The patch titled
Subject: selftests/vm: modularize collapse selftests
has been added to the -mm mm-unstable branch. Its filename is
selftests-vm-modularize-collapse-selftests.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-vm-modularize-collapse-selftests.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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and is updated there every 2-3 working days
------------------------------------------------------
From: "Zach O'Keefe" <zokeefe@xxxxxxxxxx>
Subject: selftests/vm: modularize collapse selftests
Date: Wed, 6 Jul 2022 16:59:32 -0700
Modularize the collapse action of khugepaged collapse selftests by
introducing a struct collapse_context which specifies how to collapse a
given memory range and the expected semantics of the collapse. This can
be reused later to test other collapse contexts.
Additionally, all tests have logic that checks if a collapse occurred via
reading /proc/self/smaps, and report if this is different than expected.
Move this logic into the per-context ->collapse() hook instead of
repeating it in every test.
Link: https://lkml.kernel.org/r/20220706235936.2197195-15-zokeefe@xxxxxxxxxx
Signed-off-by: Zach O'Keefe <zokeefe@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: David Rientjes <rientjes@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>
---
tools/testing/selftests/vm/khugepaged.c | 247 +++++++++-------------
1 file changed, 108 insertions(+), 139 deletions(-)
--- a/tools/testing/selftests/vm/khugepaged.c~selftests-vm-modularize-collapse-selftests
+++ a/tools/testing/selftests/vm/khugepaged.c
@@ -23,6 +23,11 @@ static int hpage_pmd_nr;
#define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/"
#define PID_SMAPS "/proc/self/smaps"
+struct collapse_context {
+ void (*collapse)(const char *msg, char *p, bool expect);
+ bool enforce_pte_scan_limits;
+};
+
enum thp_enabled {
THP_ALWAYS,
THP_MADVISE,
@@ -501,6 +506,21 @@ static bool wait_for_scan(const char *ms
return timeout == -1;
}
+static void khugepaged_collapse(const char *msg, char *p, bool expect)
+{
+ if (wait_for_scan(msg, p)) {
+ if (expect)
+ fail("Timeout");
+ else
+ success("OK");
+ return;
+ } else if (check_huge(p) == expect) {
+ success("OK");
+ } else {
+ fail("Fail");
+ }
+}
+
static void alloc_at_fault(void)
{
struct settings settings = default_settings;
@@ -528,53 +548,39 @@ static void alloc_at_fault(void)
munmap(p, hpage_pmd_size);
}
-static void collapse_full(void)
+static void collapse_full(struct collapse_context *c)
{
void *p;
p = alloc_mapping();
fill_memory(p, 0, hpage_pmd_size);
- if (wait_for_scan("Collapse fully populated PTE table", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse fully populated PTE table", p, true);
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
}
-static void collapse_empty(void)
+static void collapse_empty(struct collapse_context *c)
{
void *p;
p = alloc_mapping();
- if (wait_for_scan("Do not collapse empty PTE table", p))
- fail("Timeout");
- else if (check_huge(p))
- fail("Fail");
- else
- success("OK");
+ c->collapse("Do not collapse empty PTE table", p, false);
munmap(p, hpage_pmd_size);
}
-static void collapse_single_pte_entry(void)
+static void collapse_single_pte_entry(struct collapse_context *c)
{
void *p;
p = alloc_mapping();
fill_memory(p, 0, page_size);
- if (wait_for_scan("Collapse PTE table with single PTE entry present", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table with single PTE entry present", p,
+ true);
validate_memory(p, 0, page_size);
munmap(p, hpage_pmd_size);
}
-static void collapse_max_ptes_none(void)
+static void collapse_max_ptes_none(struct collapse_context *c)
{
int max_ptes_none = hpage_pmd_nr / 2;
struct settings settings = default_settings;
@@ -586,28 +592,22 @@ static void collapse_max_ptes_none(void)
p = alloc_mapping();
fill_memory(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size);
- if (wait_for_scan("Do not collapse with max_ptes_none exceeded", p))
- fail("Timeout");
- else if (check_huge(p))
- fail("Fail");
- else
- success("OK");
+ c->collapse("Maybe collapse with max_ptes_none exceeded", p,
+ !c->enforce_pte_scan_limits);
validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size);
- fill_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size);
- if (wait_for_scan("Collapse with max_ptes_none PTEs empty", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
- validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size);
+ if (c->enforce_pte_scan_limits) {
+ fill_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size);
+ c->collapse("Collapse with max_ptes_none PTEs empty", p, true);
+ validate_memory(p, 0,
+ (hpage_pmd_nr - max_ptes_none) * page_size);
+ }
munmap(p, hpage_pmd_size);
write_settings(&default_settings);
}
-static void collapse_swapin_single_pte(void)
+static void collapse_swapin_single_pte(struct collapse_context *c)
{
void *p;
p = alloc_mapping();
@@ -625,18 +625,13 @@ static void collapse_swapin_single_pte(v
goto out;
}
- if (wait_for_scan("Collapse with swapping in single PTE entry", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse with swapping in single PTE entry", p, true);
validate_memory(p, 0, hpage_pmd_size);
out:
munmap(p, hpage_pmd_size);
}
-static void collapse_max_ptes_swap(void)
+static void collapse_max_ptes_swap(struct collapse_context *c)
{
int max_ptes_swap = read_num("khugepaged/max_ptes_swap");
void *p;
@@ -656,39 +651,34 @@ static void collapse_max_ptes_swap(void)
goto out;
}
- if (wait_for_scan("Do not collapse with max_ptes_swap exceeded", p))
- fail("Timeout");
- else if (check_huge(p))
- fail("Fail");
- else
- success("OK");
+ c->collapse("Maybe collapse with max_ptes_swap exceeded", p,
+ !c->enforce_pte_scan_limits);
validate_memory(p, 0, hpage_pmd_size);
- fill_memory(p, 0, hpage_pmd_size);
- printf("Swapout %d of %d pages...", max_ptes_swap, hpage_pmd_nr);
- if (madvise(p, max_ptes_swap * page_size, MADV_PAGEOUT)) {
- perror("madvise(MADV_PAGEOUT)");
- exit(EXIT_FAILURE);
- }
- if (check_swap(p, max_ptes_swap * page_size)) {
- success("OK");
- } else {
- fail("Fail");
- goto out;
- }
+ if (c->enforce_pte_scan_limits) {
+ fill_memory(p, 0, hpage_pmd_size);
+ printf("Swapout %d of %d pages...", max_ptes_swap,
+ hpage_pmd_nr);
+ if (madvise(p, max_ptes_swap * page_size, MADV_PAGEOUT)) {
+ perror("madvise(MADV_PAGEOUT)");
+ exit(EXIT_FAILURE);
+ }
+ if (check_swap(p, max_ptes_swap * page_size)) {
+ success("OK");
+ } else {
+ fail("Fail");
+ goto out;
+ }
- if (wait_for_scan("Collapse with max_ptes_swap pages swapped out", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
- validate_memory(p, 0, hpage_pmd_size);
+ c->collapse("Collapse with max_ptes_swap pages swapped out", p,
+ true);
+ validate_memory(p, 0, hpage_pmd_size);
+ }
out:
munmap(p, hpage_pmd_size);
}
-static void collapse_single_pte_entry_compound(void)
+static void collapse_single_pte_entry_compound(struct collapse_context *c)
{
void *p;
@@ -710,17 +700,13 @@ static void collapse_single_pte_entry_co
else
fail("Fail");
- if (wait_for_scan("Collapse PTE table with single PTE mapping compound page", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table with single PTE mapping compound page",
+ p, true);
validate_memory(p, 0, page_size);
munmap(p, hpage_pmd_size);
}
-static void collapse_full_of_compound(void)
+static void collapse_full_of_compound(struct collapse_context *c)
{
void *p;
@@ -742,17 +728,12 @@ static void collapse_full_of_compound(vo
else
fail("Fail");
- if (wait_for_scan("Collapse PTE table full of compound pages", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table full of compound pages", p, true);
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
}
-static void collapse_compound_extreme(void)
+static void collapse_compound_extreme(struct collapse_context *c)
{
void *p;
int i;
@@ -798,18 +779,14 @@ static void collapse_compound_extreme(vo
else
fail("Fail");
- if (wait_for_scan("Collapse PTE table full of different compound pages", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table full of different compound pages", p,
+ true);
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
}
-static void collapse_fork(void)
+static void collapse_fork(struct collapse_context *c)
{
int wstatus;
void *p;
@@ -835,13 +812,8 @@ static void collapse_fork(void)
fail("Fail");
fill_memory(p, page_size, 2 * page_size);
-
- if (wait_for_scan("Collapse PTE table with single page shared with parent process", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table with single page shared with parent process",
+ p, true);
validate_memory(p, 0, page_size);
munmap(p, hpage_pmd_size);
@@ -860,7 +832,7 @@ static void collapse_fork(void)
munmap(p, hpage_pmd_size);
}
-static void collapse_fork_compound(void)
+static void collapse_fork_compound(struct collapse_context *c)
{
int wstatus;
void *p;
@@ -896,14 +868,10 @@ static void collapse_fork_compound(void)
fill_memory(p, 0, page_size);
write_num("khugepaged/max_ptes_shared", hpage_pmd_nr - 1);
- if (wait_for_scan("Collapse PTE table full of compound pages in child", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse PTE table full of compound pages in child",
+ p, true);
write_num("khugepaged/max_ptes_shared",
- default_settings.khugepaged.max_ptes_shared);
+ default_settings.khugepaged.max_ptes_shared);
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
@@ -922,7 +890,7 @@ static void collapse_fork_compound(void)
munmap(p, hpage_pmd_size);
}
-static void collapse_max_ptes_shared()
+static void collapse_max_ptes_shared(struct collapse_context *c)
{
int max_ptes_shared = read_num("khugepaged/max_ptes_shared");
int wstatus;
@@ -957,28 +925,22 @@ static void collapse_max_ptes_shared()
else
fail("Fail");
- if (wait_for_scan("Do not collapse with max_ptes_shared exceeded", p))
- fail("Timeout");
- else if (!check_huge(p))
- success("OK");
- else
- fail("Fail");
-
- printf("Trigger CoW on page %d of %d...",
- hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
- fill_memory(p, 0, (hpage_pmd_nr - max_ptes_shared) * page_size);
- if (!check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Maybe collapse with max_ptes_shared exceeded", p,
+ !c->enforce_pte_scan_limits);
+ if (c->enforce_pte_scan_limits) {
+ printf("Trigger CoW on page %d of %d...",
+ hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
+ fill_memory(p, 0, (hpage_pmd_nr - max_ptes_shared) *
+ page_size);
+ if (!check_huge(p))
+ success("OK");
+ else
+ fail("Fail");
- if (wait_for_scan("Collapse with max_ptes_shared PTEs shared", p))
- fail("Timeout");
- else if (check_huge(p))
- success("OK");
- else
- fail("Fail");
+ c->collapse("Collapse with max_ptes_shared PTEs shared",
+ p, true);
+ }
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
@@ -999,6 +961,8 @@ static void collapse_max_ptes_shared()
int main(void)
{
+ struct collapse_context c;
+
setbuf(stdout, NULL);
page_size = getpagesize();
@@ -1014,18 +978,23 @@ int main(void)
adjust_settings();
alloc_at_fault();
- collapse_full();
- collapse_empty();
- collapse_single_pte_entry();
- collapse_max_ptes_none();
- collapse_swapin_single_pte();
- collapse_max_ptes_swap();
- collapse_single_pte_entry_compound();
- collapse_full_of_compound();
- collapse_compound_extreme();
- collapse_fork();
- collapse_fork_compound();
- collapse_max_ptes_shared();
+
+ printf("\n*** Testing context: khugepaged ***\n");
+ c.collapse = &khugepaged_collapse;
+ c.enforce_pte_scan_limits = true;
+
+ collapse_full(&c);
+ collapse_empty(&c);
+ collapse_single_pte_entry(&c);
+ collapse_max_ptes_none(&c);
+ collapse_swapin_single_pte(&c);
+ collapse_max_ptes_swap(&c);
+ collapse_single_pte_entry_compound(&c);
+ collapse_full_of_compound(&c);
+ collapse_compound_extreme(&c);
+ collapse_fork(&c);
+ collapse_fork_compound(&c);
+ collapse_max_ptes_shared(&c);
restore_settings(0);
}
_
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
