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kernel: disable CONFIG_RCU_EXPERT and friends

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Based on the existing documentation [1][2], I dare anyone to demonstrate that
we need to fine-tune these RCU parameters. The (performance) breakage potential
for doing so is immense, so let's just please put down this loaded footgun.

Disable CONFIG_RCU_EXPERT and its dependent symbols. Additionally, remove the
CONFIG_RCU_EXPERT symbol from the target kconfigs which contain it.

[1] https://www.kernel.org/doc/Documentation/RCU/Design/Data-Structures/Data-Structures.html
[2] https://lwn.net/Articles/777214/

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
This commit is contained in:
Rui Salvaterra
2021-08-22 14:50:07 +01:00
committed by Hauke Mehrtens
parent b8f8d0651c
commit 7e135add24
14 changed files with 2 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
target/linux/generic/config-5.10
View File

@@ -4631,12 +4631,8 @@ CONFIG_PWRSEQ_SIMPLE=y
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_EQS_DEBUG is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
CONFIG_RCU_EXPERT=y
CONFIG_RCU_FANOUT=32
CONFIG_RCU_FANOUT_LEAF=16
# CONFIG_RCU_FAST_NO_HZ is not set
# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_KTHREAD_PRIO=0
# CONFIG_RCU_NOCB_CPU is not set
# CONFIG_RCU_PERF_TEST is not set
# CONFIG_RCU_REF_SCALE_TEST is not set
# CONFIG_RCU_SCALE_TEST is not set
@@ -5995,7 +5991,6 @@ CONFIG_SYSVIPC_SYSCTL=y
# CONFIG_TARGET_CORE is not set
# CONFIG_TASKSTATS is not set
# CONFIG_TASKS_RCU is not set
CONFIG_TASKS_TRACE_RCU_READ_MB=y
# CONFIG_TASK_XACCT is not set
# CONFIG_TC35815 is not set
# CONFIG_TCG_ATMEL is not set

6
target/linux/generic/config-5.4
View File

@@ -4262,12 +4262,8 @@ CONFIG_PWRSEQ_SIMPLE=y
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_EQS_DEBUG is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
CONFIG_RCU_EXPERT=y
CONFIG_RCU_FANOUT=32
CONFIG_RCU_FANOUT_LEAF=16
# CONFIG_RCU_FAST_NO_HZ is not set
# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_KTHREAD_PRIO=0
# CONFIG_RCU_NOCB_CPU is not set
# CONFIG_RCU_PERF_TEST is not set
# CONFIG_RCU_TORTURE_TEST is not set
CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY=3