Re: [PATCH 2/2] mm: memory-failure: kill __soft_offline_page()

[Kefeng Wang]

On 2022/8/30 15:15, HORIGUCHI NAOYA(堀口 直也) wrote:
> On Fri, Aug 19, 2022 at 11:34:02AM +0800, Kefeng Wang wrote:
> > Squash the __soft_offline_page() into soft_offline_in_use_page() and
> > kill __soft_offline_page().
> >
> > Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> > ---
> >   mm/memory-failure.c | 24 +++++++++---------------
> >   1 file changed, 9 insertions(+), 15 deletions(-)
> >
> > diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> > index 1a7d6548ccb2..5b368124956d 100644
> > --- a/mm/memory-failure.c
> > +++ b/mm/memory-failure.c
> > @@ -2432,11 +2432,11 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
> >   }
> >   
> >   /*
> > - * __soft_offline_page handles hugetlb-pages and non-hugetlb pages.
> > + * soft_offline_in_use_page handles hugetlb-pages and non-hugetlb pages.
> >    * If the page is a non-dirty unmapped page-cache page, it simply invalidates.
> >    * If the page is mapped, it migrates the contents over.
> >    */
> > -static int __soft_offline_page(struct page *page)
> > +static int soft_offline_in_use_page(struct page *page)
> >   {
> >   	long ret = 0;
> >   	unsigned long pfn = page_to_pfn(page);
> > @@ -2449,6 +2449,13 @@ static int __soft_offline_page(struct page *page)
> >   		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
> >   	};
> >   
> > +	if (!huge && PageTransHuge(hpage)) {
> > +		if (try_to_split_thp_page(page)) {
> > +			pr_info("soft offline: %#lx: thp split failed\n", pfn);
> > +			return -EBUSY;
> > +		}
> I've found that this change causes a regression. After the thp is
> successfully split here, hpage no longer points to a proper page.
> So hpage should be updated to point to the raw error page.
>
> +		hpage = page;
Sorry for the regression,  will update.
> Could you update the patch?
>
> Thanks,
> Naoya Horiguchi