From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: Word-at-a-time dcache name accesses
Date: Sat, 03 Mar 2012 10:47:43 -0800 [thread overview]
Message-ID: <4F52674F.3010508@zytor.com> (raw)
In-Reply-To: <m2eht964ud.fsf@firstfloor.org>
On 03/03/2012 08:12 AM, Andi Kleen wrote:
> "H. Peter Anvin" <hpa@zytor.com> writes:
>
>> On 03/02/2012 03:46 PM, Linus Torvalds wrote:
>>>
>>> Comments?
>>>
>>
>> My biggest concern is what happens when this happens to be at the end of
>> mapped kernel memory and we overrun the page?
>
> A long time ago (AMD K7ish) we had hardware bugs to work around in
> this area. Overlapping into some PCI hole MMIO areas could cause obscure
> hangs. That is why I was always careful to not do that in any x86
> library code.
>
We still map too much, though. That's a separate problems which should
be fixed in its own right, though.
-hpa
next prev parent reply other threads:[~2012-03-03 18:47 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-02 23:46 Word-at-a-time dcache name accesses (was Re: .. anybody know of any filesystems that depend on the exact VFS 'namehash' implementation?) Linus Torvalds
2012-03-03 0:02 ` Ted Ts'o
2012-03-03 0:17 ` david
2012-03-03 0:24 ` Linus Torvalds
2012-03-04 22:19 ` Matthew Wilcox
2012-03-04 23:27 ` Linus Torvalds
2012-03-03 0:17 ` Linus Torvalds
2012-03-03 0:38 ` H. Peter Anvin
2012-03-03 0:57 ` Linus Torvalds
2012-03-03 1:02 ` H. Peter Anvin
2012-03-03 1:11 ` Linus Torvalds
2012-03-03 1:17 ` H. Peter Anvin
2012-03-03 16:12 ` Word-at-a-time dcache name accesses Andi Kleen
2012-03-03 18:47 ` H. Peter Anvin [this message]
2012-03-03 20:10 ` Word-at-a-time dcache name accesses (was Re: .. anybody know of any filesystems that depend on the exact VFS 'namehash' implementation?) Linus Torvalds
2012-03-04 2:27 ` Word-at-a-time dcache name accesses (was Re: .. anybody know ofany " Tetsuo Handa
2012-03-04 4:31 ` Andi Kleen
2012-03-05 3:58 ` Word-at-a-time dcache name accesses (was Re: .. anybody know of any " Jason Garrett-Glaser
2012-03-05 5:38 ` Linus Torvalds
2012-03-27 4:42 ` Brian Gerst
2012-03-27 4:42 ` Brian Gerst
2012-03-27 5:02 ` Dave Jones
2012-03-27 5:31 ` Brian Gerst
2012-03-28 0:39 ` Linus Torvalds
2012-03-28 0:39 ` Linus Torvalds
2012-03-28 0:50 ` Linus Torvalds
2012-03-28 0:50 ` Linus Torvalds
2012-03-28 0:56 ` Brian Gerst
[not found] ` <CACvQF53YasSCUit2KoWDimgObknCz++aU90MesSfvAZTeUFQHw@mail.gmail.com>
2013-04-04 16:50 ` Lai Jiangshan
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