Re: [GIT pull] printk updates for 4.15

From: Kevin Easton <kevin@guarana.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Mark Salyzyn <salyzyn@android.com>,
	Petr Mladek <pmladek@suse.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Prarit Bhargava <prarit@redhat.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	John Stultz <john.stultz@linaro.org>
Subject: Re: [GIT pull] printk updates for 4.15
Date: Mon, 20 Nov 2017 01:20:57 -0500	[thread overview]
Message-ID: <20171120062057.GA31822@la.guarana.org> (raw)
In-Reply-To: <alpine.DEB.2.20.1711180123360.2186@nanos>

On Sat, Nov 18, 2017 at 01:26:07AM +0100, Thomas Gleixner wrote:
> On Thu, 16 Nov 2017, Thomas Gleixner wrote:
> > I hope that I can find a few spare cycles to whip up a POC patch which does
> > not make stuff fall apart immediately.
> 
> Here you go. It survived suspend resume in a VM.
> 
> Thanks,
> 
> 	tglx
> 
> 8<------------------------
> Subject: timekeeping: Make monotonic behave like boottime
> From: Thomas Gleixner <tglx@linutronix.de>
> Date: Fri, 17 Nov 2017 11:46:48 +0100
> 
> Clock MONOTONIC is not fast forwarded by the time spent in suspend on
> resume. This is only done for BOOTTIME.
> 
> It would be desired to get rid of that difference, but the difference
> between clock MONOTONIC and clock BOOTTIME is well documented so there
> might be applications which depend on that behaviour.

As a comment from the userspace peanut gallery, I personally hope this
does pass muster.  The existing POSIX wording implies that MONOTONIC
doesn't stop counting over suspend, and that's what you need when you
want to know the time elapsed between two external events.

    - Kevin
> 