From: Fabrice Bellard <fabrice@bellard.org>
To: Piotras <piotras@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Re: [PATCH] CONFIG_MMU_MAP powerpc host support
Date: Tue, 21 Dec 2004 00:11:06 +0100 [thread overview]
Message-ID: <41C75C0A.5070102@bellard.org> (raw)
In-Reply-To: <da63183704122013313371ce6@mail.gmail.com>
Piotras wrote:
> Great!
>
> Do you have an estimate of possible performance gain by introducing
> direct pointer to mmu_map for memory read?
>
> I have two ideas for future experimentation.
>
> There is a trick possible without wasting another register for global
> variable: use two copies of CPUState (one for privileged and another
> for user mode), then make mmu_map.add_read first member of the
> struct. This would introduce guest register coping for user/supervisor
> switch, but maybe performance gain would justify this.
> Another idea: if we could align add_read/add_write on 64k boundary,
> "addi" could be removed.
IMHO, using a single global register and interleaving the 4 access types
is the best solution...
Fabrice.
next prev parent reply other threads:[~2004-12-20 23:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-20 17:55 [Qemu-devel] [PATCH] CONFIG_MMU_MAP powerpc host support Magnus Damm
2004-12-20 21:31 ` [Qemu-devel] " Piotras
2004-12-20 22:12 ` Magnus Damm
2004-12-20 22:56 ` Daniel Serpell
2004-12-20 23:11 ` Fabrice Bellard [this message]
2004-12-25 0:04 ` [Qemu-devel] " Laurent Amon
2004-12-25 13:48 ` Norikatsu Shigemura
2004-12-27 16:06 ` Laurent Amon
2004-12-27 21:41 ` Pierre d'Herbemont
2004-12-27 23:43 ` Laurent Amon
2004-12-28 9:15 ` Daniel Egger
2004-12-28 9:55 ` Pierre d'Herbemont
2004-12-28 10:04 ` Daniel Egger
2004-12-28 11:18 ` Pierre d'Herbemont
2004-12-29 11:43 ` Piotras
2005-01-02 18:26 ` Daniel Egger
2005-01-02 20:18 ` Laurent Amon
2005-01-03 10:31 ` Daniel Egger
2005-01-03 12:08 ` Laurent Amon
2005-01-03 12:57 ` Daniel Egger
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