* + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch
@ 2022-07-02 4:06 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2022-07-02 4:06 UTC (permalink / raw)
To: mm-commits, songmuchun, shy828301, osalvador, mike.kravetz,
liushixin2, linmiaohe, david, naoya.horiguchi, akpm
The patch titled
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
Date: Thu, 30 Jun 2022 11:27:49 +0900
follow_pud_mask() does not support non-present pud entry now. As long as
I tested on x86_64 server, follow_pud_mask() still simply returns
no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe
user-visible effect should happen. But generally we should call
follow_huge_pud() for non-present pud entry for 1GB hugetlb page.
Update pud_huge() and follow_huge_pud() to handle non-present pud entries.
The changes are similar to previous works for pud entries commit
e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and
commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present
hugepage").
Link: https://lkml.kernel.org/r/20220630022755.3362349-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86/mm/hugetlbpage.c | 8 +++++++-
mm/hugetlb.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/arch/x86/mm/hugetlbpage.c
@@ -30,9 +30,15 @@ int pmd_huge(pmd_t pmd)
(pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
+/*
+ * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal
+ * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry.
+ * Otherwise, returns 0.
+ */
int pud_huge(pud_t pud)
{
- return !!(pud_val(pud) & _PAGE_PSE);
+ return !pud_none(pud) &&
+ (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
#ifdef CONFIG_HUGETLB_PAGE
--- a/mm/hugetlb.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/mm/hugetlb.c
@@ -6994,10 +6994,38 @@ struct page * __weak
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int flags)
{
- if (flags & (FOLL_GET | FOLL_PIN))
+ struct page *page = NULL;
+ spinlock_t *ptl;
+ pte_t pte;
+
+ if (WARN_ON_ONCE(flags & FOLL_PIN))
return NULL;
- return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+retry:
+ ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud);
+ if (!pud_huge(*pud))
+ goto out;
+ pte = huge_ptep_get((pte_t *)pud);
+ if (pte_present(pte)) {
+ page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ page = NULL;
+ goto out;
+ }
+ } else {
+ if (is_hugetlb_entry_migration(pte)) {
+ spin_unlock(ptl);
+ __migration_entry_wait(mm, (pte_t *)pud, ptl);
+ goto retry;
+ }
+ /*
+ * hwpoisoned entry is treated as no_page_table in
+ * follow_page_mask().
+ */
+ }
+out:
+ spin_unlock(ptl);
+ return page;
}
struct page * __weak
_
Patches currently in -mm which might be from naoya.horiguchi@nec.com are
mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch
mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch
mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch
mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch
mm-hwpoison-make-__page_handle_poison-returns-int.patch
mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch
mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch
@ 2022-07-04 1:40 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2022-07-04 1:40 UTC (permalink / raw)
To: mm-commits, songmuchun, shy828301, osalvador, mike.kravetz,
liushixin2, linmiaohe, david, naoya.horiguchi, akpm
The patch titled
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
Date: Mon, 4 Jul 2022 10:33:06 +0900
follow_pud_mask() does not support non-present pud entry now. As long as
I tested on x86_64 server, follow_pud_mask() still simply returns
no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe
user-visible effect should happen. But generally we should call
follow_huge_pud() for non-present pud entry for 1GB hugetlb page.
Update pud_huge() and follow_huge_pud() to handle non-present pud entries.
The changes are similar to previous works for pud entries commit
e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and
commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present
hugepage").
Link: https://lkml.kernel.org/r/20220704013312.2415700-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86/mm/hugetlbpage.c | 8 +++++++-
mm/hugetlb.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/arch/x86/mm/hugetlbpage.c
@@ -30,9 +30,15 @@ int pmd_huge(pmd_t pmd)
(pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
+/*
+ * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal
+ * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry.
+ * Otherwise, returns 0.
+ */
int pud_huge(pud_t pud)
{
- return !!(pud_val(pud) & _PAGE_PSE);
+ return !pud_none(pud) &&
+ (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
#ifdef CONFIG_HUGETLB_PAGE
--- a/mm/hugetlb.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/mm/hugetlb.c
@@ -6993,10 +6993,38 @@ struct page * __weak
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int flags)
{
- if (flags & (FOLL_GET | FOLL_PIN))
+ struct page *page = NULL;
+ spinlock_t *ptl;
+ pte_t pte;
+
+ if (WARN_ON_ONCE(flags & FOLL_PIN))
return NULL;
- return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+retry:
+ ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud);
+ if (!pud_huge(*pud))
+ goto out;
+ pte = huge_ptep_get((pte_t *)pud);
+ if (pte_present(pte)) {
+ page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ page = NULL;
+ goto out;
+ }
+ } else {
+ if (is_hugetlb_entry_migration(pte)) {
+ spin_unlock(ptl);
+ __migration_entry_wait(mm, (pte_t *)pud, ptl);
+ goto retry;
+ }
+ /*
+ * hwpoisoned entry is treated as no_page_table in
+ * follow_page_mask().
+ */
+ }
+out:
+ spin_unlock(ptl);
+ return page;
}
struct page * __weak
_
Patches currently in -mm which might be from naoya.horiguchi@nec.com are
mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch
mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch
mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch
mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch
mm-hwpoison-make-__page_handle_poison-returns-int.patch
mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch
mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch
@ 2022-07-08 20:27 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2022-07-08 20:27 UTC (permalink / raw)
To: mm-commits, songmuchun, shy828301, osalvador, mike.kravetz, lkp,
liushixin2, linmiaohe, david, naoya.horiguchi, akpm
The patch titled
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
Date: Fri, 8 Jul 2022 14:36:47 +0900
follow_pud_mask() does not support non-present pud entry now. As long as
I tested on x86_64 server, follow_pud_mask() still simply returns
no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe
user-visible effect should happen. But generally we should call
follow_huge_pud() for non-present pud entry for 1GB hugetlb page.
Update pud_huge() and follow_huge_pud() to handle non-present pud entries.
The changes are similar to previous works for pud entries commit
e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and
commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present
hugepage").
Link: https://lkml.kernel.org/r/20220708053653.964464-3-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86/mm/hugetlbpage.c | 8 +++++++-
mm/hugetlb.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/arch/x86/mm/hugetlbpage.c
@@ -30,9 +30,15 @@ int pmd_huge(pmd_t pmd)
(pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
+/*
+ * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal
+ * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry.
+ * Otherwise, returns 0.
+ */
int pud_huge(pud_t pud)
{
- return !!(pud_val(pud) & _PAGE_PSE);
+ return !pud_none(pud) &&
+ (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
#ifdef CONFIG_HUGETLB_PAGE
--- a/mm/hugetlb.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/mm/hugetlb.c
@@ -6978,10 +6978,38 @@ struct page * __weak
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int flags)
{
- if (flags & (FOLL_GET | FOLL_PIN))
+ struct page *page = NULL;
+ spinlock_t *ptl;
+ pte_t pte;
+
+ if (WARN_ON_ONCE(flags & FOLL_PIN))
return NULL;
- return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+retry:
+ ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud);
+ if (!pud_huge(*pud))
+ goto out;
+ pte = huge_ptep_get((pte_t *)pud);
+ if (pte_present(pte)) {
+ page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ page = NULL;
+ goto out;
+ }
+ } else {
+ if (is_hugetlb_entry_migration(pte)) {
+ spin_unlock(ptl);
+ __migration_entry_wait(mm, (pte_t *)pud, ptl);
+ goto retry;
+ }
+ /*
+ * hwpoisoned entry is treated as no_page_table in
+ * follow_page_mask().
+ */
+ }
+out:
+ spin_unlock(ptl);
+ return page;
}
struct page * __weak
_
Patches currently in -mm which might be from naoya.horiguchi@nec.com are
mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch
mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch
mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch
mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch
mm-hwpoison-make-__page_handle_poison-returns-int.patch
mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch
mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch
^ permalink raw reply [flat|nested] 4+ messages in thread* + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch
@ 2022-07-17 0:53 Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2022-07-17 0:53 UTC (permalink / raw)
To: mm-commits, songmuchun, shy828301, osalvador, mike.kravetz, lkp,
liushixin2, linmiaohe, david, naoya.horiguchi, akpm
The patch titled
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
Date: Thu, 14 Jul 2022 13:24:14 +0900
follow_pud_mask() does not support non-present pud entry now. As long as
I tested on x86_64 server, follow_pud_mask() still simply returns
no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe
user-visible effect should happen. But generally we should call
follow_huge_pud() for non-present pud entry for 1GB hugetlb page.
Update pud_huge() and follow_huge_pud() to handle non-present pud entries.
The changes are similar to previous works for pud entries commit
e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and
commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present
hugepage").
Link: https://lkml.kernel.org/r/20220714042420.1847125-3-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86/mm/hugetlbpage.c | 8 +++++++-
mm/hugetlb.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/arch/x86/mm/hugetlbpage.c
@@ -30,9 +30,15 @@ int pmd_huge(pmd_t pmd)
(pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
+/*
+ * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal
+ * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry.
+ * Otherwise, returns 0.
+ */
int pud_huge(pud_t pud)
{
- return !!(pud_val(pud) & _PAGE_PSE);
+ return !pud_none(pud) &&
+ (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
}
#ifdef CONFIG_HUGETLB_PAGE
--- a/mm/hugetlb.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry
+++ a/mm/hugetlb.c
@@ -6979,10 +6979,38 @@ struct page * __weak
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int flags)
{
- if (flags & (FOLL_GET | FOLL_PIN))
+ struct page *page = NULL;
+ spinlock_t *ptl;
+ pte_t pte;
+
+ if (WARN_ON_ONCE(flags & FOLL_PIN))
return NULL;
- return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+retry:
+ ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud);
+ if (!pud_huge(*pud))
+ goto out;
+ pte = huge_ptep_get((pte_t *)pud);
+ if (pte_present(pte)) {
+ page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ page = NULL;
+ goto out;
+ }
+ } else {
+ if (is_hugetlb_entry_migration(pte)) {
+ spin_unlock(ptl);
+ __migration_entry_wait(mm, (pte_t *)pud, ptl);
+ goto retry;
+ }
+ /*
+ * hwpoisoned entry is treated as no_page_table in
+ * follow_page_mask().
+ */
+ }
+out:
+ spin_unlock(ptl);
+ return page;
}
struct page * __weak
_
Patches currently in -mm which might be from naoya.horiguchi@nec.com are
mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch
mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch
mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch
mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch
mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch
mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch
mm-hwpoison-make-__page_handle_poison-returns-int.patch
mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch
mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-07-17 0:53 UTC | newest]
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2022-07-02 4:06 + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch Andrew Morton
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2022-07-04 1:40 Andrew Morton
2022-07-08 20:27 Andrew Morton
2022-07-17 0:53 Andrew Morton
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