qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH v2] iov: avoid memcpy for "simple" iov_from_buf/


From: Stefan Hajnoczi
Subject: Re: [Qemu-devel] [PATCH v2] iov: avoid memcpy for "simple" iov_from_buf/iov_to_buf
Date: Wed, 23 Dec 2015 12:45:55 +0800
User-agent: Mutt/1.5.24 (2015-08-30)

On Tue, Dec 22, 2015 at 12:03:33PM +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 <address@hidden>
> ---
>         v1->v2: check for overflow in offset + bytes, which
>         is covered by test-iov
> 
>  include/qemu/iov.h | 34 ++++++++++++++++++++++++++++++----
>  util/iov.c         |  8 ++++----
>  2 files changed, 34 insertions(+), 8 deletions(-)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

Attachment: signature.asc
Description: PGP signature


reply via email to

[Prev in Thread] Current Thread [Next in Thread]