linux-kernel - Re: [PATCH v2 1/1] mm: prevent poison consumption when splitting THP

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Message-ID: <20251012012338.p5z2oyyymjxa4wni@master>
Date: Sun, 12 Oct 2025 01:23:38 +0000
From: Wei Yang <richard.weiyang@...il.com>
To: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
Cc: akpm@...ux-foundation.org, david@...hat.com, lorenzo.stoakes@...cle.com,
	linmiaohe@...wei.com, tony.luck@...el.com, ziy@...dia.com,
	baolin.wang@...ux.alibaba.com, Liam.Howlett@...cle.com,
	npache@...hat.com, ryan.roberts@....com, dev.jain@....com,
	baohua@...nel.org, nao.horiguchi@...il.com, farrah.chen@...el.com,
	jiaqiyan@...gle.com, lance.yang@...ux.dev, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/1] mm: prevent poison consumption when splitting THP

On Sat, Oct 11, 2025 at 03:55:19PM +0800, Qiuxu Zhuo wrote:
[...]
>
>diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>index 9c38a95e9f09..2bf5178cca96 100644
>--- a/mm/huge_memory.c
>+++ b/mm/huge_memory.c
>@@ -4121,6 +4121,9 @@ static bool thp_underused(struct folio *folio)
> 	if (khugepaged_max_ptes_none == HPAGE_PMD_NR - 1)
> 		return false;
> 
>+	if (folio_contain_hwpoisoned_page(folio))
>+		return false;
>+
> 	for (i = 0; i < folio_nr_pages(folio); i++) {
> 		kaddr = kmap_local_folio(folio, i * PAGE_SIZE);
> 		if (!memchr_inv(kaddr, 0, PAGE_SIZE)) {
>diff --git a/mm/migrate.c b/mm/migrate.c
>index 9e5ef39ce73a..393fc2ffc96e 100644
>--- a/mm/migrate.c
>+++ b/mm/migrate.c
>@@ -305,8 +305,9 @@ static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw,
> 	pte_t newpte;
> 	void *addr;
> 
>-	if (PageCompound(page))
>+	if (PageCompound(page) || PageHWPoison(page))
> 		return false;
>+
> 	VM_BUG_ON_PAGE(!PageAnon(page), page);
> 	VM_BUG_ON_PAGE(!PageLocked(page), page);
> 	VM_BUG_ON_PAGE(pte_present(ptep_get(pvmw->pte)), page);
>

The code change LGTM.

Reviewed-by: Wei Yang <richard.weiyang@...il.com>

>base-commit: e5f0a698b34ed76002dc5cff3804a61c80233a7a
>-- 
>2.43.0
>

-- 
Wei Yang
Help you, Help me