From: "Joakim Tjernlund" <joakim.tjernlund@transmode.se>
To: "'David Brownell'" <david-b@pacbell.net>,
"'Benjamin Herrenschmidt'" <benh@kernel.crashing.org>
Cc: akpm@osdl.org, 'Alessandro Zummo' <alessandro.zummo@towertech.it>,
'Andi Kleen' <ak@muc.de>,
'Linux Kernel Mailing List' <linux-kernel@vger.kernel.org>,
ralf@linux-mips.org, linuxppc-dev@ozlabs.org,
lethal@linux-sh.org, paulus@samba.org, kkojima@rr.iij4u.or.jp,
davem@davemloft.net, rmk@arm.linux.org.uk
Subject: RE: NTP time sync
Date: Sun, 26 Nov 2006 12:04:54 +0100 [thread overview]
Message-ID: <009a01c7114a$b429f850$020120ac@Jocke> (raw)
In-Reply-To: <200611251522.19900.david-b@pacbell.net>
> -----Original Message-----
> From:
> linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozlabs.org
> [mailto:linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozl
> abs.org] On Behalf Of David Brownell
> Sent: den 26 november 2006 00:22
> To: Benjamin Herrenschmidt
> Cc: akpm@osdl.org; Alessandro Zummo; linuxppc-dev@ozlabs.org;
> lethal@linux-sh.org; Linux Kernel Mailing List;
> ralf@linux-mips.org; Andi Kleen; paulus@samba.org;
> rmk@arm.linux.org.uk; davem@davemloft.net; kkojima@rr.iij4u.or.jp
> Subject: Re: NTP time sync
>
> On Thursday 23 November 2006 3:00 am, Benjamin Herrenschmidt wrote:
> >
> > Couldn't we have a transition period by making the kernel
> not rely on
> > interrupts ? if the NTP irq code just triggers a work
> queue, then all of
> > a sudden, all of the RTC drivers can be used and the
> latency is small.
> > That might well be a good enough solution and is very simple.
>
> Good point. Of course, one issue is that the NTP sync code all
> seems to be platform-specific right now ... just like the code
> to set the system time from an RTC at boot (except for the new
> RTC framework stuff) and after resume.
>
> - Dave
Looking at rtc-dev.c I don't see a MARJOR number assigned to /dev/rtcN. Seems like
it is dynamically allocated to whatever major number that is free.
Is that the way it is supposed to be? How do I create a static /dev/rtcN in my /dev
directory if the major number isn't fixed?
Maybe I am just missing something, feel free to correct me :)
Jocke
WARNING: multiple messages have this Message-ID (diff)
From: "Joakim Tjernlund" <joakim.tjernlund@transmode.se>
To: "'David Brownell'" <david-b@pacbell.net>,
"'Benjamin Herrenschmidt'" <benh@kernel.crashing.org>
Cc: <akpm@osdl.org>,
"'Alessandro Zummo'" <alessandro.zummo@towertech.it>,
<linuxppc-dev@ozlabs.org>, <lethal@linux-sh.org>,
"'Linux Kernel Mailing List'" <linux-kernel@vger.kernel.org>,
<ralf@linux-mips.org>, "'Andi Kleen'" <ak@muc.de>,
<paulus@samba.org>, <rmk@arm.linux.org.uk>, <davem@davemloft.net>,
<kkojima@rr.iij4u.or.jp>
Subject: RE: NTP time sync
Date: Sun, 26 Nov 2006 12:04:54 +0100 [thread overview]
Message-ID: <009a01c7114a$b429f850$020120ac@Jocke> (raw)
In-Reply-To: <200611251522.19900.david-b@pacbell.net>
> -----Original Message-----
> From:
> linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozlabs.org
> [mailto:linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozl
> abs.org] On Behalf Of David Brownell
> Sent: den 26 november 2006 00:22
> To: Benjamin Herrenschmidt
> Cc: akpm@osdl.org; Alessandro Zummo; linuxppc-dev@ozlabs.org;
> lethal@linux-sh.org; Linux Kernel Mailing List;
> ralf@linux-mips.org; Andi Kleen; paulus@samba.org;
> rmk@arm.linux.org.uk; davem@davemloft.net; kkojima@rr.iij4u.or.jp
> Subject: Re: NTP time sync
>
> On Thursday 23 November 2006 3:00 am, Benjamin Herrenschmidt wrote:
> >
> > Couldn't we have a transition period by making the kernel
> not rely on
> > interrupts ? if the NTP irq code just triggers a work
> queue, then all of
> > a sudden, all of the RTC drivers can be used and the
> latency is small.
> > That might well be a good enough solution and is very simple.
>
> Good point. Of course, one issue is that the NTP sync code all
> seems to be platform-specific right now ... just like the code
> to set the system time from an RTC at boot (except for the new
> RTC framework stuff) and after resume.
>
> - Dave
Looking at rtc-dev.c I don't see a MARJOR number assigned to /dev/rtcN. Seems like
it is dynamically allocated to whatever major number that is free.
Is that the way it is supposed to be? How do I create a static /dev/rtcN in my /dev
directory if the major number isn't fixed?
Maybe I am just missing something, feel free to correct me :)
Jocke
next prev parent reply other threads:[~2006-11-26 11:05 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-22 19:36 NTP time sync Alessandro Zummo
2006-11-22 19:36 ` Alessandro Zummo
2006-11-22 19:51 ` Russell King
2006-11-22 19:51 ` Russell King
2006-11-22 20:26 ` Alessandro Zummo
2006-11-22 20:26 ` Alessandro Zummo
2006-11-22 19:55 ` David Brownell
2006-11-22 19:55 ` David Brownell
2006-11-22 20:23 ` Alessandro Zummo
2006-11-22 20:23 ` Alessandro Zummo
2006-11-23 1:48 ` Gabriel Paubert
2006-11-23 1:48 ` Gabriel Paubert
2006-11-23 10:54 ` Andi Kleen
2006-11-23 10:54 ` Andi Kleen
2006-11-23 11:00 ` Benjamin Herrenschmidt
2006-11-23 11:00 ` Benjamin Herrenschmidt
2006-11-25 23:22 ` David Brownell
2006-11-25 23:22 ` David Brownell
2006-11-26 11:04 ` Joakim Tjernlund [this message]
2006-11-26 11:04 ` Joakim Tjernlund
2006-11-26 19:21 ` Alessandro Zummo
2006-11-26 19:21 ` Alessandro Zummo
2006-11-26 21:37 ` Joakim Tjernlund
2006-11-26 21:37 ` Joakim Tjernlund
2006-11-26 22:06 ` Michael Raskin
2006-11-26 22:53 ` Alessandro Zummo
2006-11-26 22:53 ` Alessandro Zummo
2006-11-27 1:21 ` [Bulk] " David Brownell
2006-11-27 1:21 ` David Brownell
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