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Date:   Mon, 29 May 2023 14:25:09 -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
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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.

> > The memory protection interface also needs to go, we've got a better
> > interface to model after (text_poke(), although that code needs work
> > too!). And the instruction fill features need a thorough justification
> > if they're to be included.
> 
> I guess the first step to use text_poke() is to make it available on all
> archs? That doesn't seem easy to me.

We just need a helper that either calls text_poke() or does the page
permission dance in a single place.

If we do the same thing for other mod_mem_types, we could potentially
allow them to be shared on hugepages too.