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Date:   Thu, 18 Mar 2021 11:15:46 +0800
From:   Aili Yao <yaoaili@kingsoft.com>
To:     David Hildenbrand <david@redhat.com>
CC:     <akpm@linux-foundation.org>, <naoya.horiguchi@nec.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <yangfeng1@kingsoft.com>, <sunhao2@kingsoft.com>,
        Oscar Salvador <osalvador@suse.de>,
        Mike Kravetz <mike.kravetz@oracle.com>, <yaoaili@kingsoft.com>
Subject: Re: [PATCH] mm/gup: check page posion status for coredump.
Message-ID: <20210318111546.4bda8c7a@alex-virtual-machine>
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References: <20210317163714.328a038d@alex-virtual-machine>
        <20a0d078-f49d-54d6-9f04-f6b41dd51e5f@redhat.com>
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On Wed, 17 Mar 2021 10:12:02 +0100
David Hildenbrand <david@redhat.com> wrote:

> 
> I wonder if a simple
> 
> if (PageHWPoison(compound_head(page)))
> 	ret = 0;
> 
> won't suffice. But I guess the "issue" is compound pages that are not 
> huge pages or transparent huge pages.

Yes, the simple case won't suffice, as we mark the hugetlb page poison in head, and
other cases in the specific single page struct.

> If not, we certainly want a wrapper for that magic, otherwise we have to 
> replicate the same logic all over the place.
> 
> > +
> >   	return (ret == 1) ? page : NULL;
> >   }
> >   #endif /* CONFIG_ELF_CORE */
> >   
> 
> 

Yes, May other places meet the requirements as the coredump meets, it's better to make a
wrapper for this. But i am not familiar with the specific scenario, so this patch only cover
the coredump case.

I will post a v2 patch for this.

-- 
Thanks!
Aili Yao