From: "H. Peter Anvin" <hpa@zytor.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [git pull] x86 PAT changes
Date: Fri, 25 Apr 2008 17:06:12 -0700 [thread overview]
Message-ID: <481271F4.7060401@zytor.com> (raw)
In-Reply-To: <alpine.LFD.1.10.0804251351511.2779@woody.linux-foundation.org>
Linus Torvalds wrote:
>
> So why is PAT dependent on NONPROMISC_DEVMEM here?
>
> It seems pointless and wrong. Somebody might want to have both the full
> /dev/mem and PAT.
>
The problem is that that can create cached/uncached aliases, which can
cause some processors to lock up (especially AMD is known to have a lot
of errata in this area.)
-hpa
next prev parent reply other threads:[~2008-04-26 0:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-24 22:56 [git pull] x86 PAT changes Ingo Molnar
2008-04-25 23:43 ` Linus Torvalds
2008-04-26 0:06 ` H. Peter Anvin [this message]
2008-04-26 1:12 ` Linus Torvalds
2008-04-26 8:56 ` Ingo Molnar
2008-04-26 16:54 ` Pallipadi, Venkatesh
2008-04-26 17:15 ` Linus Torvalds
2008-04-26 18:32 ` Venki Pallipadi
2008-04-26 19:07 ` [patch] x86, PAT: disable /dev/mem mmap RAM with PAT Ingo Molnar
2008-04-26 9:57 ` [git pull] x86 PAT changes Ingo Molnar
2008-04-26 13:40 ` Gabriel C
2008-04-26 14:42 ` Ingo Molnar
2008-04-26 15:37 ` Gabriel C
2008-04-26 15:41 ` Ingo Molnar
2008-04-26 16:43 ` Linus Torvalds
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