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authorWang Long <long.wanglong@huawei.com>2015-02-26 03:28:25 +0000
committerJonathan Corbet <corbet@lwn.net>2015-03-20 07:41:55 -0600
commitd0724961552f2b7da89e4b822b985f3c9fd13b79 (patch)
tree0fdcb4567e61e6313109c55e4acce7f43d21342f /Documentation/printk-formats.txt
parentad4a6ebeffd2767bdcdec9e1acea7ffc00d5be2d (diff)
downloadkernel-d0724961552f2b7da89e4b822b985f3c9fd13b79.tar.gz
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>
Diffstat (limited to 'Documentation/printk-formats.txt')
-rw-r--r--Documentation/printk-formats.txt9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 5a615c14f75d..255a061e4309 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -239,6 +239,15 @@ s64 SHOULD be printed with %lld/%llx:
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.