* + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree
@ 2017-09-28 21:43 akpm
2017-10-03 7:33 ` Michal Hocko
0 siblings, 1 reply; 5+ messages in thread
From: akpm @ 2017-09-28 21:43 UTC (permalink / raw)
To: 00moses.alexander00, aneesh.kumar, gerald.schaefer, khandual,
kirill, mhocko, mike.kravetz, n-horiguchi, punit.agrawal,
mm-commits
The patch titled
Subject: mm/madvise: enable soft offline of HugeTLB pages at PUD level
has been added to the -mm tree. Its filename is
mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
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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.
Link: http://lkml.kernel.org/r/20170913101047.GA13026@gmail.com
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
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
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree
2017-09-28 21:43 + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree akpm
@ 2017-10-03 7:33 ` Michal Hocko
2017-10-03 7:49 ` Alexandru Moise
0 siblings, 1 reply; 5+ messages in thread
From: Michal Hocko @ 2017-10-03 7:33 UTC (permalink / raw)
To: akpm
Cc: 00moses.alexander00, aneesh.kumar, gerald.schaefer, khandual,
kirill, mike.kravetz, n-horiguchi, punit.agrawal, mm-commits,
linux-mm
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?
> Link: http://lkml.kernel.org/r/20170913101047.GA13026@gmail.com
> Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Cc: Mike Kravetz <mike.kravetz@oracle.com>
> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> Cc: Punit Agrawal <punit.agrawal@arm.com>
> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
> Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
> 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
--
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree
2017-10-03 7:33 ` Michal Hocko
@ 2017-10-03 7:49 ` Alexandru Moise
2017-10-03 8:00 ` Michal Hocko
0 siblings, 1 reply; 5+ messages in thread
From: Alexandru Moise @ 2017-10-03 7:49 UTC (permalink / raw)
To: Michal Hocko
Cc: akpm, aneesh.kumar, gerald.schaefer, khandual, kirill,
mike.kravetz, n-horiguchi, punit.agrawal, mm-commits, linux-mm
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 <mhocko@suse.com>
> > Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> > Cc: Mike Kravetz <mike.kravetz@oracle.com>
> > Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> > Cc: Punit Agrawal <punit.agrawal@arm.com>
> > Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
> > Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> > ---
> >
> > 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
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree
2017-10-03 7:49 ` Alexandru Moise
@ 2017-10-03 8:00 ` Michal Hocko
2017-10-03 8:15 ` Alexandru Moise
0 siblings, 1 reply; 5+ messages in thread
From: Michal Hocko @ 2017-10-03 8:00 UTC (permalink / raw)
To: Alexandru Moise
Cc: akpm, aneesh.kumar, gerald.schaefer, khandual, kirill,
mike.kravetz, n-horiguchi, punit.agrawal, mm-commits, linux-mm
On Tue 03-10-17 09:49:01, Alexandru Moise wrote:
> 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?
Migrating 1GB (PUD) pages on x86_64 is just too easy to fail (if it
works at all) and so such an allocation can easily prefent memory
offline to succeed. Have you tested that scenario?
Btw. (ab)using hugepage_migration_supported for HWpoinsoning sounds
wrong to me. You do not need movable zone for the functionality.
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree
2017-10-03 8:00 ` Michal Hocko
@ 2017-10-03 8:15 ` Alexandru Moise
0 siblings, 0 replies; 5+ messages in thread
From: Alexandru Moise @ 2017-10-03 8:15 UTC (permalink / raw)
To: Michal Hocko
Cc: akpm, aneesh.kumar, gerald.schaefer, khandual, kirill,
mike.kravetz, n-horiguchi, punit.agrawal, mm-commits, linux-mm
On Tue, Oct 03, 2017 at 10:00:14AM +0200, Michal Hocko wrote:
> On Tue 03-10-17 09:49:01, Alexandru Moise wrote:
> > 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?
>
> Migrating 1GB (PUD) pages on x86_64 is just too easy to fail (if it
> works at all) and so such an allocation can easily prefent memory
> offline to succeed. Have you tested that scenario?
Soft offline works if you have an availlable page in the free list or
overcommit pages. If you fail to allocate one then soft offline fails
and the page stays mapped where it is.
There was also a refcount fix for the event in which soft offline fails
for hugepages. (commit 30809f559a) I started looking around this area
when I had to backport that fix to an older kernel.
../Alex
>
> Btw. (ab)using hugepage_migration_supported for HWpoinsoning sounds
> wrong to me. You do not need movable zone for the functionality.
> --
> Michal Hocko
> SUSE Labs
--
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-10-03 8:15 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-09-28 21:43 + mm-madvise-enable-soft-offline-of-hugetlb-pages-at-pud-level.patch added to -mm tree akpm
2017-10-03 7:33 ` Michal Hocko
2017-10-03 7:49 ` Alexandru Moise
2017-10-03 8:00 ` Michal Hocko
2017-10-03 8:15 ` Alexandru Moise
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