RCU code supports a special group 'all' which selects all bits in a bitmap. We have recently added 'N' extension for bitmap parse, so that '0-N' would have exactly the same meaning as 'all'. But because the 'all' is already used by RCU, it would be reasonable to support it in core bitmap code as a common and easy-readable alias for '0-N'. Moving the 'all' support to core bitmap code adds another level of flexibility for system configuration by supporting patterns. For example, every second bit in cpumask may be selected like this: isolcpus=all:1/2 v2: - cleanup patch 1; - in patch 2 explain why dropping legacy comment. Yury Norov (2): bitmap_parse: support 'all' semantics rcu/tree_plugin: don't handle the case of 'all' CPU range Documentation/admin-guide/kernel-parameters.rst | 5 +++++ kernel/rcu/tree_plugin.h | 9 +++------ lib/bitmap.c | 9 +++++++++ lib/test_bitmap.c | 7 +++++++ 4 files changed, 24 insertions(+), 6 deletions(-) -- 2.25.1
