Re: Creating a per-task kernel space for kmap, user pagetables, et al

Andrea Arcangeli
2002-03-20T20:26:57Z

On Wed, Mar 20, 2002 at 04:36:48PM -0300, Rik van Riel wrote:
> On Wed, 20 Mar 2002, Martin J. Bligh wrote:
>
> > This, unfortunately, isn't a total solution - we may sometimes need to
> > modify the task's pagetables from outside the process context, eg.
> > swapout (thanks to dmc for pointing this out to me ;-)). For this, we'd
> > just use the existing kmap mechanism to create another mapping to use
> > temporarily, and we're no worse off than before. But on the whole I
> > think it wins us enough to be worthwhile.
>
> There is absolutely no problem mapping the page tables of
> another process into our own kmap space. It's just like

I thought he's talking about kswapd and friends, they all should keep
using the atomic kmaps for that, no problem there because we'll never
run copy-users from kswapd, kswapd doesn't have userspace to copy to :).

Andrea