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Date:   Thu, 30 Mar 2023 19:02:39 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc:     Peng Zhang <zhangpeng362@huawei.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        mike.kravetz@oracle.com, vishal.moola@gmail.com,
        muchun.song@linux.dev, wangkefeng.wang@huawei.com,
        sunnanyong@huawei.com
Subject: Re: [PATCH v4 1/6] userfaultfd: convert mfill_atomic_pte_copy() to
 use a folio
Message-ID: <ZCXOv9rz8GCrpbMk@casper.infradead.org>
References: <20230330134045.375163-1-zhangpeng362@huawei.com>
 <20230330134045.375163-2-zhangpeng362@huawei.com>
 <765d450c-2ff6-1420-b94f-528d56bffee4@oracle.com>
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On Thu, Mar 30, 2023 at 10:02:52AM -0700, Sidhartha Kumar wrote:
> On 3/30/23 6:40 AM, Peng Zhang wrote:
> > From: ZhangPeng <zhangpeng362@huawei.com>
> > 
> > Call vma_alloc_folio() directly instead of alloc_page_vma(). Add an
> > assertion that this is a single-page folio and removes several calls to
> > compound_head().

There's no added assertion in this patch any more, so I'd drop that
part of the description.

> >   	if (!*pagep) {
> >   		ret = -ENOMEM;
> > -		page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, dst_vma, dst_addr);
> > -		if (!page)
> > +		folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
> > +		if (!folio)
> >   			goto out;
> > -		page_kaddr = kmap_local_page(page);
> > +		page_kaddr = kmap_local_folio(folio, 0);
> 
> Should this variable name be kept as page_kaddr or should it be changed to
> something like folio_kaddr? kmap_local_folio() returns page_address(), so
> maybe page_kaddr is better.

I'd just call it 'kaddr'.  Or 'addr'.