From: Jason Wang <jasowang@redhat.com>
To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
virtualization@lists.linux-foundation.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH 2/6] virtio: split: alloc indirect desc with extra
Date: Mon, 10 Jan 2022 14:43:39 +0800 [thread overview]
Message-ID: <c649faa9-aa1f-e5ff-a448-0abce38eeff9@redhat.com> (raw)
In-Reply-To: <20220107063306.23240-3-xuanzhuo@linux.alibaba.com>
在 2022/1/7 下午2:33, Xuan Zhuo 写道:
> In the scenario where indirect is not used, each desc corresponds to an
> extra, which is used to record information such as dma, flags, and
> next.
>
> In the scenario of using indirect, the assigned desc does not have the
> corresponding extra record dma information, and the dma information must
> be obtained from the desc when unmap.
>
> This patch allocates the corresponding extra array when indirect desc is
> allocated. This has these advantages:
> 1. Record the dma information of desc, no need to read desc when unmap
> 2. It will be more convenient and unified in processing
> 3. Some additional information can be recorded in extra, which will be
> used in subsequent patches.
Two questions:
1) Is there any performance number for this change? I guess it gives
more stress on the cache.
2) Is there a requirement to mix the pre mapped sg with unmapped sg? If
not, a per virtqueue flag looks sufficient
Thanks
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2022-01-10 6:43 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-07 6:33 [PATCH 0/6] virtio: support advance DMA Xuan Zhuo
2022-01-07 6:33 ` [PATCH 1/6] virtio: rename vring_unmap_state_packed() to vring_unmap_extra_packed() Xuan Zhuo
2022-01-10 6:19 ` Jason Wang
2022-01-07 6:33 ` [PATCH 2/6] virtio: split: alloc indirect desc with extra Xuan Zhuo
2022-01-10 6:43 ` Jason Wang [this message]
2022-01-10 7:19 ` Xuan Zhuo
2022-01-10 7:41 ` Jason Wang
2022-01-10 7:52 ` Xuan Zhuo
2022-01-10 8:54 ` Jason Wang
2022-01-10 9:23 ` Xuan Zhuo
2022-01-10 9:49 ` Michael S. Tsirkin
2022-01-10 9:58 ` Xuan Zhuo
2022-01-10 10:06 ` Michael S. Tsirkin
2022-01-11 2:44 ` Jason Wang
2022-01-11 5:57 ` Xuan Zhuo
2022-01-07 6:33 ` [PATCH 3/6] virtio: packed: " Xuan Zhuo
2022-01-07 6:33 ` [PATCH 4/6] virtio: split: virtqueue_add_split() support dma address Xuan Zhuo
2022-01-10 6:45 ` Jason Wang
2022-01-10 7:24 ` Xuan Zhuo
2022-01-07 6:33 ` [PATCH 5/6] virtio: packed: virtqueue_add_packed() " Xuan Zhuo
2022-01-07 6:33 ` [PATCH 6/6] virtio: add api virtio_dma_map() for advance dma Xuan Zhuo
2022-01-10 7:12 ` Michael S. Tsirkin
2022-01-10 7:24 ` Xuan Zhuo
2022-01-10 9:59 ` [PATCH 0/6] virtio: support advance DMA Michael S. Tsirkin
2022-01-11 2:54 ` Jason Wang
2022-01-11 6:17 ` Xuan Zhuo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c649faa9-aa1f-e5ff-a448-0abce38eeff9@redhat.com \
--to=jasowang@redhat.com \
--cc=mst@redhat.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=xuanzhuo@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).