From: Nick Piggin <npiggin@kernel.dk>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Nick Piggin <npiggin@kernel.dk>,
"Xen-devel@lists.xensource.com" <Xen-devel@lists.xensource.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Could we do immediate pte zaps in vunmap?
Date: Sat, 27 Nov 2010 21:36:56 +1100 [thread overview]
Message-ID: <20101127103656.GA6884@amd> (raw)
In-Reply-To: <4CEF6B8B.8080206@goop.org>
On Fri, Nov 26, 2010 at 12:10:51AM -0800, Jeremy Fitzhardinge wrote:
> What if vm_unmap_ram() and co. immediately zeroed out the ptes, but
> lazily deferred the tlb flushes? It seems to me there's no benefit in
> batching up the pte clearing since that can't be amortized like the tlb
> flush.
Yes that can be done.
> I think that would solve the problem we have with the interactions
> between lazy unmap and Xen. The issue is having stray pte entries
> around (because Xen keeps track of those as part of its page-type
> mechanism), but stale tlb entries are no problem.
It would be great if that solves it.
next prev parent reply other threads:[~2010-11-27 10:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-26 8:10 Could we do immediate pte zaps in vunmap? Jeremy Fitzhardinge
2010-11-27 10:36 ` Nick Piggin [this message]
2010-11-29 20:32 ` [PATCH RFC] vmalloc: eagerly clear ptes on vunmap Jeremy Fitzhardinge
2010-11-30 12:42 ` Nick Piggin
2010-11-30 17:45 ` Jeremy Fitzhardinge
2010-12-01 0:29 ` Andrew Morton
2010-12-01 3:09 ` Jeremy Fitzhardinge
2010-12-01 3:23 ` Andrew Morton
2010-12-01 8:16 ` Jeremy Fitzhardinge
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