From: "Jan Beulich" <JBeulich@novell.com>
To: Dulloor <dulloor@gmail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>,
xen-devel@lists.xensource.com,
Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: Re: Even faster page copy for Xen?
Date: Tue, 10 Aug 2010 07:24:13 +0100 [thread overview]
Message-ID: <4C610CAD020000780000EF6A@vpn.id2.novell.com> (raw)
In-Reply-To: <AANLkTikdcBe1FrwLy-+7qfyWOfJ4GD1zqSPSdo6VwN=i@mail.gmail.com>
>>> On 09.08.10 at 19:57, Dulloor <dulloor@gmail.com> wrote:
> On Mon, Aug 9, 2010 at 10:47 AM, Dulloor <dulloor@gmail.com> wrote:
>> On Fri, Aug 6, 2010 at 12:57 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>> I'm not sure how much of this applies to the much more specific
>>> case of copying pages... Additionally, I don't think trying to
>>> use XMM registers in Xen would be a good idea.
>
>> Why would you say using xmm/sse in Xen is a bad idea ? We already have a
>> copy_page_sse2 (in copy_page.S) in our code base and available (by default)
>> for x86_64. Is it a bad idea to use that ?
>
> Never mind about copy_page_sse2 ! That function name is misleading.
Why - it is code that's dependent on SSE2 to be available. Note it
doesn't have 'xmm' in its name - that indeed would be misleading.
> But, still ... I need a copy_page routine and was planning to use sse.
> Is that not fine ?
You can do so if you feel like saving/restoring all necessary XMM
state isn't going to eat up all of the performance win...
Jan
next prev parent reply other threads:[~2010-08-10 6:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-15 18:15 Even faster page copy for Xen? Dan Magenheimer
2010-07-15 21:35 ` Keir Fraser
2010-07-15 23:36 ` Dan Magenheimer
2010-07-16 7:57 ` Keir Fraser
2010-08-06 7:57 ` Jan Beulich
2010-08-09 17:47 ` Dulloor
2010-08-09 17:57 ` Dulloor
2010-08-10 6:24 ` Jan Beulich [this message]
2010-08-10 12:31 ` Dan Magenheimer
2010-08-10 12:41 ` Keir Fraser
2010-08-10 12:46 ` Jan Beulich
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