Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 1 Jun 2023 13:53:08 -0400
From:   Kent Overstreet <kent.overstreet@linux.dev>
To:     Song Liu <song@kernel.org>
Cc:     linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        mcgrof@kernel.org, peterz@infradead.org, tglx@linutronix.de,
        x86@kernel.org, rppt@kernel.org
Subject: Re: [PATCH 0/3] Type aware module allocator
Message-ID: <ZHjbBAnpkfw2oBCr@moria.home.lan>
References: <20230526051529.3387103-1-song@kernel.org>
 <ZHGrjJ8PqAGN9OZK@moria.home.lan>
 <CAPhsuW4DAwx=7Nta5HGiPTJ1LQJCGJGY3FrsdKi62f_zJbsRFQ@mail.gmail.com>
 <ZHTuBdlhSI0mmQGE@moria.home.lan>
 <CAPhsuW6hqzLuNhvkHFOmKTJdQm8A0JdUna=1iFdRC0y+kKmF4Q@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CAPhsuW6hqzLuNhvkHFOmKTJdQm8A0JdUna=1iFdRC0y+kKmF4Q@mail.gmail.com>
Precedence: bulk

On Tue, May 30, 2023 at 03:48:51PM -0700, Song Liu wrote:
> On Mon, May 29, 2023 at 11:25 AM Kent Overstreet
> <kent.overstreet@linux.dev> wrote:
> >
> > On Sat, May 27, 2023 at 10:58:37PM -0700, Song Liu wrote:
> > > I don't think we are exposing architecture specific options to users.
> > > Some layer need to handle arch specifics. If the new allocator is
> > > built on top of module_alloc, module_alloc is handling that. If the new
> > > allocator is to replace module_alloc, it needs to handle arch specifics.
> >
> > Ok, I went back and read more thoroughly, I got this part wrong. The
> > actual interface is the mod_mem_type enum, not mod_alloc_params or
> > vmalloc_params.
> >
> > So this was my main complaint, but this actually looks ok now.
> >
> > It would be better to have those structs in a .c file, not the header
> > file - it looks like those are the public interface the way you have it.
> 
> Thanks for this suggestion. It makes a lot of sense. But I am not quite
> sure how we can avoid putting it in the header yet. I will take a closer
> look. OTOH, if we plan to use Mike's new allocator to replace vmalloc,
> we probably don't need this part.

The architectures previously exported constants that were used by
module_alloc(), why not stick with that?

> AFAICT, we don't have a global text_poke() API yet. I can take a look
> into it (if it makes sense).

Great

> Yeah, that's part of the goal to extend the scope from executable to all
> types.

Yeah it took me a bit to wrap my head around how this all makes sense -
it started out as just a better module_alloc(), then there was lots of
talk about hugepages.

I like it more now, looking forward to see how it fits together with
Mike's work :)