From: SeongJae Park <sj@kernel.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
damon@lists.linux.dev, linux-mm@kvack.org,
vishal.moola@gmail.com, david@redhat.com
Subject: Re: [PATCH -next v2 2/7] mm: damon: introduce damon_get_folio()
Date: Tue, 27 Dec 2022 21:38:33 +0000 [thread overview]
Message-ID: <20221227213833.3261-1-sj@kernel.org> (raw)
In-Reply-To: <Y6tMZNvTF4ZsoQEq@casper.infradead.org>
On Tue, 27 Dec 2022 19:49:56 +0000 Matthew Wilcox <willy@infradead.org> wrote:
> On Tue, Dec 27, 2022 at 07:42:57PM +0000, SeongJae Park wrote:
> > > +static inline struct page *damon_get_page(unsigned long pfn)
> > > +{
> > > + struct folio *folio = damon_get_folio(pfn);
> > > +
> > > + return &folio->page;
> >
> > I think we should check if folio is NULL before dereferencing it?
>
> &folio->page does not dereeference folio.
Ah, ok. And this is safe because ->page is at the beginning of folio, right?
Kefeng, could we add a comment explaining it, for people having bad eyes like
me?
Thanks,
SJ
next prev parent reply other threads:[~2022-12-27 21:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-27 12:27 [PATCH -next v2 0/7] mm: convert page_idle/damon to use folios Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 1/7] mm: page_idle: Convert page idle " Kefeng Wang
2022-12-27 18:14 ` Matthew Wilcox
2022-12-28 1:18 ` Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 2/7] mm: damon: introduce damon_get_folio() Kefeng Wang
2022-12-27 19:42 ` SeongJae Park
2022-12-27 19:49 ` Matthew Wilcox
2022-12-27 21:38 ` SeongJae Park [this message]
2022-12-28 2:06 ` Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 3/7] mm: damon: convert damon_ptep/pmdp_mkold() to use folios Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 4/7] mm: damon: paddr: convert damon_pa_*() " Kefeng Wang
2022-12-27 19:50 ` SeongJae Park
2022-12-28 1:26 ` Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 5/7] mm: damon: vaddr: convert damon_young_pmd_entry() to use folio Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 6/7] mm: damon: remove unneed damon_get_page() Kefeng Wang
2022-12-27 12:27 ` [PATCH -next v2 7/7] mm: damon: vaddr: convert hugetlb related function to use folios Kefeng Wang
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