* + selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch added to mm-unstable branch
@ 2022-09-07 22:20 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2022-09-07 22:20 UTC (permalink / raw)
To: mm-commits, willy, vbabka, songliubraving, sj, shy828301,
rongwei.wang, rientjes, peterx, pasha.tatashin, minchan,
linmiaohe, kirill.shutemov, jthoughton, hughd, david, ckennelly,
axelrasmussen, zokeefe, akpm
The patch titled
Subject: selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
has been added to the -mm mm-unstable branch. Its filename is
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.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
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*** 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: "Zach O'Keefe" <zokeefe@google.com>
Subject: selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
Date: Wed, 7 Sep 2022 07:45:20 -0700
This test tests that MADV_COLLAPSE acting on file/shmem memory for which
(1) the file extent mapping by the memory is already a huge page in the
page cache, and (2) the pmd mapping this memory in the target process is
none.
In practice, (1)+(2) is the state left over after khugepaged has
successfully collapsed file/shmem memory for a target VMA, but the memory
has not yet been refaulted. So, this test in-effect tests MADV_COLLAPSE
racing with khugepaged to collapse the memory first.
Link: https://lkml.kernel.org/r/20220907144521.3115321-10-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
tools/testing/selftests/vm/khugepaged.c | 30 ++++++++++++++++++++++
1 file changed, 30 insertions(+)
--- a/tools/testing/selftests/vm/khugepaged.c~selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd
+++ a/tools/testing/selftests/vm/khugepaged.c
@@ -1323,6 +1323,33 @@ static void madvise_collapse_existing_th
ops->cleanup_area(p, hpage_pmd_size);
}
+/*
+ * Test race with khugepaged where page tables have been retracted and
+ * pmd cleared.
+ */
+static void madvise_retracted_page_tables(struct collapse_context *c,
+ struct mem_ops *ops)
+{
+ void *p;
+ int nr_hpages = 1;
+ unsigned long size = nr_hpages * hpage_pmd_size;
+
+ p = ops->setup_area(nr_hpages);
+ ops->fault(p, 0, size);
+
+ /* Let khugepaged collapse and leave pmd cleared */
+ if (wait_for_scan("Collapse and leave PMD cleared", p, nr_hpages,
+ ops)) {
+ fail("Timeout");
+ return;
+ }
+ success("OK");
+ c->collapse("Install huge PMD from page cache", p, nr_hpages, ops,
+ true);
+ validate_memory(p, 0, size);
+ ops->cleanup_area(p, size);
+}
+
static void usage(void)
{
fprintf(stderr, "\nUsage: ./khugepaged <test type> [dir]\n\n");
@@ -1494,5 +1521,8 @@ int main(int argc, const char **argv)
TEST(madvise_collapse_existing_thps, madvise_context, file_ops);
TEST(madvise_collapse_existing_thps, madvise_context, shmem_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, file_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);
+
restore_settings(0);
}
_
Patches currently in -mm which might be from zokeefe@google.com are
mm-khugepaged-add-struct-collapse_control.patch
mm-khugepaged-add-struct-collapse_control-fix.patch
mm-khugepaged-add-struct-collapse_control-fix-fix-fix.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-add-flag-to-predicate-khugepaged-only-behavior-fix.patch
mm-khugepaged-record-scan_pmd_mapped-when-scan_pmd-finds-hugepage.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-2.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-3.patch
mm-khugepaged-rename-prefix-of-shared-collapse-functions.patch
mm-madvise-add-madv_collapse-to-process_madvise.patch
mm-madvise-add-madv_collapse-to-process_madvise-fix.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
mm-shmem-add-flag-to-enforce-shmem-thp-in-hugepage_vma_check.patch
mm-khugepaged-attempt-to-map-file-shmem-backed-pte-mapped-thps-by-pmds.patch
mm-madvise-add-file-and-shmem-support-to-madv_collapse.patch
mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch
selftests-vm-dedup-thp-helpers.patch
selftests-vm-modularize-thp-collapse-memory-operations.patch
selftests-vm-add-thp-collapse-file-and-tmpfs-testing.patch
selftests-vm-add-thp-collapse-shmem-testing.patch
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
selftests-vm-add-selftest-for-madv_collapse-of-uffd-minor-memory.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch added to mm-unstable branch
@ 2022-09-25 19:13 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2022-09-25 19:13 UTC (permalink / raw)
To: mm-commits, willy, vbabka, songliubraving, sj, shy828301,
rongwei.wang, rientjes, peterx, pasha.tatashin, minchan,
linmiaohe, kirill.shutemov, jthoughton, hughd, david, ckennelly,
axelrasmussen, zokeefe, akpm
The patch titled
Subject: selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
has been added to the -mm mm-unstable branch. Its filename is
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.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: "Zach O'Keefe" <zokeefe@google.com>
Subject: selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
Date: Thu, 22 Sep 2022 15:40:45 -0700
This test tests that MADV_COLLAPSE acting on file/shmem memory for which
(1) the file extent mapping by the memory is already a huge page in the
page cache, and (2) the pmd mapping this memory in the target process is
none.
In practice, (1)+(2) is the state left over after khugepaged has
successfully collapsed file/shmem memory for a target VMA, but the memory
has not yet been refaulted. So, this test in-effect tests MADV_COLLAPSE
racing with khugepaged to collapse the memory first.
Link: https://lkml.kernel.org/r/20220907144521.3115321-10-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220922224046.1143204-10-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
--- a/tools/testing/selftests/vm/khugepaged.c~selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd
+++ a/tools/testing/selftests/vm/khugepaged.c
@@ -1353,6 +1353,33 @@ static void madvise_collapse_existing_th
ops->cleanup_area(p, hpage_pmd_size);
}
+/*
+ * Test race with khugepaged where page tables have been retracted and
+ * pmd cleared.
+ */
+static void madvise_retracted_page_tables(struct collapse_context *c,
+ struct mem_ops *ops)
+{
+ void *p;
+ int nr_hpages = 1;
+ unsigned long size = nr_hpages * hpage_pmd_size;
+
+ p = ops->setup_area(nr_hpages);
+ ops->fault(p, 0, size);
+
+ /* Let khugepaged collapse and leave pmd cleared */
+ if (wait_for_scan("Collapse and leave PMD cleared", p, nr_hpages,
+ ops)) {
+ fail("Timeout");
+ return;
+ }
+ success("OK");
+ c->collapse("Install huge PMD from page cache", p, nr_hpages, ops,
+ true);
+ validate_memory(p, 0, size);
+ ops->cleanup_area(p, size);
+}
+
static void usage(void)
{
fprintf(stderr, "\nUsage: ./khugepaged <test type> [dir]\n\n");
@@ -1524,5 +1551,8 @@ int main(int argc, const char **argv)
TEST(madvise_collapse_existing_thps, madvise_context, file_ops);
TEST(madvise_collapse_existing_thps, madvise_context, shmem_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, file_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);
+
restore_settings(0);
}
_
Patches currently in -mm which might be from zokeefe@google.com are
mm-khugepaged-check-compound_order-in-collapse_pte_mapped_thp.patch
mm-madvise-madv_collapse-return-eagain-when-page-cannot-be-isolated.patch
selftests-vm-retry-on-eagain-for-madv_collapse-selftest.patch
mm-shmem-add-flag-to-enforce-shmem-thp-in-hugepage_vma_check.patch
mm-khugepaged-attempt-to-map-file-shmem-backed-pte-mapped-thps-by-pmds.patch
mm-madvise-add-file-and-shmem-support-to-madv_collapse.patch
mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch
selftests-vm-dedup-thp-helpers.patch
selftests-vm-modularize-thp-collapse-memory-operations.patch
selftests-vm-add-thp-collapse-file-and-tmpfs-testing.patch
selftests-vm-add-thp-collapse-shmem-testing.patch
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
selftests-vm-add-selftest-for-madv_collapse-of-uffd-minor-memory.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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