Re: Linux 5.18-rc4

From: Andrew Morton
Date: Mon Apr 25 2022 - 18:24:44 EST


On Mon, 25 Apr 2022 10:50:57 +0100 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> wrote:

> Hi Linus,
>
> On Sun, Apr 24, 2022 at 03:22:59PM -0700, Linus Torvalds wrote:
> > Fairly slow and calm week - which makes me just suspect that the other
> > shoe will drop at some point.
> >
> > But maybe things are just going really well this release. It's bound
> > to happen _occasionally_, after all.
>
> My last night's mainline build failed for arm.
> Build was with af2d861d4cd2 ("Linux 5.18-rc4").
>
> imxrt_defconfig -> failed
> lpc18xx_defconfig -> failed
> mps2_defconfig -> failed
> stm32_defconfig -> failed
> vf610m4_defconfig -> failed
>
> arm-linux-gnueabi-ld: mm/page_alloc.o: in function `alloc_large_system_hash':
> page_alloc.c:(.init.text+0xe7c): undefined reference to `vmalloc_huge'

Thanks. oops. We broke nommu.

From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm/nommu.c: provide vmalloc_huge() for CONFIG_MMU=n

Fixes: f2edd118d02dd ("page_alloc: use vmalloc_huge for large system hash")
Reported-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

mm/nommu.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/mm/nommu.c~a
+++ a/mm/nommu.c
@@ -226,6 +226,12 @@ void *vmalloc(unsigned long size)
}
EXPORT_SYMBOL(vmalloc);

+void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
+{
+ return vmalloc(size);
+}
+EXPORT_SYMBOL(vmalloc_huge);
+
/*
* vzalloc - allocate virtually contiguous memory with zero fill
*
_


I don't see any point in copy-n-pasting the kerneldoc over. Perhaps we
should just delete all the copy-n-paste kerneldoc from nommu.c and say
"go look at the MMU version of this function".