linux-kernel - Re: Re: [PATCH] mm/hwpoison: dissolve error hugepages of file mapping

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Date:   Fri, 16 Jul 2021 09:00:28 +0800
From:   Bin Wang <wangbin224@...wei.com>
To:     <willy@...radead.org>
CC:     <akpm@...ux-foundation.org>, <linux-kernel@...r.kernel.org>,
        <linux-mm@...ck.org>, <naoya.horiguchi@....com>,
        <wangbin224@...wei.com>, <wuxu.wu@...wei.com>
Subject: Re: Re: [PATCH] mm/hwpoison: dissolve error hugepages of file mapping

Hi Matthew,

On Thu, 15 Jul 2021 at 16:22:40 +0100, Matthew Wilcox wrote:
> How is that safe?  If you're going to dissolve the huge page, you
> need to figure out which subpage needs to have the HWPoison flag set.

Thanks for your review. The p that we pass to the __page_handle_poison()
is the error subpage. And we will move the HWPoison flag to subpage in
the dissolve_free_huge_page():

if (PageHWPoison(head) && page != head) {
	SetPageHWPoison(page);
	ClearPageHWPoison(head);
}

Thanks,
Bin Wang