From: Ingo Molnar <mingo@elte.hu>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: printk_time to use tsc before cpu_clock is ready
Date: Wed, 27 Aug 2008 10:02:38 +0200 [thread overview]
Message-ID: <20080827080238.GC4453@elte.hu> (raw)
In-Reply-To: <1219823233.6462.38.camel@twins>
* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Wed, 2008-08-27 at 09:42 +0200, Ingo Molnar wrote:
> > * Yinghai Lu <yhlu.kernel@gmail.com> wrote:
> >
> > > +static unsigned long long tsc_clock(int cpu)
> > > +{
> > > + unsigned long long t;
> > > +
> > > + rdtscll(t);
> > > +
> > > + return t;
> > > +}
> >
> > hm, i'm not sure i like the whole direction - this reintroduces
> > printk_clock in essence.
> >
> > how about initializing cpu_clock() sooner, so that printk timestamps
> > start ticking as soon as possible?
>
> which will make some archs quite unhappy iirc, see those arm and ia64
> bugs I caused the other day.
that's OK - that still allows arches to start their clocks whenever they
want to. But also add the possibility for architectures to initialize
things even sooner.
Ingo
next prev parent reply other threads:[~2008-08-27 8:03 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-27 7:38 [PATCH] printk_time: prepare stub for using other than cpu_clock Yinghai Lu
2008-08-27 7:38 ` [PATCH] x86: printk_time to use tsc before cpu_clock is ready Yinghai Lu
2008-08-27 7:42 ` Ingo Molnar
2008-08-27 7:47 ` Peter Zijlstra
2008-08-27 8:02 ` Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-07-29 10:08 [PATCH] printk_time: prepare stub for using other than cpu_clock Yinghai Lu
2008-07-29 10:09 ` [PATCH] x86: printk_time to use tsc before cpu_clock is ready Yinghai Lu
2008-07-29 10:13 ` Peter Zijlstra
2008-07-29 10:18 ` Yinghai Lu
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