From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@qumranet.com>
Subject: [ofa-general] Re: [PATCH] mmu notifiers #v8
Date: Mon, 03 Mar 2008 20:09:49 +0200
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Cc: Nick Piggin <npiggin@suse.de>, Andrea Arcangeli <andrea@qumranet.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-mm@kvack.org,
	Izik Eidus <izike@qumranet.com>, Kanoj Sarcar <kanojsarcar@yahoo.com>,
	Roland Dreier <rdreier@cisco.com>, linux-kernel@vger.kernel.org,
	kvm-devel@lists.sourceforge.net, daniel.blueman@quadrics.com,
	Robin Holt <holt@sgi.com>, general@lists.openfabrics.org,
	akpm@linux-foundation.org, Christoph Lameter <clameter@sgi.com>
To: Jack Steiner <steiner@sgi.com>
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Jack Steiner wrote:
> The range invalidates have a performance advantage for the GRU. TLB invalidates
> on the GRU are relatively slow (usec) and interfere somewhat with the performance
> of other active GRU instructions. Invalidating a large chunk of addresses with
> a single GRU TLBINVAL operation is must faster than issuing a stream of single
> page TLBINVALs.
>
> I expect this performance advantage will also apply to other users of mmuops.
>   

In theory this would apply to kvm as well (coalesce tlb flush IPIs, 
lookup shadow page table once), but is it really a fast path?  What 
triggers range operations for your use cases?

-- 
error compiling committee.c: too many arguments to function