Re: [PATCH v20 4/7] virtio-balloon: VIRTIO_BALLOON_F_SG

From: Tetsuo Handa
Date: Wed Jan 03 2018 - 05:19:08 EST


Wei Wang wrote:
> On 01/03/2018 10:29 AM, Tetsuo Handa wrote:
> > Matthew Wilcox wrote:
> >> The radix tree convention is objectively awful, which is why I'm working
> >> to change it. Specifying the GFP flags at radix tree initialisation time
> >> rather than allocation time leads to all kinds of confusion. The preload
> >> API is a pretty awful workaround, and it will go away once the XArray
> >> is working correctly. That said, there's no alternative to it without
> >> making XBitmap depend on XArray, and I don't want to hold you up there.
> >> So there's an xb_preload for the moment.
> > I'm ready to propose cvbmp shown below as an alternative to xbitmap (but
> > specialized for virtio-balloon case). Wei, can you do some benchmarking
> > between xbitmap and cvbmp?
> > ----------------------------------------
> > cvbmp: clustered values bitmap
>
> I don't think we need to replace xbitmap, at least at this stage. The
> new implementation doesn't look simpler at all, and virtio-balloon has
> worked well with xbitmap.
>
> I would suggest you to send out the new implementation for discussion
> after this series ends, and justify with better performance results if
> you could get.

I'm VMware Workstation Player user, and I don't have environment for doing
performance test using virtio-balloon. Thus, I need to ask you.

Also, please look at
http://lkml.kernel.org/r/1514904621-39186-1-git-send-email-penguin-kernel@xxxxxxxxxxxxxxxxxxx .