From: Andrea Arcangeli <aarcange@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mel@csn.ul.ie>, r6144 <rainy6144@gmail.com>,
linux-kernel@vger.kernel.org, Darren Hart <dvhltc@us.ibm.com>,
tglx <tglx@linutronix.de>,
Lee Schermerhorn <lee.schermerhorn@hp.com>
Subject: Re: Process-shared futexes on hugepages puts the kernel in an infinite loop in 2.6.32.11; is this fixed now?
Date: Mon, 19 Apr 2010 18:32:17 +0200 [thread overview]
Message-ID: <20100419163217.GB32034@random.random> (raw)
In-Reply-To: <1271693928.1676.18.camel@laptop>
On Mon, Apr 19, 2010 at 06:18:48PM +0200, Peter Zijlstra wrote:
> Well, most poison values have that problem and still we have them. Also
That would better be fixed too to stay <4096 for higher chance of
bug-detection, it doesn't make this case correct ;).
> on 64bit machines you can use POISON_POINTER_DELTA to map it outside the
> virtual address range.
We've thousands of magic values there, I don't see much benefit from
POISON_POINTER_DELTA other than being able to call it
0xdeadbeef+POISON_POINTER_DELTA ;). We always look the assembly to
find the actual real raw pointer value (without the field offset) so I
think using a range between 0xaaa and 0xbbb for the error pointers, is
functional enough, but it's up to you as long as it is a address range
that can't be used by userland it's surely ok ;).
next prev parent reply other threads:[~2010-04-19 17:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-16 15:45 Process-shared futexes on hugepages puts the kernel in an infinite loop in 2.6.32.11; is this fixed now? r6144
2010-04-16 20:27 ` Peter Zijlstra
2010-04-19 11:43 ` Mel Gorman
2010-04-19 11:52 ` Peter Zijlstra
2010-04-19 15:32 ` Mel Gorman
2010-04-19 15:45 ` Peter Zijlstra
2010-04-19 16:11 ` Andrea Arcangeli
2010-04-19 16:18 ` Peter Zijlstra
2010-04-19 16:32 ` Andrea Arcangeli [this message]
2010-04-19 16:34 ` Mel Gorman
2010-04-19 15:48 ` Andrea Arcangeli
2010-04-19 16:04 ` Darren Hart
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