On 08/21/2018 06:37 PM, Naoya Horiguchi wrote: > On Wed, Aug 15, 2018 at 03:43:34PM -0700, Andrew Morton wrote: >> On Tue, 17 Jul 2018 14:32:30 +0900 Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> wrote: >> >>> I've updated the patchset based on feedbacks: >>> >>> - updated comments (from Andrew), >>> - moved calling set_hwpoison_free_buddy_page() from mm/migrate.c to mm/memory-failure.c, >>> which is necessary to check the return code of set_hwpoison_free_buddy_page(), >>> - lkp bot reported a build error when only 1/2 is applied. >>> >>> > mm/memory-failure.c: In function 'soft_offline_huge_page': >>> > >> mm/memory-failure.c:1610:8: error: implicit declaration of function >>> > 'set_hwpoison_free_buddy_page'; did you mean 'is_free_buddy_page'? >>> > [-Werror=implicit-function-declaration] >>> > if (set_hwpoison_free_buddy_page(page)) >>> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> > is_free_buddy_page >>> > cc1: some warnings being treated as errors >>> >>> set_hwpoison_free_buddy_page() is defined in 2/2, so we can't use it >>> in 1/2. Simply doing s/set_hwpoison_free_buddy_page/!TestSetPageHWPoison/ >>> will fix this. >>> >>> v1: https://lkml.org/lkml/2018/7/12/968 >>> >> >> Quite a bit of discussion on these two, but no actual acks or >> review-by's? > > Really sorry for late response. > Xishi provided feedback on previous version, but no final ack/reviewed-by. > This fix should work on the reported issue, but rewriting soft-offlining > without PageHWPoison flag would be the better fix (no actual patch yet.) > I'm not sure this patch should go to mainline immediately. FWIW - The 'migration of huge PMD shared pages' issue I am working was originally triggered via soft-offline. While working the issue, I tried to exercise huge page soft-offline really hard to recreate the issue and validate a fix. However, I was more likely to hit the soft-offline race(s) your patches address. Therefore, I applied your patches to focus my testing and validation on the migration of huge PMD shared pages issue. That is sort of a Tested-by :). Just wanted to point out that it was pretty easy to hit this issue. It was easier than the issue I am working. And, the issue I am trying to address was seen in a real customer environment. So, I would not be surprised to see this issue in real customer environments as well. If you (or others) think we should go forward with these patches, I can spend some time doing a review. Already did a 'quick look' some time back. -- Mike Kravetz
