Documentation: add print bitmap description

as the commit: "lib/vsprintf: implement bitmap printing through
'%*pb[l]'" add an easy way to print bitmaps. so printk-formats.txt
should reflect it.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Wang Long 2015-02-26 03:28:25 +00:00 committed by Jonathan Corbet
parent ad4a6ebeff
commit d072496155
1 changed files with 9 additions and 0 deletions

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@ -239,6 +239,15 @@ s64 SHOULD be printed with %lld/%llx:
printk("%lld", s64_var); printk("%lld", s64_var);
bitmap and its derivatives such as cpumask and nodemask:
%*pb 0779
%*pbl 0,3-6,8-10
For printing bitmap and its derivatives such as cpumask and nodemask,
%*pb output 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.
If <type> is dependent on a config option for its size (e.g., sector_t, If <type> is dependent on a config option for its size (e.g., sector_t,
blkcnt_t) or is architecture-dependent for its size (e.g., tcflag_t), use a blkcnt_t) or is architecture-dependent for its size (e.g., tcflag_t), use a
format specifier of its largest possible type and explicitly cast to it. format specifier of its largest possible type and explicitly cast to it.