Subject: Re: [PATCH v5 7/8] execmem: add support for cache of large ROX pages

From: Mike Rapoport <[email-masked]>
Date: Thu, 10 Oct 2024 12:29:39 +0300

On Wed, Oct 09, 2024 at 01:24:27PM -0700, Andrew Morton wrote:
> On Wed,  9 Oct 2024 21:08:15 +0300 Mike Rapoport <[email-masked]> wrote:
> 
> > Using large pages to map text areas reduces iTLB pressure and improves
> > performance.
> 
> Are there any measurable performance improvements?

I don't have any numbers, I just followed the common sense of "less TLB
entries is better" and relied on Thomas comments from previous discussions.
 
> What are the effects of this series upon overall memory consumption?
 
There will be some execmem cache fragmentation and an increase in memory
consumption. It depends on the actual modules loaded and how large it the
fragmentation.

For a set of pretty randomly chosen modules where most come from
net/netfilter I see an increase from 19M to 25M.

> The lack of acks is a bit surprising for a v5 patch, but I'll add all
> this to mm.git for some testing, thanks.
> 

-- 
Sincerely yours,
Mike.