Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

From: Michael S. Tsirkin
Date: Tue Apr 06 2010 - 03:53:27 EST

On Tue, Apr 06, 2010 at 01:41:37PM +0800, Xin, Xiaohui wrote:
> Michael,
> >>
> >>For the DOS issue, I'm not sure how much the limit get_user_pages()
> >> can pin is reasonable, should we compute the bindwidth to make it?
> >There's a ulimit for locked memory. Can we use this, decreasing
> >the value for rlimit array? We can do this when backend is
> >enabled and re-increment when backend is disabled.
> I have tried it with rlim[RLIMIT_MEMLOCK].rlim_cur, but I found
> the initial value for it is 0x10000, after right shift PAGE_SHIFT,
> it's only 16 pages we can lock then, it seems too small, since the
> guest virito-net driver may submit a lot requests one time.
> Thanks
> Xiaohui

Yes, that's the default, but system administrator can always increase
this value with ulimit if necessary.

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