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",
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Marc <marvin24@gmx.de>
Cc: Rune Torgersen <runet@innovsys.com>,
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: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-10-03 14:18 clock skew on B/W G3 Rune Torgersen
2005-10-03 14:18 ` Rune Torgersen
2005-10-04 6:14 ` Marc
2005-10-04 6:14 ` Marc
2005-10-04 22:10 ` Benjamin Herrenschmidt
2005-10-04 22:10 ` Benjamin Herrenschmidt
2005-10-04 22:14 ` Benjamin Herrenschmidt [this message]
2005-10-04 22:14 ` Benjamin Herrenschmidt
2005-10-05 6:34 ` Marc
2005-10-05 6:34 ` Marc
2005-10-04 12:48 ` Paul Mackerras
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 19:22 ` Rune Torgersen
2005-10-04 15:15 Rune Torgersen
2005-10-04 15:15 ` Rune Torgersen
2005-10-04 19:14 ` George Anzinger
2005-10-04 19:14 ` George Anzinger
2005-10-01 12:29 marvin24
2005-10-02 16:46 ` Marc
2005-10-02 16:46 ` Marc
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1128464094.6417.31.camel@gaston \
--to=benh@kernel.crashing.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=marvin24@gmx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.