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Date: Thu, 15 Aug 2024 22:07:09 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Uladzislau Rezki <urezki@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>, Barry Song <21cnbao@gmail.com>, Hailong
 Liu <hailong.liu@oppo.com>, Christoph Hellwig <hch@infradead.org>,
 Vlastimil Babka <vbabka@suse.cz>, Tangquan Zheng <zhengtangquan@oppo.com>,
 stable@vger.kernel.org, Baoquan He <bhe@redhat.com>, Matthew Wilcox
 <willy@infradead.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH v1] mm/vmalloc: fix page mapping if
 vm_area_alloc_pages() with high order fallback to order 0
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On Fri, 9 Aug 2024 11:41:42 +0200 Uladzislau Rezki <urezki@gmail.com> wrote:

> > > Acked-by: Barry Song <baohua@kernel.org>
> > > 
> > > because we already have a fallback here:
> > > 
> > > void *__vmalloc_node_range_noprof :
> > > 
> > > fail:
> > >         if (shift > PAGE_SHIFT) {
> > >                 shift = PAGE_SHIFT;
> > >                 align = real_align;
> > >                 size = real_size;
> > >                 goto again;
> > >         }
> > 
> > This really deserves a comment because this is not really clear at all.
> > The code is also fragile and it would benefit from some re-org.
> > 
> > Thanks for the fix.
> > 
> > Acked-by: Michal Hocko <mhocko@suse.com>
> > 
> I agree. This is only clear for people who know the code. A "fallback"
> to order-0 should be commented.

It's been a week.  Could someone please propose a fixup patch to add
this comment?