Re: [PATCH 3/3] virtio_ring: unify direct/indirect code paths.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sep 5, 2014 3:55 AM, "Paolo Bonzini" <pbonzini@xxxxxxxxxx> wrote:
>
> Il 03/09/2014 06:29, Rusty Russell ha scritto:
> > +     desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp);
> > +     if (!desc)
> > +             return NULL;
> >
> > -     return head;
> > +     for (i = 0; i < total_sg; i++)
> > +             desc[i].next = i+1;
> > +     return desc;
> >  }
>
> Would it make sense to keep a cache of a few (say) 8- or 16-element
> indirect descriptors?  You'd only have to do this ugly (and slowish) for
> loop on the first allocation.
>
> Also, since this is mostly an aesthetic patch,
>
> > +     if (indirect)
> > +             vq->free_head = vq->vring.desc[head].next;
> > +     else
> > +             vq->free_head = i;
>
> I'd move the indirect case above, where the vring.desc[head] is actually
> allocated.
>

Please don't: I'll just have to undo it for the DMA API stuff, since
descriptor setup will be able to fail.

--Andy
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization




[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux