Re: [PATCH v2 5/9] mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage

[Miaohe Lin]

On 2022/6/24 7:51, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
> 
> Raw error info list needs to be removed when hwpoisoned hugetlb is
> unpoisioned.  And unpoison handler needs to know how many errors there
> are in the target hugepage. So add them.
> 
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>

snip

> @@ -2255,7 +2275,7 @@ int unpoison_memory(unsigned long pfn)
>  unlock_mutex:
>  	mutex_unlock(&mf_mutex);
>  	if (!ret || freeit) {
> -		num_poisoned_pages_dec();
> +		num_poisoned_pages_sub(count);

IIUC, num_poisoned_pages will only be incremented once for hugetlb page. If many
subpages are hwpoisoned, they will reach the "else if (res == -EHWPOISON)" path
in try_memory_failure_hugetlb and thus num_poisoned_pages_inc is ignored. Maybe
that should be changed so subpages can contribute to the num_poisoned_pages
or should we just do num_poisoned_pages_dec here? Or am I miss something?

Thanks!

>  		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
>  				 page_to_pfn(p), &unpoison_rs);
>  	}
>