From mboxrd@z Thu Jan  1 00:00:00 1970
From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Date: Wed, 18 Feb 2009 22:13:36 -0500
Subject: [ltt-dev] [patch 4/7] omap lttng use iter div
In-Reply-To: <20090219092852.9553.A69D9226@jp.fujitsu.com>
References: <20090218074703.163707091@polymtl.ca>
	<20090218075132.874024744@polymtl.ca>
	<20090219092852.9553.A69D9226@jp.fujitsu.com>
Message-ID: <20090219031336.GB6922@Krystal>

* KOSAKI Motohiro (kosaki.motohiro at jp.fujitsu.com) wrote:
> > ARM does no seem to like u64 div in math64.h. Use the "iter" version.
> > 
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at polymtl.ca>
> > ---
> >  kernel/trace/trace-clock-32-to-64.c |    8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > Index: linux-omap-2.6/kernel/trace/trace-clock-32-to-64.c
> > ===================================================================
> > --- linux-omap-2.6.orig/kernel/trace/trace-clock-32-to-64.c	2009-02-16 00:39:18.000000000 +0000
> > +++ linux-omap-2.6/kernel/trace/trace-clock-32-to-64.c	2009-02-16 00:41:42.000000000 +0000
> > @@ -153,13 +153,15 @@
> >   */
> >  static int __init precalc_stsc_interval(void)
> >  {
> > +	u64 rem_freq, rem_interval;
> > +
> >  	precalc_expire =
> > -		div_u64(HW_BITMASK,
> > -		 ((div_u64(trace_clock_frequency(), HZ)
> > +		__iter_div_u64_rem(HW_BITMASK,
> > +		 ((__iter_div_u64_rem(trace_clock_frequency(), HZ, &rem_freq)
> >  		     * trace_clock_freq_scale())
> >  		    << 1)
> >  		 - 1
> > -		 - (EXPECTED_INTERRUPT_LATENCY * HZ / 1000))
> > +		 - (EXPECTED_INTERRUPT_LATENCY * HZ / 1000), &rem_interval)
> >  		>> 1;
> >  	WARN_ON(precalc_expire == 0);
> >  	printk(KERN_DEBUG "Synthetic TSC timer will fire each %u jiffies.\n",
> 
> Instead, implement div_u64() for arm is bad idea?
> 
> 

This is indeed a very good idea ! Is anyone willing to do it ?

Mathieu

> 
> 
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> 

-- 
Mathieu Desnoyers
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