Re: kmalloc() allocation.

[Jeff Garzik <jgarzik@mandrakesoft.com>]

"Richard B. Johnson" wrote:
> 
> On Mon, 30 Oct 2000, Jeff Garzik wrote:
> 
> > "Richard B. Johnson" wrote:
> > > Now, I could set up a linked-list of buffers and use vmalloc()
> > > if the buffers were allocated from non-paged RAM. I don't think
> > > they are. These buffers must be present during an interrupt.
> >
> > Non-paged RAM?  I'm not sure what you mean by that.
> >
> > Both kmalloc and vmalloc allocate pages, but neither will allocate pages
> > that the system will swap out (page out).  [vk]malloc pages are always
> > around during an interrupt.
> >
> >       Jeff
> 
> Hmm, vmalloc() doesn't seem to have the size limitation. Are you sure
> that it's present during an interrupt? I can't page-fault during the
> interrupt.

vmalloc'd memory does have a size limitation, though it's larger than
kmalloc's limit.  AFAIK vmalloc'd memory is a collection of pages
remapping in the page tables to be virtually contiguous, implying that
it is present during an interrupt.

-- 
Jeff Garzik             | "Mind if I drive?"  -Sam
Building 1024           | "Not if you don't mind me clawing at the
MandrakeSoft            |  dash and shrieking like a cheerleader."
                        |                     -Max
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