| Message ID | 1560761476-4651-2-git-send-email-n-horiguchi@ah.jp.nec.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix return value issue of soft offlining hugepages | expand |
On Mon, Jun 17, 2019 at 05:51:15PM +0900, Naoya Horiguchi wrote: > The pass/fail of soft offline should be judged by checking whether the > raw error page was finally contained or not (i.e. the result of > set_hwpoison_free_buddy_page()), but current code do not work like that. > So this patch is suggesting to fix it. > > Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may > not offline the original page and will not return an error. It might > lead us to misjudge the test result when set_hwpoison_free_buddy_page() > actually fails. > > Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining") > Cc: <stable@vger.kernel.org> # v4.19+ Reviewed-by: Oscar Salvador <osalvador@suse.de> > --- > ChangeLog v2->v3: > - update patch description to clarify user visible change > --- > mm/memory-failure.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git v5.2-rc4/mm/memory-failure.c v5.2-rc4_patched/mm/memory-failure.c > index 8da0334..8ee7b16 100644 > --- v5.2-rc4/mm/memory-failure.c > +++ v5.2-rc4_patched/mm/memory-failure.c > @@ -1730,6 +1730,8 @@ static int soft_offline_huge_page(struct page *page, int flags) > if (!ret) { > if (set_hwpoison_free_buddy_page(page)) > num_poisoned_pages_inc(); > + else > + ret = -EBUSY; > } > } > return ret; > -- > 2.7.0 >
On 6/17/19 1:51 AM, Naoya Horiguchi wrote: > The pass/fail of soft offline should be judged by checking whether the > raw error page was finally contained or not (i.e. the result of > set_hwpoison_free_buddy_page()), but current code do not work like that. > So this patch is suggesting to fix it. > > Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may > not offline the original page and will not return an error. It might > lead us to misjudge the test result when set_hwpoison_free_buddy_page() > actually fails. > > Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Thanks for the updates, Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
diff --git v5.2-rc4/mm/memory-failure.c v5.2-rc4_patched/mm/memory-failure.c index 8da0334..8ee7b16 100644 --- v5.2-rc4/mm/memory-failure.c +++ v5.2-rc4_patched/mm/memory-failure.c @@ -1730,6 +1730,8 @@ static int soft_offline_huge_page(struct page *page, int flags) if (!ret) { if (set_hwpoison_free_buddy_page(page)) num_poisoned_pages_inc(); + else + ret = -EBUSY; } } return ret;
The pass/fail of soft offline should be judged by checking whether the raw error page was finally contained or not (i.e. the result of set_hwpoison_free_buddy_page()), but current code do not work like that. So this patch is suggesting to fix it. Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the original page and will not return an error. It might lead us to misjudge the test result when set_hwpoison_free_buddy_page() actually fails. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining") Cc: <stable@vger.kernel.org> # v4.19+ --- ChangeLog v2->v3: - update patch description to clarify user visible change --- mm/memory-failure.c | 2 ++ 1 file changed, 2 insertions(+)