From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jan Beulich <JBeulich@novell.com>,
Xiaowei Yang <xiaowei.yang@huawei.com>,
Nick Piggin <npiggin@kernel.dk>,
fanhenglong@huawei.com, Kaushik Barde <kbarde@huawei.com>,
Kenneth Lee <liguozhu@huawei.com>,
linqaingmin <linqiangmin@huawei.com>,
wangzhenguo@huawei.com, Wu Fengguang <fengguang.wu@intel.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
linux-kernel@vger.kernel.org,
Marcelo Tosatti <mtosatti@redhat.com>,
Avi Kivity <avi@redhat.com>
Subject: Re: One (possible) x86 get_user_pages bug
Date: Thu, 27 Jan 2011 20:27:56 +0100 [thread overview]
Message-ID: <1296156476.15234.246.camel@laptop> (raw)
In-Reply-To: <4D41B90D.5000305@goop.org>
On Thu, 2011-01-27 at 10:27 -0800, Jeremy Fitzhardinge wrote:
>
> So is there some way we can preserve the current scheme's benefits while
> making it a bit more general? (If anyone else has non-IPI-based
> shootdown, it would be s390; is there some inspiration there? An
> instruction perhaps?)
Well, you can provide a xen gupf implementation based on rcu freed
page-tables like powerpc, sparc and s390 have.
But you'll have to change the mmu_gather implementation of xen and use
the get_page_unless_zero() thing mentioned before (or use
page_cache_get_speculative()).
But I see no need to change the x86 implementation, if the architecture
ever changes the way it does tlb invalidation we need to change more
than just the gupf implementation.
next prev parent reply other threads:[~2011-01-27 19:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-27 13:05 Xiaowei Yang
2011-01-27 13:56 ` Peter Zijlstra
2011-01-27 14:30 ` Jan Beulich
2011-01-28 10:51 ` Peter Zijlstra
2011-01-27 14:49 ` Jan Beulich
2011-01-27 15:01 ` Peter Zijlstra
2011-01-27 18:27 ` Jeremy Fitzhardinge
2011-01-27 19:27 ` Peter Zijlstra [this message]
2011-01-30 13:01 ` Avi Kivity
2011-01-30 22:21 ` Kaushik Barde
2011-01-31 18:04 ` Jeremy Fitzhardinge
2011-01-31 20:10 ` Kaushik Barde
2011-01-31 22:10 ` Jeremy Fitzhardinge
2011-01-27 16:07 ` Jan Beulich
2011-01-27 16:25 ` Peter Zijlstra
2011-01-27 16:41 ` Jan Beulich
2011-01-27 16:56 ` Peter Zijlstra
2011-01-27 21:24 ` Nick Piggin
2011-01-28 7:17 ` Xiaowei Yang
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