
This commit also updates the SRCU-N and TREE09 rcutorture scenarios
in order to avoid Kconfig errors that would otherwise result from
CONFIG_TASKS_RCU being selected without its CONFIG_RCU_EXPERT dependency
being met.
[ paulmck: Apply BPF_SYSCALL feedback from Andrii Nakryiko. ]
Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
-rw-r--r-- | arch/Kconfig | 1 | ||||
-rw-r--r-- | kernel/bpf/Kconfig | 1 | ||||
-rw-r--r-- | kernel/rcu/Kconfig | 3 | ||||
-rw-r--r-- | kernel/trace/Kconfig | 1 | ||||
-rw-r--r-- | tools/testing/selftests/rcutorture/configs/rcu/SRCU-N | 2 | ||||
-rw-r--r-- | tools/testing/selftests/rcutorture/configs/rcu/TREE09 | 2 |
6 files changed, 9 insertions, 1 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 29b0167c088b..1bf29ce754af 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -35,6 +35,7 @@ config KPROBES depends on MODULES depends on HAVE_KPROBES select KALLSYMS + select TASKS_RCU if PREEMPTION help Kprobes allows you to trap at almost any kernel address and execute a callback function. register_kprobe() establishes diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index d56ee177d5f8..2dfe1079f772 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -27,6 +27,7 @@ config BPF_SYSCALL bool "Enable bpf() system call" select BPF select IRQ_WORK + select TASKS_RCU if PREEMPTION select TASKS_TRACE_RCU select BINARY_PRINTF select NET_SOCK_MSG if NET diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index f559870fbf8b..4f665ae0cf55 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -78,7 +78,8 @@ config TASKS_RCU_GENERIC task-based RCU implementations. Not for manual selection. config TASKS_RCU - def_bool PREEMPTION + def_bool 0 + select IRQ_WORK help This option enables a task-based RCU implementation that uses only voluntary context switch (not preemption!), idle, and diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 2c43e327a619..bf5da6c4e999 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -144,6 +144,7 @@ config TRACING select BINARY_PRINTF select EVENT_TRACING select TRACE_CLOCK + select TASKS_RCU if PREEMPTION config GENERIC_TRACER bool diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N index 2da8b49589a0..07f5e0a70ae7 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N @@ -6,3 +6,5 @@ CONFIG_PREEMPT_NONE=y CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=n #CHECK#CONFIG_RCU_EXPERT=n +CONFIG_KPROBES=n +CONFIG_FTRACE=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 index 8523a7515cbf..fc45645bb5f4 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 @@ -13,3 +13,5 @@ CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n #CHECK#CONFIG_RCU_EXPERT=n +CONFIG_KPROBES=n +CONFIG_FTRACE=n |