Messages in this thread | | | Date | Mon, 01 Aug 2011 13:46:33 +0800 | From | Liu Yuan <> | Subject | Re: [RFC PATCH]vhost-blk: In-kernel accelerator for virtio block device |
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On 07/30/2011 02:12 AM, Badari Pulavarty wrote: > Hi Liu Yuan, > > I am glad to see that you started looking at vhost-blk. I did an > attempt year ago to improve block > performance using vhost-blk approach. > > http://lwn.net/Articles/379864/ > http://lwn.net/Articles/382543/ > > I will take a closer look at your patchset to find differences and > similarities. > > - I focused on using vfs interfaces in the kernel, so that I can use > it for file-backed devices. > Our use-case scenario is mostly file-backed images. > vhost-blk's that uses Linux AIO also support file-backed images. Actually, I have run Guests both on raw partition and raw file images.
> - In few cases, virtio-blk did outperform vhost-blk -- which was > counter intuitive - but > couldn't exactly nail down. why ? > > - I had to implement my own threads for parellism. I see that you are > using aio infrastructure > to get around it. > > - In our high scale performance testing, what we found is block-backed > device performance is > pretty close to bare-metal (91% of bare-metal). vhost-blk didn't add > any major benefits to it. > I am curious on your performance analysis & data on where you see the > gains and why ? > Possibly bypass vfs-layer and translate sg lists from virtio buffer into BIOs would benefit the block-backed device. I'll give it a try later.
> Hence I prioritized my work low :( > > Now that you are interested in driving this, I am happy to work with > you and see what > vhost-blk brings to the tables. (even if helps us improve virtio-blk). > > Thanks, > Badari > >
That's great.
Yuan
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