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>
14 files changed:
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_EQS_DEBUG is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
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_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
# CONFIG_RCU_PERF_TEST is not set
# CONFIG_RCU_REF_SCALE_TEST is not set
# CONFIG_RCU_SCALE_TEST is not set
# CONFIG_TARGET_CORE is not set
# CONFIG_TASKSTATS is not set
# CONFIG_TASKS_RCU is not set
# 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
# CONFIG_TASK_XACCT is not set
# CONFIG_TC35815 is not set
# CONFIG_TCG_ATMEL is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_EQS_DEBUG is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
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_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
# CONFIG_RCU_PERF_TEST is not set
# CONFIG_RCU_TORTURE_TEST is not set
CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY=3
# CONFIG_RANDOMIZE_BASE is not set
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
# CONFIG_RANDOMIZE_BASE is not set
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_GZIP=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_GZIP=y
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RD_BZIP2=y
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REGMAP=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REGMAP=y
CONFIG_EXT4_FS=y
CONFIG_FS_MBCACHE=y
CONFIG_MACH_OX810SE=y
CONFIG_EXT4_FS=y
CONFIG_FS_MBCACHE=y
CONFIG_MACH_OX810SE=y
-# CONFIG_RCU_EXPERT is not set
# CONFIG_RCU_NEED_SEGCBLIST is not set
# CONFIG_RCU_STALL_COMMON is not set
# CONFIG_RCU_NEED_SEGCBLIST is not set
# CONFIG_RCU_STALL_COMMON is not set
# CONFIG_PL310_ERRATA_769419 is not set
CONFIG_PM_SLEEP_SMP=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
# CONFIG_PL310_ERRATA_769419 is not set
CONFIG_PM_SLEEP_SMP=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RFS_ACCEL=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RFS_ACCEL=y
CONFIG_RATIONAL=y
# CONFIG_RAVE_SP_CORE is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RATIONAL=y
# CONFIG_RAVE_SP_CORE is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_TRACE=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_TRACE=y
CONFIG_RATIONAL=y
# CONFIG_RAVE_SP_CORE is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RATIONAL=y
# CONFIG_RAVE_SP_CORE is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_TRACE=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_TRACE=y
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REGMAP=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REGMAP=y
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
CONFIG_RAS=y
CONFIG_RATIONAL=y
CONFIG_RCU_CPU_STALL_TIMEOUT=21
-# CONFIG_RCU_EXPERT is not set
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REFCOUNT_FULL=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_REFCOUNT_FULL=y