Re: [PATCH 01/11] x86/mm/pat: Don't free PGD entries on memory unmap

Andy Lutomirski
2015-09-22T18:03:48Z

On Tue, Sep 22, 2015 at 10:41 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Mon, Sep 21, 2015 at 11:23 PM, Ingo Molnar <mingo@kernel.org> wrote:
>>
>> This complicates PGD management, so don't do this. We can keep the
>> PGD mapped and the PUD table all clear - it's only a single 4K page
>> per 512 GB of memory mapped.
>
> I'm ok with this just from a "it removes code" standpoint. That said,
> some of the other patches here make me go "hmm". I'll answer them
> separately.
>

If we want to get rid of vmalloc faults, then this patch makes it much
more obvious that it can be done without hurting performance.

> Linus

--
Andy Lutomirski
AMA Capital Management, LLC