Messages in this thread | | | Subject | Re: copy_from_user / copy_to_user with no swap space | Date | Tue, 17 Oct 2006 07:58:30 -0300 | From | "Horst H. von Brand" <> |
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mfbaustx <mfbaustx@gmail.com> wrote: > >>> No. Your code may be only partially paged into RAM. > >>> The same can happen for any mmaped data.
> That's what I thought I read. But then my question is: with > on-demand paging, is it possible to have two processes partially > paged?
Why shouldn't they be? The whole idea is having just /parts/ (hopefully the ones in active use) in memory.
> Surely, it MUST be the case that any processes with > overlapping logical address spaces must be paged coherently.
I don't know what this is supposed to mean...
> So, > while on-demand "paging-in" allows for partial paging of a process, > is it the case that, on a context switch, the user-space PTE's are > completely erased (so that you get page-faults and can then on-demand > page them in...)?
Each process has its own page tables, they don't get in each others hair. And the page tables precisely manage making several processes get access to the /same/ logical addresses, but at /different/ physical addresses. -- Dr. Horst H. von Brand User #22616 counter.li.org Departamento de Informatica Fono: +56 32 2654431 Universidad Tecnica Federico Santa Maria +56 32 2654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 2797513 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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