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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 25 Apr 2022 09:07:12 +0200
Message-ID: <CAMuHMdVdx2V1uhv_152Sw3_z2xE0spiaWp1d6Ko8-rYmAxUBAg@mail.gmail.com>
Subject: Re: [PATCH v4 bpf 2/4] page_alloc: use vmalloc_huge for large system hash
To:     "song@kernel.org" <song@kernel.org>
Cc:     "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Rik van Riel <riel@fb.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
        "rick.p.edgecombe@intel.com" <rick.p.edgecombe@intel.com>,
        "hch@lst.de" <hch@lst.de>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "daniel@iogearbox.net" <daniel@iogearbox.net>,
        "hch@infradead.org" <hch@infradead.org>,
        "mcgrof@kernel.org" <mcgrof@kernel.org>,
        "ast@kernel.org" <ast@kernel.org>,
        Kernel Team <Kernel-team@fb.com>,
        "imbrenda@linux.ibm.com" <imbrenda@linux.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
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Hi Song,

On Fri, 2022-04-15 at 09:44 -0700, Song Liu wrote:
> > Use vmalloc_huge() in alloc_large_system_hash() so that large system
> > hash
> > (>= PMD_SIZE) could benefit from huge pages. Note that vmalloc_huge
> > only
> > allocates huge pages for systems with HAVE_ARCH_HUGE_VMALLOC.
> >
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Signed-off-by: Song Liu <song@kernel.org>
>
> Reviewed-by: Rik van Riel <riel@surriel.com>

Thanks for your patch, which is now commit f2edd118d02dd114
("page_alloc: use vmalloc_huge for large system hash") upstream
(and which hasn't been in linux-next before).

As reported by noreply@ellerman.id.au, this is breaking e.g.
m68k/m5272c3_defconfig with:

page_alloc.c:(.init.text+0x13de): undefined reference to `vmalloc_huge'

vmalloc_huge() is provided by mm/vmalloc.c, which is not
compiled if CONFIG_MMU=n.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds