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| author | Yury Norov <yury.norov@gmail.com> | 2021-04-21 05:13:25 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-05-11 00:38:20 +0200 |
| commit | b18def121f077857ccf92fc620366e19850bc297 (patch) | |
| tree | b19cef760cf5a2e53c37633b6cfb365c75c6abac /Documentation/admin-guide | |
| parent | Linux 5.13-rc1 (diff) | |
| download | linux-b18def121f077857ccf92fc620366e19850bc297.tar.xz linux-b18def121f077857ccf92fc620366e19850bc297.zip | |
bitmap_parse: Support 'all' semantics
RCU code supports an 'all' group as a special case when parsing rcu_nocbs
parameter. This patch moves the 'all' support to the core bitmap_parse
code, so that all bitmap users can enjoy this extension.
Moving 'all' parsing to a bitmap_parse level also allows users to pass
patterns together with 'all' in regular group:pattern format, for example,
"rcu_nocbs=all:1/2" would offload all the even-numbered CPUs regardless
of the number of CPUs on the system.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 3996b54158bf..01ba293a2d70 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -76,6 +76,11 @@ 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). +The special case-tolerant group name "all" has a meaning of selecting all CPUs, +so that "nohz_full=all" is the equivalent of "nohz_full=0-N". + +The semantics of "N" and "all" is supported on a level of bitmaps and holds for +all users of bitmap_parse(). This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable |