From: Julien Grall <julien.grall@arm.com>
To: Baodong Chen <chenbaodong@mxnavi.com>, xen-devel@lists.xenproject.org
Cc: Stefano Stabellini <sstabellini@kernel.org>
Subject: Re: [Xen-devel] [PATCH] xen/arm: io: add function swap_mmio_handler()
Date: Wed, 12 Jun 2019 10:08:26 +0100 [thread overview]
Message-ID: <af3fe48d-afaa-3184-e142-9a1e2b8574f4@arm.com> (raw)
In-Reply-To: <1560318154-19095-1-git-send-email-chenbaodong@mxnavi.com>
Hi,
On 6/12/19 6:42 AM, Baodong Chen wrote:
> Swap function can be used when calling sort().
> or else, the default swap function generic_swap() is used,
> which is a little inefficient.
I am not entirely convince this will be more efficient. mmio_handler
does not fit in 64 bit, so the compiler may decide to do either multiple
load or replace with a memcpy.
So at best this feels some micro-optimization. But then, this is only
call a limited number of time at each domain build. Is it really worth it?
On a side note, I have noticed you are sending a lot of
optimization/clean-up patch. What is your end goal here?
If it is to improve the performance, then there are much bigger fish to
fry within Xen code base. I am happy to point some of them based on
where you are looking to improve.
Cheers,
--
Julien Grall
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next prev parent reply other threads:[~2019-06-12 9:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 5:42 [Xen-devel] [PATCH] xen/arm: io: add function swap_mmio_handler() Baodong Chen
2019-06-12 9:08 ` Julien Grall [this message]
2019-06-12 10:08 ` chenbaodong
2019-06-12 12:21 ` Julien Grall
2019-06-13 0:31 ` chenbaodong
2019-06-24 18:18 ` Stefano Stabellini
2019-06-24 18:27 ` Stefano Stabellini
2019-06-24 19:27 ` Julien Grall
2019-06-24 20:17 ` Stefano Stabellini
2019-06-24 21:18 ` Julien Grall
2019-06-24 23:59 ` Stefano Stabellini
2019-06-25 8:46 ` Julien Grall
2019-06-27 23:30 ` chenbaodong
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