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>
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 5a615c1..255a061 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -239,6 +239,15 @@
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,
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.