From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id D90C46B0038 for ; Tue, 3 Oct 2017 03:49:13 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id u78so7136188wmd.4 for ; Tue, 03 Oct 2017 00:49:13 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id t104sor4411145wrc.35.2017.10.03.00.49.12 for (Google Transport Security); Tue, 03 Oct 2017 00:49:12 -0700 (PDT) Date: Tue, 3 Oct 2017 09:49:01 +0200 From: Alexandru Moise <00moses.alexander00@gmail.com> Subject: Re: + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree Message-ID: <20171003074901.GA10409@gmail.com> References: <59cd6cfc.gjq2hAb82xF6wYrU%akpm@linux-foundation.org> <20171003073301.hydw7jf2wztsx2om@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171003073301.hydw7jf2wztsx2om@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: akpm@linux-foundation.org, aneesh.kumar@linux.vnet.ibm.com, gerald.schaefer@de.ibm.com, khandual@linux.vnet.ibm.com, kirill@shutemov.name, mike.kravetz@oracle.com, n-horiguchi@ah.jp.nec.com, punit.agrawal@arm.com, mm-commits@vger.kernel.org, linux-mm@kvack.org On Tue, Oct 03, 2017 at 09:33:01AM +0200, Michal Hocko wrote: > I am sorry to jump here late > > On Thu 28-09-17 14:43:24, Andrew Morton wrote: > > From: Alexandru Moise <00moses.alexander00@gmail.com> > > Subject: mm/madvise: enable soft offline of HugeTLB pages at PUD level > > > > Since 94310cbcaa3c2 ("mm/madvise: enable (soft|hard) offline of HugeTLB > > pages at PGD level") we've been able to soft offline 1G hugepages at the > > PGD level, however x86_64 gigantic hugepages are at the PUD level so we > > should add an extra check to account for hstate order at PUD level. > > > > I'm not sure if this also applies to 5 level page tables on x86_64 > > however. Tested with 4 level pagetable. > > This patch is wrong I believe! And I suspect 94310cbcaa3c2 is wrong as > well but I am not familiar with ppc enough to be sure. It will allow > PUD, PGD pages to be allocated from the zone movable while at least PUD > pages are not migrateable for x86_64 AFAIR. Are PGD pages migrateable > on ppc? If yes, are there any other architectures to allow PGD hugetlb > pages which are not migrateable? > > Andrew, could you drop it please? > What exactly makes it wrong? When I tested this I saw no failure, copy_huge_page() seems to take into account gigantic hugepages, and when you move the mapping you don't really care about the page size? ../Alex > > Link: http://lkml.kernel.org/r/20170913101047.GA13026@gmail.com > > Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> > > Cc: Michal Hocko > > Cc: Aneesh Kumar K.V > > Cc: Naoya Horiguchi > > Cc: Mike Kravetz > > Cc: Anshuman Khandual > > Cc: Punit Agrawal > > Cc: Gerald Schaefer > > Cc: "Kirill A. Shutemov" > > Signed-off-by: Andrew Morton > > --- > > > > include/linux/hugetlb.h | 1 + > > 1 file changed, 1 insertion(+) > > > > diff -puN include/linux/hugetlb.h~mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level include/linux/hugetlb.h > > --- a/include/linux/hugetlb.h~mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level > > +++ a/include/linux/hugetlb.h > > @@ -480,6 +480,7 @@ static inline bool hugepage_migration_su > > { > > #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION > > if ((huge_page_shift(h) == PMD_SHIFT) || > > + (huge_page_shift(h) == PUD_SHIFT) || > > (huge_page_shift(h) == PGDIR_SHIFT)) > > return true; > > else > > _ > > > > Patches currently in -mm which might be from 00moses.alexander00@gmail.com are > > > > mm-hugetlb-soft_offline-save-compound-page-order-before-page-migration.patch > > mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch > > > > -- > Michal Hocko > SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org