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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 14:31:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 14:31:33 -0700
commit8f0cb6660acb0d4756df880a3e60e73daa9c244e (patch)
tree9f14396bed65f82b94f7bb2425ffb2f0cbd4519a /Documentation/admin-guide
parent5ece08178d6567db5ef0090b1ae7f795c3c36161 (diff)
parentc1cc4784ce6e8cceff1013709abd74bcbf7fbf24 (diff)
Merge tag 'core-rcu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar: - kfree_rcu updates - RCU tasks updates - Read-side scalability tests - SRCU updates - Torture-test updates - Documentation updates - Miscellaneous fixes * tag 'core-rcu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (109 commits) torture: Remove obsolete "cd $KVM" torture: Avoid duplicate specification of qemu command torture: Dump ftrace at shutdown only if requested torture: Add kvm-tranform.sh script for qemu-cmd files torture: Add more tracing crib notes to kvm.sh torture: Improve diagnostic for KCSAN-incapable compilers torture: Correctly summarize build-only runs torture: Pass --kmake-arg to all make invocations rcutorture: Check for unwatched readers torture: Abstract out console-log error detection torture: Add a stop-run capability torture: Create qemu-cmd in --buildonly runs rcu/rcutorture: Replace 0 with false torture: Add --allcpus argument to the kvm.sh script torture: Remove whitespace from identify_qemu_vcpus output rcutorture: NULL rcu_torture_current earlier in cleanup code rcutorture: Handle non-statistic bang-string error messages torture: Set configfile variable to current scenario rcutorture: Add races with task-exit processing locktorture: Use true and false to assign to bool variables ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt68
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index fb95fad81c79..d35fd3ced0db 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4038,6 +4038,14 @@
latencies, which will choose a value aligned
with the appropriate hardware boundaries.
+ rcutree.rcu_min_cached_objs= [KNL]
+ Minimum number of objects which are cached and
+ maintained per one CPU. Object size is equal
+ to PAGE_SIZE. The cache allows to reduce the
+ pressure to page allocator, also it makes the
+ whole algorithm to behave better in low memory
+ condition.
+
rcutree.jiffies_till_first_fqs= [KNL]
Set delay from grace-period initialization to
first attempt to force quiescent states.
@@ -4258,6 +4266,20 @@
Set time (jiffies) between CPU-hotplug operations,
or zero to disable CPU-hotplug testing.
+ rcutorture.read_exit= [KNL]
+ Set the number of read-then-exit kthreads used
+ to test the interaction of RCU updaters and
+ task-exit processing.
+
+ rcutorture.read_exit_burst= [KNL]
+ The number of times in a given read-then-exit
+ episode that a set of read-then-exit kthreads
+ is spawned.
+
+ rcutorture.read_exit_delay= [KNL]
+ The delay, in seconds, between successive
+ read-then-exit testing episodes.
+
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
@@ -4407,6 +4429,45 @@
reboot_cpu is s[mp]#### with #### being the processor
to be used for rebooting.
+ refscale.holdoff= [KNL]
+ Set test-start holdoff period. The purpose of
+ this parameter is to delay the start of the
+ test until boot completes in order to avoid
+ interference.
+
+ refscale.loops= [KNL]
+ Set the number of loops over the synchronization
+ primitive under test. Increasing this number
+ reduces noise due to loop start/end overhead,
+ but the default has already reduced the per-pass
+ noise to a handful of picoseconds on ca. 2020
+ x86 laptops.
+
+ refscale.nreaders= [KNL]
+ Set number of readers. The default value of -1
+ selects N, where N is roughly 75% of the number
+ of CPUs. A value of zero is an interesting choice.
+
+ refscale.nruns= [KNL]
+ Set number of runs, each of which is dumped onto
+ the console log.
+
+ refscale.readdelay= [KNL]
+ Set the read-side critical-section duration,
+ measured in microseconds.
+
+ refscale.scale_type= [KNL]
+ Specify the read-protection implementation to test.
+
+ refscale.shutdown= [KNL]
+ Shut down the system at the end of the performance
+ test. This defaults to 1 (shut it down) when
+ rcuperf is built into the kernel and to 0 (leave
+ it running) when rcuperf is built as a module.
+
+ refscale.verbose= [KNL]
+ Enable additional printk() statements.
+
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/admin-guide/cgroup-v1/cpusets.rst.
@@ -5082,6 +5143,13 @@
Prevent the CPU-hotplug component of torturing
until after init has spawned.
+ torture.ftrace_dump_at_shutdown= [KNL]
+ Dump the ftrace buffer at torture-test shutdown,
+ even if there were no errors. This can be a
+ very costly operation when many torture tests
+ are running concurrently, especially on systems
+ with rotating-rust storage.
+
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]