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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-28 12:00:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-28 12:00:13 -0700
commit9a45da9270b64b14e154093c28f746d861ab8c61 (patch)
treebbe75582da2e9d5f9cce4bc39a6cc32fcc171ee1 /Documentation
parent68a32ba14177d4a21c4a9a941cf1d7aea86d436f (diff)
parent120b566d1df22a0a4543ac0e8aef875c49dd2c21 (diff)
Merge tag 'core-rcu-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar: - Support for "N" as alias for last bit in bitmap parsing library (eg using syntax like "nohz_full=2-N") - kvfree_rcu updates - mm_dump_obj() updates. (One of these is to mm, but was suggested by Andrew Morton.) - RCU callback offloading update - Polling RCU grace-period interfaces - Realtime-related RCU updates - Tasks-RCU updates - Torture-test updates - Torture-test scripting updates - Miscellaneous fixes * tag 'core-rcu-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) rcutorture: Test start_poll_synchronize_rcu() and poll_state_synchronize_rcu() rcu: Provide polling interfaces for Tiny RCU grace periods torture: Fix kvm.sh --datestamp regex check torture: Consolidate qemu-cmd duration editing into kvm-transform.sh torture: Print proper vmlinux path for kvm-again.sh runs torture: Make TORTURE_TRUST_MAKE available in kvm-again.sh environment torture: Make kvm-transform.sh update jitter commands torture: Add --duration argument to kvm-again.sh torture: Add kvm-again.sh to rerun a previous torture-test torture: Create a "batches" file for build reuse torture: De-capitalize TORTURE_SUITE torture: Make upper-case-only no-dot no-slash scenario names official torture: Rename SRCU-t and SRCU-u to avoid lowercase characters torture: Remove no-mpstat error message torture: Record kvm-test-1-run.sh and kvm-test-1-run-qemu.sh PIDs torture: Record jitter start/stop commands torture: Extract kvm-test-1-run-qemu.sh from kvm-test-1-run.sh torture: Record TORTURE_KCONFIG_GDB_ARG in qemu-cmd torture: Abstract jitter.sh start/stop into scripts rcu: Provide polling interfaces for Tree RCU grace periods ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/RCU/RTFP.txt2
-rw-r--r--Documentation/admin-guide/kernel-parameters.rst7
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt16
3 files changed, 21 insertions, 4 deletions
diff --git a/Documentation/RCU/RTFP.txt b/Documentation/RCU/RTFP.txt
index 3b0876c77355..588d97366a46 100644
--- a/Documentation/RCU/RTFP.txt
+++ b/Documentation/RCU/RTFP.txt
@@ -847,7 +847,7 @@ Symposium on Distributed Computing}
'It's entirely possible that the current user could be replaced
by RCU and/or seqlocks, and we could get rid of brlocks entirely.'
.
- Steve Hemminger responds by replacing them with RCU.
+ Stephen Hemminger responds by replacing them with RCU.
}
}
diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst
index 24302cad174a..3996b54158bf 100644
--- a/Documentation/admin-guide/kernel-parameters.rst
+++ b/Documentation/admin-guide/kernel-parameters.rst
@@ -68,6 +68,13 @@ For example one can add to the command line following parameter:
where the final item represents CPUs 100,101,125,126,150,151,...
+The value "N" can be used to represent the numerically last CPU on the system,
+i.e "foo_cpus=16-N" would be equivalent to "16-31" on a 32 core system.
+
+Keep in mind that "N" is dynamic, so if system changes cause the bitmap width
+to change, such as less cores in the CPU list, then N and any ranges using N
+will also change. Use the same on a small 4 core system, and "16-N" becomes
+"16-3" and now the same boot input will be flagged as invalid (start > end).
This document may not be entirely up to date and comprehensive. The command
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 70a30f65bfca..fa08ec0dfbe7 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4077,9 +4077,7 @@
see CONFIG_RAS_CEC help text.
rcu_nocbs= [KNL]
- The argument is a cpu list, as described above,
- except that the string "all" can be used to
- specify every CPU on the system.
+ The argument is a cpu list, as described above.
In kernels built with CONFIG_RCU_NOCB_CPU=y, set
the specified list of CPUs to be no-callback CPUs.
@@ -4268,6 +4266,18 @@
rcuscale.kfree_rcu_test= [KNL]
Set to measure performance of kfree_rcu() flooding.
+ rcuscale.kfree_rcu_test_double= [KNL]
+ Test the double-argument variant of kfree_rcu().
+ If this parameter has the same value as
+ rcuscale.kfree_rcu_test_single, both the single-
+ and double-argument variants are tested.
+
+ rcuscale.kfree_rcu_test_single= [KNL]
+ Test the single-argument variant of kfree_rcu().
+ If this parameter has the same value as
+ rcuscale.kfree_rcu_test_double, both the single-
+ and double-argument variants are tested.
+
rcuscale.kfree_nthreads= [KNL]
The number of threads running loops of kfree_rcu().