From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
Anthony Liguori <aliguori@us.ibm.com>,
dkoch@cloudswitch.com, qemu-devel@nongnu.org,
Michael Roth <mdroth@linux.vnet.ibm.com>,
Blue Swirl <blauwirbel@gmail.com>,
khoa@us.ibm.com, Stefan Hajnoczi <stefanha@redhat.com>,
Asias He <asias@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v3 09/12] iov: add iov_get_ptr() to reference vector data
Date: Thu, 22 Nov 2012 10:52:27 +0100 [thread overview]
Message-ID: <50ADF5DB.7060201@redhat.com> (raw)
In-Reply-To: <20121122094507.GA24617@redhat.com>
Il 22/11/2012 10:45, Michael S. Tsirkin ha scritto:
> All this looks suspiciously like premature optimization to me.
> Do we have data to show avoiding header copy is a win?
The code is a little simpler, because we know the footer is 1 byte only.
Paolo
> The caller would have to handle the case where the header is not
> contigious, which seems just too complex - in practice the code
> seems to simply fail in this case.
>
> Why not just copy the header using iov_from_buf()/iov_to_buf()
> and be done with it?
next prev parent reply other threads:[~2012-11-22 9:52 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-21 18:32 [Qemu-devel] [PATCH v3 00/12] virtio: virtio-blk data plane Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 01/12] raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 02/12] configure: add CONFIG_VIRTIO_BLK_DATA_PLANE Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 03/12] dataplane: add host memory mapping code Stefan Hajnoczi
2012-11-26 14:46 ` Don Koch
2012-11-26 15:36 ` Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 04/12] dataplane: add virtqueue vring code Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 05/12] dataplane: add event loop Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 06/12] dataplane: add Linux AIO request queue Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 07/12] iov: add iov_discard() to remove data Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 08/12] test-iov: add iov_discard() testcase Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 09/12] iov: add iov_get_ptr() to reference vector data Stefan Hajnoczi
2012-11-22 9:34 ` Paolo Bonzini
2012-11-22 9:45 ` Michael S. Tsirkin
2012-11-22 9:52 ` Paolo Bonzini [this message]
2012-11-22 10:38 ` Michael S. Tsirkin
2012-11-22 10:54 ` Paolo Bonzini
2012-11-22 11:14 ` Michael S. Tsirkin
2012-11-22 11:58 ` Stefan Hajnoczi
2012-11-22 12:15 ` Paolo Bonzini
2012-11-22 12:35 ` Michael S. Tsirkin
2012-11-22 15:18 ` Stefan Hajnoczi
2012-11-21 18:32 ` [Qemu-devel] [PATCH v3 10/12] test-iov: add iov_get_ptr() test case Stefan Hajnoczi
2012-11-21 18:33 ` [Qemu-devel] [PATCH v3 11/12] dataplane: add virtio-blk data plane code Stefan Hajnoczi
2012-11-21 18:33 ` [Qemu-devel] [PATCH v3 12/12] virtio-blk: add x-data-plane=on|off performance feature Stefan Hajnoczi
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