From: Stefan Hajnoczi <stefanha@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: mjt@tls.msk.ru, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] iov: avoid memcpy for "simple" iov_from_buf/iov_to_buf
Date: Fri, 18 Dec 2015 13:08:43 +0800 [thread overview]
Message-ID: <20151218050843.GA13945@stefanha-x1.localdomain> (raw)
In-Reply-To: <1450263453-2589-1-git-send-email-pbonzini@redhat.com>
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On Wed, Dec 16, 2015 at 11:57:33AM +0100, Paolo Bonzini wrote:
> memcpy can take a large amount of time for small reads and writes.
> For virtio it is a common case that the first iovec can satisfy the
> whole read or write. In that case, and if bytes is a constant to
> avoid excessive growth of code, inline the first iteration
> into the caller.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> include/qemu/iov.h | 32 ++++++++++++++++++++++++++++----
> util/iov.c | 8 ++++----
> 2 files changed, 32 insertions(+), 8 deletions(-)
Thanks, applied to my block-next tree:
https://github.com/stefanha/qemu/commits/block-next
Stefan
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next prev parent reply other threads:[~2015-12-18 6:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-16 10:57 [Qemu-devel] [PATCH] iov: avoid memcpy for "simple" iov_from_buf/iov_to_buf Paolo Bonzini
2015-12-18 5:08 ` Stefan Hajnoczi [this message]
2015-12-22 8:34 ` Stefan Hajnoczi
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