* + mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch added to mm-unstable branch
@ 2026-09-16 22:48 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-09-16 22:48 UTC (permalink / raw)
To: mm-commits, kas, akpm
The patch titled
Subject: mm/khugepaged: count collapses where khugepaged makes them
has been added to the -mm mm-unstable branch. Its filename is
mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-count-collapses-where-khugepaged-makes-them.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 various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
Subject: mm/khugepaged: count collapses where khugepaged makes them
Date: Wed, 16 Sep 2026 10:31:29 +0100
collapse_single_pmd() bumps khugepaged_pages_collapsed for its caller, and
tests cc->is_khugepaged to know whether it should: the counter belongs to
the daemon, and MADV_COLLAPSE must not touch it.
The daemon sees every result of every collapse it asks for, so it can keep
its own counter without the shared path testing who called.
Assisted-by: LLM
Link: https://lore.kernel.org/20260916093145.4022188-3-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
---
mm/khugepaged.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
--- a/mm/khugepaged.c~mm-khugepaged-count-collapses-where-khugepaged-makes-them
+++ a/mm/khugepaged.c
@@ -2808,10 +2808,8 @@ static enum scan_result collapse_single_
mmap_assert_locked(mm);
- if (vma_is_anonymous(vma)) {
- result = collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
- goto end;
- }
+ if (vma_is_anonymous(vma))
+ return collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
file = get_file(vma->vm_file);
pgoff = linear_page_index(vma, addr);
@@ -2847,9 +2845,6 @@ retry:
result = SCAN_SUCCEED;
mmap_read_unlock(mm);
}
-end:
- if (cc->is_khugepaged && result == SCAN_SUCCEED)
- ++khugepaged_pages_collapsed;
return result;
}
@@ -2926,6 +2921,8 @@ static void collapse_scan_mm_slot(unsign
*result = collapse_single_pmd(khugepaged_scan.address,
vma, &lock_dropped, cc);
+ if (*result == SCAN_SUCCEED)
+ khugepaged_pages_collapsed++;
/* move to next address */
khugepaged_scan.address += HPAGE_PMD_SIZE;
if (lock_dropped)
_
Patches currently in -mm which might be from kas@kernel.org are
mm-huge_memory-do-not-touch-frozen-folios-in-deferred_split_isolate.patch
mm-huge_memory-dequeue-the-deferred-split-after-the-split-freeze.patch
mm-huge_memory-add-folio_reset_partially_mapped.patch
mm-khugepaged-drop-redundant-mm_struct-pin-in-madvise_collapse.patch
mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch
mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch
mm-collapse-add-collapseh-for-the-collapse-interface.patch
mm-collapse-state-what-a-collapse-may-do-in-the-policy.patch
mm-collapse-drop-the-collapse_possible-wrapper.patch
mm-collapse-name-the-per-table-scan-reset-for-what-it-resets.patch
mm-collapse-separate-scanning-a-pte-table-from-collapsing-it.patch
mm-collapse-open-code-collapse_single_pmd-in-its-two-callers.patch
mm-collapse-work-out-the-orders-a-vma-allows-once-per-vma.patch
mm-collapse-declare-the-collapse-interface-in-collapseh.patch
mm-collapse-implement-madv_collapse-in-madvisec.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch added to mm-unstable branch
@ 2026-09-28 22:01 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-09-28 22:01 UTC (permalink / raw)
To: mm-commits, kas, akpm
The patch titled
Subject: mm/khugepaged: count collapses where khugepaged makes them
has been added to the -mm mm-unstable branch. Its filename is
mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-count-collapses-where-khugepaged-makes-them.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 various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
Subject: mm/khugepaged: count collapses where khugepaged makes them
Date: Mon, 28 Sep 2026 11:06:16 +0100
collapse_single_pmd() bumps khugepaged_pages_collapsed for its caller, and
tests cc->is_khugepaged to know whether it should: the counter belongs to
the daemon, and MADV_COLLAPSE must not touch it.
The daemon sees every result of every collapse it asks for, so it can keep
its own counter without the shared path testing who called.
Link: https://lore.kernel.org/20260928100630.21870-3-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Assisted-by: LLM
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <nico.pache@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Jann Horn <jannh@google.com>
---
mm/khugepaged.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
--- a/mm/khugepaged.c~mm-khugepaged-count-collapses-where-khugepaged-makes-them
+++ a/mm/khugepaged.c
@@ -2838,10 +2838,8 @@ static enum scan_result collapse_single_
mmap_assert_locked(mm);
- if (vma_is_anonymous(vma)) {
- result = collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
- goto end;
- }
+ if (vma_is_anonymous(vma))
+ return collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
file = get_file(vma->vm_file);
pgoff = linear_page_index(vma, addr);
@@ -2877,9 +2875,6 @@ retry:
result = SCAN_SUCCEED;
mmap_read_unlock(mm);
}
-end:
- if (cc->is_khugepaged && result == SCAN_SUCCEED)
- ++khugepaged_pages_collapsed;
return result;
}
@@ -2956,6 +2951,8 @@ static void collapse_scan_mm_slot(unsign
*result = collapse_single_pmd(khugepaged_scan.address,
vma, &lock_dropped, cc);
+ if (*result == SCAN_SUCCEED)
+ khugepaged_pages_collapsed++;
/* move to next address */
khugepaged_scan.address += HPAGE_PMD_SIZE;
if (lock_dropped)
_
Patches currently in -mm which might be from kas@kernel.org are
mm-huge_memory-do-not-touch-frozen-folios-in-deferred_split_isolate.patch
mm-huge_memory-dequeue-the-deferred-split-after-the-split-freeze.patch
mm-huge_memory-add-folio_reset_partially_mapped.patch
mm-khugepaged-drop-redundant-mm_struct-pin-in-madvise_collapse.patch
mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch
mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch
mm-collapse-add-collapseh-for-the-collapse-interface.patch
mm-collapse-state-what-a-collapse-may-do-in-the-policy.patch
mm-collapse-drop-the-collapse_possible-wrapper.patch
mm-collapse-name-the-per-table-scan-reset-for-what-it-resets.patch
mm-collapse-call-collapse_file-from-collapse_single_pmd.patch
mm-collapse-separate-scanning-a-pte-table-from-collapsing-it.patch
mm-collapse-open-code-collapse_single_pmd-in-its-two-callers.patch
mm-collapse-work-out-the-orders-a-vma-allows-once-per-vma.patch
mm-collapse-declare-the-collapse-interface-in-collapseh.patch
mm-collapse-implement-madv_collapse-in-madvisec.patch
selftests-mm-raise-the-khugepaged-test-case-cap.patch
selftests-mm-skip-collapse_compound_extreme-where-the-pmd-is-too-large.patch
selftests-mm-scale-khugepageds-collapse-wait-with-the-pmd-size.patch
selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.patch
selftests-mm-make-the-swap-cases-swapout-reliable.patch
selftests-mm-stop-khugepaged-during-the-madv_collapse-cases.patch
selftests-mm-move-is_backed_by_folio-into-vm_util.patch
selftests-mm-add-folio-order-check-for-address-ranges.patch
selftests-mm-add-folio-order-detection-self-check.patch
selftests-mm-add-khugepaged-completion-barrier-helper.patch
selftests-mm-add-order-parameterized-khugepaged-collapse-cases.patch
selftests-mm-parameterize-the-mixed-source-collapse-case-by-source-order.patch
selftests-mm-cover-a-shared-source-collapse-write-race.patch
selftests-mm-run-every-supported-collapse-order-by-default.patch
selftests-mm-check-that-one-khugepaged-pass-collapses-one-window.patch
selftests-mm-add-khugepaged-race-harness.patch
selftests-mm-race-the-collapse-of-windows-with-holes.patch
selftests-mm-add-memory-pressure-threads-to-the-khugepaged-race-harness.patch
selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.patch
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