Re: [PATCH v2 0/4] huge vmalloc mappings

From: Nicholas Piggin
Date: Tue Apr 14 2020 - 08:24:57 EST


Excerpts from David Rientjes's message of April 14, 2020 10:27 am:
> On Mon, 13 Apr 2020, Nicholas Piggin wrote:
>
>> We can get a significant win with larger mappings for some of the big
>> global hashes.
>>
>> Since RFC, relevant architectures have added p?d_leaf accessors so no
>> real arch changes required, and I changed it not to allocate huge
>> mappings for modules and a bunch of other fixes.
>>
>
> Hi Nicholas,
>
> Any performance numbers to share besides the git diff in the last patch in
> the series? I'm wondering if anything from mmtests or lkp-tests makes
> sense to try?

Hey, no I don't have any other tests I've run. Some of the networking
hashes do make use of it as well though, and might see a few % in
the right kind of workload. There's probably a bunch of other stuff
where it could help a little bit, looking through the tree, I just don't
have anything specific.

Thanks,
Nick