From: Karel Zak <kzak@redhat.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Ingo Molnar <mingo@elte.hu>
Subject: Re: [kerneloops] regression in 2.6.27 wrt "lock_page" and the "hwclock" program
Date: Tue, 14 Oct 2008 23:04:04 +0200 [thread overview]
Message-ID: <20081014210404.GJ10429@nb.net.home> (raw)
In-Reply-To: <20081013105559.15ccb67f@infradead.org>
On Mon, Oct 13, 2008 at 10:55:59AM -0400, Arjan van de Ven wrote:
> Karel: Can you describe what it WANTS to do so we can see if we can
It wants to "atomically" (without context switch) read/write time
from CMOS. This is unrealistic of course.
> just extend the linux kernel to do that the right way?
The kernel is already extended and hwclock uses the extension :-)
The solution is /dev/rtc.
The code that directly works with CMOS is fallback solution for
people who don't want or can not use the standard RTC device. I guess
people use this functionally for experiments only. Today the RTC
framework should work everywhere.
I'll simply remove the "cli" / "sti" code -- eventually I can try
to optimize it by mlockall() and SCHED_FIFO (as suggested by Linus).
Karel
--
Karel Zak <kzak@redhat.com>
next prev parent reply other threads:[~2008-10-14 21:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-05 0:44 [kerneloops] regression in 2.6.27 wrt "lock_page" and the "hwclock" program Arjan van de Ven
2008-10-05 4:52 ` Andrew Morton
2008-10-05 15:11 ` Arjan van de Ven
2008-10-05 17:27 ` Andrew Morton
2008-10-05 17:38 ` Arjan van de Ven
2008-10-12 20:00 ` Karel Zak
2008-10-12 20:16 ` Linus Torvalds
2008-10-13 14:55 ` Arjan van de Ven
2008-10-14 21:04 ` Karel Zak [this message]
2008-10-13 15:26 ` Ingo Molnar
2008-10-13 15:40 ` Alan Cox
2008-10-13 15:44 ` Linus Torvalds
2008-10-13 16:02 ` Ingo Molnar
2008-10-13 16:08 ` Linus Torvalds
2008-10-13 16:21 ` Ingo Molnar
2008-10-12 19:46 ` Karel Zak
2008-10-05 18:18 ` Linus Torvalds
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