From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Marc <marvin24@gmx.de>
Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: clock skew on B/W G3
Date: Wed, 05 Oct 2005 08:14:54 +1000 [thread overview]
Message-ID: <1128464094.6417.31.camel@gaston> (raw)
In-Reply-To: <200510040814.07188.marvin24@gmx.de>
On Tue, 2005-10-04 at 08:14 +0200, Marc wrote:
> Hi,
>
> given that this option causes problems on non i386 systems, may I propose to
> mark CONFIG_HZ as broken on these architectures and/or use a default value of
> 1000 ? I guess this issue can't be fixed in a sane way until 2.6.14 is out.
The problem is indeed in via_calibrate_decr(). This routine works on
HZ/100 so it will not do any good with HZ not beeing a multiple of 100.
Can you test this patch ?
Index: linux-work/arch/ppc/platforms/pmac_time.c
===================================================================
--- linux-work.orig/arch/ppc/platforms/pmac_time.c 2005-09-22 14:06:18.000000000 +1000
+++ linux-work/arch/ppc/platforms/pmac_time.c 2005-10-05 08:14:17.000000000 +1000
@@ -195,7 +195,7 @@
;
dend = get_dec();
- tb_ticks_per_jiffy = (dstart - dend) / (6 * (HZ/100));
+ tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100);
tb_to_us = mulhwu_scale_factor(dstart - dend, 60000);
printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n",
next prev parent reply other threads:[~2005-10-04 22:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-10-03 14:18 clock skew on B/W G3 Rune Torgersen
2005-10-04 6:14 ` Marc
2005-10-04 22:10 ` Benjamin Herrenschmidt
2005-10-04 22:14 ` Benjamin Herrenschmidt [this message]
2005-10-05 6:34 ` Marc
2005-10-04 12:48 ` Paul Mackerras
-- strict thread matches above, loose matches on Subject: below --
2005-10-04 19:22 Rune Torgersen
2005-10-04 15:15 Rune Torgersen
2005-10-04 19:14 ` George Anzinger
2005-10-01 12:29 marvin24
2005-10-02 16:46 ` Marc
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