Am Freitag, 13. Juni 2003 23:47 schrieb Dave Hansen:

quoted

When you have lots of tasks, the pagetables start taking up lots of
lowmem.  We have the ability to push the PTE pages into highmem, but
that exacts a penalty from the atomic kmaps which, depending on
workload, can be a 10-15% performance hit.
The following patches implement something which we like to call UKVA.
It's a Kernel Virtual Area which is private to a process, just like
Userspace.  You can put any process-local data that you want in the
area.  But, for now, I just put PTE pages in there.

On Sat, Jun 14, 2003 at 01:27:48PM +0200, Oliver Neukum wrote:

If you put only such pages there, do you really want that memory to
be per task? IMHO it should be per memory context to aid threading
performance.

Per-process is essentially per-mm.


On Sat, Jun 14, 2003 at 01:27:48PM +0200, Oliver Neukum wrote:

Secondly, doesn't this scream for using large pages?

No, 2MB/4MB pages are not useful here.


-- wli
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