The patch titled
Subject: mm/madvise: add MADV_COLLAPSE to process_madvise()
has been added to the -mm mm-unstable branch. Its filename is
mm-madvise-add-madv_collapse-to-process_madvise.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-madvise-add-madv_collapse-to-process_madvise.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Zach O'Keefe" <zokeefe@xxxxxxxxxx>
Subject: mm/madvise: add MADV_COLLAPSE to process_madvise()
Date: Wed, 6 Jul 2022 16:59:30 -0700
Allow MADV_COLLAPSE behavior for process_madvise(2) if caller has
CAP_SYS_ADMIN or is requesting collapse of it's own memory.
This is useful for the development of userspace agents that seek to
optimize THP utilization system-wide by using userspace signals to
prioritize what memory is most deserving of being THP-backed.
Link: https://lkml.kernel.org/r/20220706235936.2197195-13-zokeefe@xxxxxxxxxx
Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Chris Kennelly <ckennelly@xxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Pavel Begunkov <asml.silence@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Rongwei Wang <rongwei.wang@xxxxxxxxxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/madvise.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/madvise.c~mm-madvise-add-madv_collapse-to-process_madvise
+++ a/mm/madvise.c
@@ -1171,13 +1171,15 @@ madvise_behavior_valid(int behavior)
}
static bool
-process_madvise_behavior_valid(int behavior)
+process_madvise_behavior_valid(int behavior, struct task_struct *task)
{
switch (behavior) {
case MADV_COLD:
case MADV_PAGEOUT:
case MADV_WILLNEED:
return true;
+ case MADV_COLLAPSE:
+ return task == current || capable(CAP_SYS_ADMIN);
default:
return false;
}
@@ -1455,7 +1457,7 @@ SYSCALL_DEFINE5(process_madvise, int, pi
goto free_iov;
}
- if (!process_madvise_behavior_valid(behavior)) {
+ if (!process_madvise_behavior_valid(behavior, task)) {
ret = -EINVAL;
goto release_task;
}
_
Patches currently in -mm which might be from zokeefe@xxxxxxxxxx are
mm-khugepaged-remove-redundant-transhuge_vma_suitable-check.patch
mm-khugepaged-add-struct-collapse_control.patch
mm-khugepaged-dedup-and-simplify-hugepage-alloc-and-charging.patch
mm-khugepaged-pipe-enum-scan_result-codes-back-to-callers.patch
mm-khugepaged-add-flag-to-predicate-khugepaged-only-behavior.patch
mm-thp-add-flag-to-enforce-sysfs-thp-in-hugepage_vma_check.patch
mm-khugepaged-record-scan_pmd_mapped-when-scan_pmd-finds-hugepage.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse.patch
mm-khugepaged-rename-prefix-of-shared-collapse-functions.patch
mm-madvise-add-huge_memory-mm_madvise_collapse-tracepoint.patch
mm-madvise-add-madv_collapse-to-process_madvise.patch
proc-smaps-add-pmdmappable-field-to-smaps.patch
selftests-vm-modularize-collapse-selftests.patch
selftests-vm-dedup-hugepage-allocation-logic.patch
selftests-vm-add-madv_collapse-collapse-context-to-selftests.patch
selftests-vm-add-selftest-to-verify-recollapse-of-thps.patch
selftests-vm-add-selftest-to-verify-multi-thp-collapse.patch
