On Tue, 12 Jan 2016 12:10:45 +0900 Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> wrote:
> Currently memory_failure() doesn't handle non anonymous thp case, because we
> can hardly expect the error handling to be successful, and it can just hit
> some corner case which results in BUG_ON or something severe like that.
> This is also the case for soft offline code, so let's make it in the same way.
>
> Orignal code has a MF_COUNT_INCREASED check before put_hwpoison_page(), but
> it's unnecessary because get_any_page() is already called when running on
> this code, which takes a refcount of the target page regardress of the flag.
> So this patch also removes it.
>
> ...
>
> --- next-20160111/mm/memory-failure.c
> +++ next-20160111_patched/mm/memory-failure.c
> @@ -1691,16 +1691,16 @@ static int soft_offline_in_use_page(struct page *page, int flags)
>
> if (!PageHuge(page) && PageTransHuge(hpage)) {
> lock_page(hpage);
> - ret = split_huge_page(hpage);
> - unlock_page(hpage);
> - if (unlikely(ret || PageTransCompound(page) ||
> - !PageAnon(page))) {
> - pr_info("soft offline: %#lx: failed to split THP\n",
> - page_to_pfn(page));
> - if (flags & MF_COUNT_INCREASED)
> - put_hwpoison_page(hpage);
> + if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
> + unlock_page(hpage);
> + if (!PageAnon(hpage))
> + pr_info("soft offline: %#lx: non anonymous thp\n", pfn);
> + else
> + pr_info("soft offline: %#lx: thp split failed\n", pfn);
> + put_hwpoison_page(hpage);
> return -EBUSY;
> }
hm, what happened there.
mm/memory-failure.c: In function 'soft_offline_in_use_page':
mm/memory-failure.c:1697: error: 'pfn' undeclared (first use in this function)
mm/memory-failure.c:1697: error: (Each undeclared identifier is reported only once
mm/memory-failure.c:1697: error: for each function it appears in.)
--- a/mm/memory-failure.c~mm-soft-offline-exit-with-failure-for-non-anonymous-thp-fix
+++ a/mm/memory-failure.c
@@ -1694,9 +1694,9 @@ static int soft_offline_in_use_page(stru
if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
unlock_page(hpage);
if (!PageAnon(hpage))
- pr_info("soft offline: %#lx: non anonymous thp\n", pfn);
+ pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
else
- pr_info("soft offline: %#lx: thp split failed\n", pfn);
+ pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
put_hwpoison_page(hpage);
return -EBUSY;
}
_
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