docs: core-api/printk-formats.rst: Clarify formatting {cpu,node}mask

Clarify how to pass the field width for bitmaps, and mention the helper
macros that are available to ease printing cpumask and nodemask.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201110144121.3278667-1-geert+renesas@glider.be
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Geert Uytterhoeven 2020-11-10 15:41:21 +01:00 committed by Jonathan Corbet
parent bfe7bf3114
commit 04d0608b44

View File

@ -531,7 +531,9 @@ For printing bitmap and its derivatives such as cpumask and nodemask,
%*pb outputs the bitmap with field width as the number of bits and %*pbl
output the bitmap as range list with field width as the number of bits.
Passed by reference.
The field width is passed by value, the bitmap is passed by reference.
Helper macros cpumask_pr_args() and nodemask_pr_args() are available to ease
printing cpumask and nodemask.
Flags bitfields such as page flags, gfp_flags
---------------------------------------------