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From: Petr Mladek <pmladek@suse.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: xiang xiao <xiaoxiang781216@gmail.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: Thu, 14 Feb 2019 09:48:55 +0100	[thread overview]
Message-ID: <20190214084855.xyug7cmnrybdcmos@pathway.suse.cz> (raw)
In-Reply-To: <20190213093154.7af84743@gandalf.local.home>

On Wed 2019-02-13 09:31:54, Steven Rostedt wrote:
> On Wed, 13 Feb 2019 22:00:04 +0800
> xiang xiao <xiaoxiang781216@gmail.com> wrote:
> > Here is a sample output with this patch:
> > [   10.991426] virtio_rpmsg_bus virtio1: rpmsg host is online
> > [   10.991443] remoteproc remoteproc1: registered virtio1 (type 7)
> > [   10.991450] remoteproc remoteproc1: remote processor
> > f9210000.toppwr:sen-rproc is now up
> > [   10.993715] virtio_rpmsg_bus virtio1: creating channel
> > rpmsg-ttySENSOR addr 0x1
> > [   10.994606] virtio_rpmsg_bus virtio1: creating channel rpmsg-ttyGPS addr 0x2
> > [   10.995236] virtio_rpmsg_bus virtio1: creating channel rpmsg-clk addr 0x3
> > [   10.995702] virtio_rpmsg_bus virtio1: creating channel rpmsg-syslog addr 0x4
> > [   10.996197] virtio_rpmsg_bus virtio1: creating channel rpmsg-rtc addr 0x5
> > [   10.997297] virtio_rpmsg_bus virtio1: creating channel rpmsg-hostfs addr 0x6
> > [   10.999842] virtio_rpmsg_bus virtio1: creating channel rpmsg-usrsock addr 0x7
> > [     0.007680] sensor: NuttX sensor 7.28 e3c2ecb Feb 12 2019 16:53:49
> > arm song/banks
> > ^^^^^^^^^^^^^
> > [   11.918177] random: crng init done
> > [   12.567362] e2fsck: e2fsck 1.42.9 (28-Dec-2013)
> > 
> > Without this patch:
> > [   10.991426] virtio_rpmsg_bus virtio1: rpmsg host is online
> > [   10.991443] remoteproc remoteproc1: registered virtio1 (type 7)
> > [   10.991450] remoteproc remoteproc1: remote processor
> > f9210000.toppwr:sen-rproc is now up
> > [   10.993715] virtio_rpmsg_bus virtio1: creating channel
> > rpmsg-ttySENSOR addr 0x1
> > [   10.994606] virtio_rpmsg_bus virtio1: creating channel rpmsg-ttyGPS addr 0x2
> > [   10.995236] virtio_rpmsg_bus virtio1: creating channel rpmsg-clk addr 0x3
> > [   10.995702] virtio_rpmsg_bus virtio1: creating channel rpmsg-syslog addr 0x4
> > [   10.996197] virtio_rpmsg_bus virtio1: creating channel rpmsg-rtc addr 0x5
> > [   10.997297] virtio_rpmsg_bus virtio1: creating channel rpmsg-hostfs addr 0x6
> > [   10.999842] virtio_rpmsg_bus virtio1: creating channel rpmsg-usrsock addr 0x7
> > [   11.105345][     0.007680] sensor: NuttX sensor 7.28 e3c2ecb Feb 12
> > 2019 16:53:49 arm song/banks
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^
> > [   11.918177] random: crng init done
> > [   12.567362] e2fsck: e2fsck 1.42.9 (28-Dec-2013)
> > 
> > Which one do you think better?
> 
> Honestly, the one without the patch.
> 
> Seriously, it also makes it easy to see where that message happened
> with respect to the other printks. With your patch, we would have no
> idea, and if I was a normal user, unaware of this patch, I would
> probably submit a bug report claiming that something is wrong with the
> timestamps.

Just for record. I agree with Steven and Sergey here. The two clocks
are too out of sync. "Randomly" and quietly replacing one with
the other would cause more harm than good from my point of view.

Best Regards,
Petr

  parent reply	other threads:[~2019-02-14  8:49 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
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 [this message]
2019-02-13  0:48 ` Sergey Senozhatsky
2019-02-13  6:25   ` xiang xiao

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