Re: [Xen-devel] [PATCH][2/17] USB virt 2.6 split driver---xenidc buffer resource provider

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

On 22 Nov 2005, at 10:55, Muli Ben-Yehuda wrote:

> > I don't understand this.  I thought vmalloc was more likely to be
> > successful than kmalloc because the memory doesn't need to be 
> > contiguous
> > so I thought it was preferable to use vmalloc when possible.
> Nope, vmalloc has both a resource usage issue (we only have a limited
> vmalloc space) and some small overhead that kmalloc doesn't. The only
> time you should use vmalloc is if you know that kmalloc can't give you
> a large enough buffer.
If the buffer is > PAGE_SIZE, you should use vmalloc if at all 
possible. Order != 0 allocations can easily fail on a churned box with 
lots of memory fragmentation.
 -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel