* + mm-gup-remove-foll_migration.patch added to mm-unstable branch
@ 2022-10-18 0:46 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2022-10-18 0:46 UTC (permalink / raw)
To: mm-commits, willy, vbabka, shuah, peterx, jhubbard, jgg, hughd,
aarcange, david, akpm
The patch titled
Subject: mm/gup: remove FOLL_MIGRATION
has been added to the -mm mm-unstable branch. Its filename is
mm-gup-remove-foll_migration.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gup-remove-foll_migration.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: David Hildenbrand <david@redhat.com>
Subject: mm/gup: remove FOLL_MIGRATION
Date: Fri, 30 Sep 2022 16:19:31 +0200
Fortunately, the last user (KSM) is gone, so let's just remove this rather
special code from generic GUP handling -- especially because KSM never
required the PMD handling as KSM only deals with individual base pages.
Link: https://lkml.kernel.org/r/20220930141931.174362-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mm.h | 1
mm/gup.c | 55 +++----------------------------------------
2 files changed, 5 insertions(+), 51 deletions(-)
--- a/include/linux/mm.h~mm-gup-remove-foll_migration
+++ a/include/linux/mm.h
@@ -2920,7 +2920,6 @@ struct page *follow_page(struct vm_area_
* and return without waiting upon it */
#define FOLL_NOFAULT 0x80 /* do not fault in pages */
#define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
-#define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */
#define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */
#define FOLL_ANON 0x8000 /* don't do file mappings */
--- a/mm/gup.c~mm-gup-remove-foll_migration
+++ a/mm/gup.c
@@ -533,30 +533,13 @@ static struct page *follow_page_pte(stru
if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
(FOLL_PIN | FOLL_GET)))
return ERR_PTR(-EINVAL);
-retry:
if (unlikely(pmd_bad(*pmd)))
return no_page_table(vma, flags);
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
pte = *ptep;
- if (!pte_present(pte)) {
- swp_entry_t entry;
- /*
- * KSM's break_ksm() relies upon recognizing a ksm page
- * even while it is being migrated, so for that case we
- * need migration_entry_wait().
- */
- if (likely(!(flags & FOLL_MIGRATION)))
- goto no_page;
- if (pte_none(pte))
- goto no_page;
- entry = pte_to_swp_entry(pte);
- if (!is_migration_entry(entry))
- goto no_page;
- pte_unmap_unlock(ptep, ptl);
- migration_entry_wait(mm, pmd, address);
- goto retry;
- }
+ if (!pte_present(pte))
+ goto no_page;
if (pte_protnone(pte) && !gup_can_follow_protnone(flags))
goto no_page;
@@ -660,46 +643,18 @@ static struct page *follow_pmd_mask(stru
pmdval = READ_ONCE(*pmd);
if (pmd_none(pmdval))
return no_page_table(vma, flags);
-retry:
- if (!pmd_present(pmdval)) {
- /*
- * Should never reach here, if thp migration is not supported;
- * Otherwise, it must be a thp migration entry.
- */
- VM_BUG_ON(!thp_migration_supported() ||
- !is_pmd_migration_entry(pmdval));
-
- if (likely(!(flags & FOLL_MIGRATION)))
- return no_page_table(vma, flags);
-
- pmd_migration_entry_wait(mm, pmd);
- pmdval = READ_ONCE(*pmd);
- /*
- * MADV_DONTNEED may convert the pmd to null because
- * mmap_lock is held in read mode
- */
- if (pmd_none(pmdval))
- return no_page_table(vma, flags);
- goto retry;
- }
+ if (!pmd_present(pmdval))
+ return no_page_table(vma, flags);
if (likely(!(pmd_trans_huge(pmdval) || pmd_devmap(pmdval))))
return follow_page_pte(vma, address, pmd, flags);
if (pmd_protnone(pmdval) && !gup_can_follow_protnone(flags))
return no_page_table(vma, flags);
-retry_locked:
ptl = pmd_lock(mm, pmd);
- if (unlikely(pmd_none(*pmd))) {
- spin_unlock(ptl);
- return no_page_table(vma, flags);
- }
if (unlikely(!pmd_present(*pmd))) {
spin_unlock(ptl);
- if (likely(!(flags & FOLL_MIGRATION)))
- return no_page_table(vma, flags);
- pmd_migration_entry_wait(mm, pmd);
- goto retry_locked;
+ return no_page_table(vma, flags);
}
if (unlikely(!(pmd_trans_huge(*pmd) || pmd_devmap(pmdval)))) {
spin_unlock(ptl);
_
Patches currently in -mm which might be from david@redhat.com are
selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + mm-gup-remove-foll_migration.patch added to mm-unstable branch
@ 2022-10-21 20:01 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2022-10-21 20:01 UTC (permalink / raw)
To: mm-commits, willy, vbabka, shuah, peterx, jhubbard, jgg, hughd,
aarcange, david, akpm
The patch titled
Subject: mm/gup: remove FOLL_MIGRATION
has been added to the -mm mm-unstable branch. Its filename is
mm-gup-remove-foll_migration.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gup-remove-foll_migration.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: David Hildenbrand <david@redhat.com>
Subject: mm/gup: remove FOLL_MIGRATION
Date: Fri, 21 Oct 2022 12:11:41 +0200
Fortunately, the last user (KSM) is gone, so let's just remove this rather
special code from generic GUP handling -- especially because KSM never
required the PMD handling as KSM only deals with individual base pages.
Link: https://lkml.kernel.org/r/20221021101141.84170-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mm.h | 1 -
mm/gup.c | 31 +++----------------------------
2 files changed, 3 insertions(+), 29 deletions(-)
--- a/include/linux/mm.h~mm-gup-remove-foll_migration
+++ a/include/linux/mm.h
@@ -2920,7 +2920,6 @@ struct page *follow_page(struct vm_area_
* and return without waiting upon it */
#define FOLL_NOFAULT 0x80 /* do not fault in pages */
#define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
-#define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */
#define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */
#define FOLL_ANON 0x8000 /* don't do file mappings */
--- a/mm/gup.c~mm-gup-remove-foll_migration
+++ a/mm/gup.c
@@ -533,30 +533,13 @@ static struct page *follow_page_pte(stru
if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
(FOLL_PIN | FOLL_GET)))
return ERR_PTR(-EINVAL);
-retry:
if (unlikely(pmd_bad(*pmd)))
return no_page_table(vma, flags);
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
pte = *ptep;
- if (!pte_present(pte)) {
- swp_entry_t entry;
- /*
- * KSM's break_ksm() relies upon recognizing a ksm page
- * even while it is being migrated, so for that case we
- * need migration_entry_wait().
- */
- if (likely(!(flags & FOLL_MIGRATION)))
- goto no_page;
- if (pte_none(pte))
- goto no_page;
- entry = pte_to_swp_entry(pte);
- if (!is_migration_entry(entry))
- goto no_page;
- pte_unmap_unlock(ptep, ptl);
- migration_entry_wait(mm, pmd, address);
- goto retry;
- }
+ if (!pte_present(pte))
+ goto no_page;
if (pte_protnone(pte) && !gup_can_follow_protnone(flags))
goto no_page;
@@ -688,18 +671,10 @@ retry:
if (pmd_protnone(pmdval) && !gup_can_follow_protnone(flags))
return no_page_table(vma, flags);
-retry_locked:
ptl = pmd_lock(mm, pmd);
- if (unlikely(pmd_none(*pmd))) {
- spin_unlock(ptl);
- return no_page_table(vma, flags);
- }
if (unlikely(!pmd_present(*pmd))) {
spin_unlock(ptl);
- if (likely(!(flags & FOLL_MIGRATION)))
- return no_page_table(vma, flags);
- pmd_migration_entry_wait(mm, pmd);
- goto retry_locked;
+ return no_page_table(vma, flags);
}
if (unlikely(!(pmd_trans_huge(*pmd) || pmd_devmap(pmdval)))) {
spin_unlock(ptl);
_
Patches currently in -mm which might be from david@redhat.com are
selftests-vm-anon_cow-test-cow-handling-of-anonymous-memory.patch
selftests-vm-factor-out-pagemap_is_populated-into-vm_util.patch
selftests-vm-anon_cow-thp-tests.patch
selftests-vm-anon_cow-hugetlb-tests.patch
selftests-vm-anon_cow-add-liburing-test-cases.patch
mm-gup_test-start-stop-read-functionality-for-pin-longterm-test.patch
mm-gup_test-start-stop-read-functionality-for-pin-longterm-test-fix.patch
selftests-vm-anon_cow-add-r-o-longterm-tests-via-gup_test.patch
selftests-vm-add-ksm-unmerge-tests.patch
mm-pagewalk-dont-trigger-test_walk-in-walk_page_vma.patch
selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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