| Message ID | 1560154686-18497-2-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, 10 Jun 2019 17:18:05 +0900 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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. Please describe the user-visible runtime effects of this change?
On Mon, Jun 10, 2019 at 02:20:33PM -0700, Andrew Morton wrote: > On Mon, 10 Jun 2019 17:18:05 +0900 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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. > > Please describe the user-visible runtime effects of this change? Sorry, could you replace the description as follows (I inserted one sentence)? 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. It might lead us to misjudge the test result when set_hwpoison_free_buddy_page() fails. So this patch is suggesting to fix it. Thanks, Naoya Horiguchi
On 6/10/19 1:18 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. > > 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: Mike Kravetz <mike.kravetz@oracle.com> To follow-up on Andrew's comment/question about user visible effects. Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the original page and will not return an error. Are there any other visible effects?
On Mon, Jun 10, 2019 at 05:19:45PM -0700, Mike Kravetz wrote: > On 6/10/19 1:18 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. > > > > 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: Mike Kravetz <mike.kravetz@oracle.com> Thank you, Mike. > > To follow-up on Andrew's comment/question about user visible effects. Without > this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the > original page and will not return an error. Yes, that's right. > Are there any other visible > effects? I can't think of other ones. - Naoya
On 06/11/2019 06:27 AM, Naoya Horiguchi wrote: > On Mon, Jun 10, 2019 at 05:19:45PM -0700, Mike Kravetz wrote: >> On 6/10/19 1:18 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. >>> >>> 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: Mike Kravetz <mike.kravetz@oracle.com> > > Thank you, Mike. > >> >> To follow-up on Andrew's comment/question about user visible effects. Without >> this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the >> original page and will not return an error. > > Yes, that's right. Then should this be included in the commit message as well ?
On Tue, Jun 11, 2019 at 01:44:46PM +0530, Anshuman Khandual wrote: > > > On 06/11/2019 06:27 AM, Naoya Horiguchi wrote: > > On Mon, Jun 10, 2019 at 05:19:45PM -0700, Mike Kravetz wrote: > >> On 6/10/19 1:18 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. > >>> > >>> 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: Mike Kravetz <mike.kravetz@oracle.com> > > > > Thank you, Mike. > > > >> > >> To follow-up on Andrew's comment/question about user visible effects. Without > >> this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the > >> original page and will not return an error. > > > > Yes, that's right. > > Then should this be included in the commit message as well ? Right, I'll clarify the point in the description. Thanks, - Naoya
diff --git v5.2-rc3/mm/memory-failure.c v5.2-rc3_patched/mm/memory-failure.c index fc8b517..7ea485e 100644 --- v5.2-rc3/mm/memory-failure.c +++ v5.2-rc3_patched/mm/memory-failure.c @@ -1733,6 +1733,8 @@ 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. 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+ --- mm/memory-failure.c | 2 ++ 1 file changed, 2 insertions(+)