[PATCH 0/5] Enable setexpr command to print cpu-list like bitmaps

lukas.funke-oss at weidmueller.com lukas.funke-oss at weidmueller.com
Mon Dec 11 13:20:46 CET 2023


From: Lukas Funke <lukas.funke at weidmueller.com>


This series enables the 'setexpr' command to print "cpu list"-like
bitmaps based on the printk format specifier [1].

One use-case is to pass cpu list [2] based kernel parameter like
'isolcpu', 'nohz_full', irq affinity or RCU related CPU parameter to
the kernel via a separate firmware variable without exposing the
'bootargs' variable to directly.

Example:

setexpr isolcpu_bootarg=%32pbl $myCPUisolation
&& env set bootargs "$isolcpu_bootarg"
&& bootm

[1] https://www.kernel.org/doc/Documentation/printk-formats.txt
[2] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html



Lukas Funke (5):
  sandbox: add generic find_next_zero_bit implementation
  linux: bitmap.h: add 'for_each_set_bitrange' iteration macro
  test: cmd: setexptr: Add tests for bitmap string format
  lib: vsprintf: enable '%*pb[l]' format specifier
  cmd: printf: forward '%p' format string specifier

 arch/sandbox/include/asm/bitops.h | 16 ++++++-
 cmd/printf.c                      | 29 ++++++++++++
 include/linux/bitmap.h            |  7 +++
 lib/vsprintf.c                    | 75 +++++++++++++++++++++++++++++++
 test/cmd/setexpr.c                |  9 ++++
 5 files changed, 134 insertions(+), 2 deletions(-)

-- 
2.30.2



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