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From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: xiang xiao <xiaoxiang781216@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Petr Mladek <pmladek@suse.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	linux-kernel@vger.kernel.org, Xiang Xiao <xiaoxiang@xiaomi.com>
Subject: Re: [PATCH] printk: add KERN_NOTIME to skip the timestamp
Date: Wed, 13 Feb 2019 17:08:52 +0900	[thread overview]
Message-ID: <20190213080852.GA1702@jagdpanzerIV> (raw)
In-Reply-To: <CAH2Cfb8ENK6f1BKvD4oqGhRjQU6cU5ii_OREcPtjwZqP=1qAeQ@mail.gmail.com>

On (02/13/19 15:14), xiang xiao wrote:
>
> But how can I precisely control timestamp on/off per message
> through sysfs node?
>

Hmm. I don't know how many kernel printk-s you have and how often
do you write to kmsg. I was thinking about something like this:

	echo 0 > /...printk.../time
	dump buffer to /dev/kmsg
	echo 1 > /...printk../time

- If you would have several kernel printk-s in the meantime, then
  those would not have timestamps, but you kinda can roughly guess
  it

	write [1243] foo > /dev/kmsg
	write [1244] foo > /dev/kmsg
		<< printk(bar)               <timestamp ~[1244,1245]>
	write [1245] foo > /dev/kmsg

Maybe this won't suffice.

	-ss

  reply	other threads:[~2019-02-13  8:08 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-12 18:11 [PATCH] printk: add KERN_NOTIME to skip the timestamp Xiang Xiao
2019-02-12 19:46 ` Steven Rostedt
2019-02-13  6:19   ` xiang xiao
2019-02-13  6:29     ` Sergey Senozhatsky
2019-02-13  6:38       ` Sergey Senozhatsky
2019-02-13  7:14         ` xiang xiao
2019-02-13  8:08           ` Sergey Senozhatsky [this message]
2019-02-13  8:52             ` xiang xiao
2019-02-13 13:19     ` Petr Mladek
2019-02-13 13:49       ` xiang xiao
2019-02-13 13:47     ` Steven Rostedt
2019-02-13 14:00       ` xiang xiao
2019-02-13 14:31         ` Steven Rostedt
2019-02-13 16:25           ` xiang xiao
2019-02-14  1:26           ` Sergey Senozhatsky
2019-02-14  8:48           ` Petr Mladek
2019-02-13  0:48 ` Sergey Senozhatsky
2019-02-13  6:25   ` xiang xiao

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