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From:   Song Liu <song@kernel.org>
Date:   Thu, 14 Apr 2022 14:03:17 -0700
Message-ID: <CAPhsuW42Dn2y9skhdJAK1fp9CFA06tpzG=6gMxeTobBj6xifPg@mail.gmail.com>
Subject: Re: [PATCH v3 bpf RESEND 3/4] module: introduce module_alloc_huge
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     bpf <bpf@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
        open list <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Kernel Team <kernel-team@fb.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
        Christoph Hellwig <hch@infradead.org>, imbrenda@linux.ibm.com
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Hi Luis,

On Thu, Apr 14, 2022 at 1:34 PM Luis Chamberlain <mcgrof@kernel.org> wrote:
>
> On Thu, Apr 14, 2022 at 12:59:13PM -0700, Song Liu wrote:
> > Introduce module_alloc_huge, which allocates huge page backed memory in
> > module memory space. The primary user of this memory is bpf_prog_pack
> > (multiple BPF programs sharing a huge page).
> >
> > Signed-off-by: Song Liu <song@kernel.org>
>
> See modules-next [0], as modules.c has been chopped up as of late.
> So if you want this to go throug modules this will need to rebased
> on that tree. fortunately the amount of code in question does not
> seem like much.
>
> [0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=modules-next

We are hoping to ship this with to 5.18, as the set addresses some issue with
huge page backed vmalloc. I guess we cannot ship it via modules-next branch.

How about we ship module_alloc_huge() to 5.18 in module.c for now, and once
we update modules-next branch, I will send another patch to clean it up?

Thanks,
Song