blkparse: man: add absolute timestamp printing option

The functionality of printing out absolute timestamps has been
implemented in code but not documented in man pages.

When comparing the timings of related events with block I/O traces,
the absolute timestams play a key role.  I think that the
documentation of this might be beneficial to blktrace users.

The related commit was done in 2006 as follows,

> commit 7bd4fd0a4fca645bb50a641afac1e460a4e32dfd
> Author: Olaf Kirch <okir@lst.de>
> Date:   Fri Dec 1 10:34:11 2006 +0100
>
>     [PATCH] Add timestamp support
>
>     Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
>

URL of the above patch,
https://git.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git/commit/?id=7bd4fd0a4fca645bb50a641afac1e460a4e32dfd

Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Hiroaki Mihara <hmihara@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/doc/blkparse.1 b/doc/blkparse.1
index 627b7b1cce3d3ff5f410b0f191da2eab7af99a29..e494b6eca2237e79cd682142be462879713ce0be 100644 (file)
--- a/doc/blkparse.1
+++ b/doc/blkparse.1
@@ -368,6 +368,9 @@ Elapsed value in microseconds (\fI\-t\fR command line option)
 .IP \fBU\fR 4
 Payload unsigned integer
 
+.IP \fBz\fR 4
+The absolute time, as local time in your time zone, with no date displayed
+
 .PP
 Note that the user can optionally specify field display width, and optionally a
 left-aligned specifier. These precede field specifiers, with a '%' character,