Re: [PATCH v9 0/4] mm: Enable conversion of powerpc to default topdown mmap layout

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 09/04/2022 à 05:25, Andrew Morton a écrit :
> On Fri,  8 Apr 2022 09:24:58 +0200 Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
> 
>> Rebased on top of Linux 5.18-rc1
>>
>> This is the mm part of the series that converts powerpc to default
>> topdown mmap layout, for merge into v5.18
> 
> We're at 5.18-rc1.  The 5.18 merge window has closed and we're in
> fixes-only mode.

Umm ... There must have been a misunderstanding then.

I contacted you before the merge window, and your answer was:

Le 11/03/2022 à 05:49, Andrew Morton a écrit :
>
> 5.18 isn't a problem.  Perhaps you meant 5.17, which would be real tough.
>
> Can we take a look after 5.18-rc1?


> 
> If there's a case to be made that these patches are needed by 5.18
> users then please let's make that case.  Otherwise, this is 5.19-rc1 material.

It's not really needed for 5.18. The idea was to merge that common part 
in 5.18 in order to minimise risks on conflicts. As far as I understand 
it often happens that changes of that kind get merged at the very end of 
the merge window or between rc1 and rc2. I was therefore not surprised 
that you offered to handle it past rc1.

History at:
https://patchwork.ozlabs.org/project/linuxppc-dev/cover/cover.1646847561.git.christophe.leroy@csgroup.eu/#2856080


> 
> And if it is indeed all 5.19-rc1 material, then please carry all four
> in the powerpc tree with Acked-by: Andrew Morton
> <akpm@linux-foundation.org>.

Well, Michael was a bit unconfortable with doing it that way, see below:


Le 11/03/2022 à 05:26, Michael Ellerman a écrit :
 >
 > Yeah I didn't pick it up because the mm changes don't have many acks and
 > I'm always nervous about carrying generic mm changes.
 >
 > It would be my preference if Andrew could take 2-5 through mm for v5.18,
 > but it is quite late, so I'm not sure how he will feel about that.
 >
 > Arguably 2, 3, 4 do very little. It's only patch 5 that has much effect,
 > and it has a reviewed-by from Catalin at least.

Michael, is it now ok for you to merge it via powerpc tree with Andrew's 
Ack ?

> 
> Also, [4/4] has a cc:stable.  This is a bit odd because -stable
> candidates should be standalone patches, staged ahead of all
> for-next-merge-window material, so we can get them merged up quickly.
> 
> More oddly, [4/4]'s changelog provides no explanation for why the patch
> should be considered for backporting.
> 

That was a request from Catalin from ARM64:

Le 04/01/2022 à 17:21, Catalin Marinas a écrit :
 > I wonder whether we should add a fixes tag (or at least the cc stable):
 >
 > Fixes: f6795053dac8 ("mm: mmap: Allow for "high" userspace addresses")
 > Cc: <stable@vger.kernel.org> # 5.0.x
 >
 > I think the original commit should have changed
 > hugetlb_get_unmapped_area() to have the same behaviour as
 > arch_get_unmapped_area(). Steve, any thoughts?
 >
 > FWIW,
 >
 > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

 From 
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/db238c1ca2d46e33c57328f8d450f2563e92f8c2.1639736449.git.christophe.leroy@csgroup.eu/

I can try and see whether this can be moved in front of the other patches.

Thanks
Christophe