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selftests/vm: add MADV_COLLAPSE collapse context to selftests

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Add madvise collapse context to hugepage collapse selftests.  This context
is tested with /sys/kernel/mm/transparent_hugepage/enabled set to "never"
in order to avoid unwanted interaction with khugepaged during testing.

Also, refactor updates to sysfs THP settings using a stack so that the THP
settings from nested callers can be restored.

Link: https://lkml.kernel.org/r/20220706235936.2197195-17-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pavel Begunkov <asml.silence@gmail.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: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Souptick Joarder (HPE)" <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Zach O'Keefe 2022-07-06 16:59:34 -07:00 committed by Andrew Morton
parent be6667b0db
commit 9330694de5
1 changed files with 124 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

169
tools/testing/selftests/vm/khugepaged.c
View File

@ -14,6 +14,9 @@
#ifndef MADV_PAGEOUT
#define MADV_PAGEOUT 21
#endif
#ifndef MADV_COLLAPSE
#define MADV_COLLAPSE 25
#endif
#define BASE_ADDR ((void *)(1UL << 30))
static unsigned long hpage_pmd_size;
@ -95,18 +98,6 @@ struct settings {
struct khugepaged_settings khugepaged;
};
static struct settings default_settings = {
.thp_enabled = THP_MADVISE,
.thp_defrag = THP_DEFRAG_ALWAYS,
.shmem_enabled = SHMEM_NEVER,
.use_zero_page = 0,
.khugepaged = {
.defrag = 1,
.alloc_sleep_millisecs = 10,
.scan_sleep_millisecs = 10,
},
};
static struct settings saved_settings;
static bool skip_settings_restore;
@ -284,6 +275,39 @@ static void write_settings(struct settings *settings)
write_num("khugepaged/pages_to_scan", khugepaged->pages_to_scan);
}
#define MAX_SETTINGS_DEPTH 4
static struct settings settings_stack[MAX_SETTINGS_DEPTH];
static int settings_index;
static struct settings *current_settings(void)
{
if (!settings_index) {
printf("Fail: No settings set");
exit(EXIT_FAILURE);
}
return settings_stack + settings_index - 1;
}
static void push_settings(struct settings *settings)
{
if (settings_index >= MAX_SETTINGS_DEPTH) {
printf("Fail: Settings stack exceeded");
exit(EXIT_FAILURE);
}
settings_stack[settings_index++] = *settings;
write_settings(current_settings());
}
static void pop_settings(void)
{
if (settings_index <= 0) {
printf("Fail: Settings stack empty");
exit(EXIT_FAILURE);
}
--settings_index;
write_settings(current_settings());
}
static void restore_settings(int sig)
{
if (skip_settings_restore)
@ -327,14 +351,6 @@ static void save_settings(void)
signal(SIGQUIT, restore_settings);
}
static void adjust_settings(void)
{
printf("Adjust settings...");
write_settings(&default_settings);
success("OK");
}
#define MAX_LINE_LENGTH 500
static bool check_for_pattern(FILE *fp, char *pattern, char *buf)
@ -493,6 +509,38 @@ static void validate_memory(int *p, unsigned long start, unsigned long end)
}
}
static void madvise_collapse(const char *msg, char *p, bool expect)
{
int ret;
struct settings settings = *current_settings();
printf("%s...", msg);
/* Sanity check */
if (check_huge(p)) {
printf("Unexpected huge page\n");
exit(EXIT_FAILURE);
}
/*
* Prevent khugepaged interference and tests that MADV_COLLAPSE
* ignores /sys/kernel/mm/transparent_hugepage/enabled
*/
settings.thp_enabled = THP_NEVER;
push_settings(&settings);
/* Clear VM_NOHUGEPAGE */
madvise(p, hpage_pmd_size, MADV_HUGEPAGE);
ret = madvise(p, hpage_pmd_size, MADV_COLLAPSE);
if (((bool)ret) == expect)
fail("Fail: Bad return value");
else if (check_huge(p) != expect)
fail("Fail: check_huge()");
else
success("OK");
pop_settings();
}
#define TICK 500000
static bool wait_for_scan(const char *msg, char *p)
{
@ -542,11 +590,11 @@ static void khugepaged_collapse(const char *msg, char *p, bool expect)
static void alloc_at_fault(void)
{
struct settings settings = default_settings;
struct settings settings = *current_settings();
char *p;
settings.thp_enabled = THP_ALWAYS;
write_settings(&settings);
push_settings(&settings);
p = alloc_mapping();
*p = 1;
@ -556,7 +604,7 @@ static void alloc_at_fault(void)
else
fail("Fail");
write_settings(&default_settings);
pop_settings();
madvise(p, page_size, MADV_DONTNEED);
printf("Split huge PMD on MADV_DONTNEED...");
@ -602,11 +650,11 @@ static void collapse_single_pte_entry(struct collapse_context *c)
static void collapse_max_ptes_none(struct collapse_context *c)
{
int max_ptes_none = hpage_pmd_nr / 2;
struct settings settings = default_settings;
struct settings settings = *current_settings();
void *p;
settings.khugepaged.max_ptes_none = max_ptes_none;
write_settings(&settings);
push_settings(&settings);
p = alloc_mapping();
@ -623,7 +671,7 @@ static void collapse_max_ptes_none(struct collapse_context *c)
}
munmap(p, hpage_pmd_size);
write_settings(&default_settings);
pop_settings();
}
static void collapse_swapin_single_pte(struct collapse_context *c)
@ -703,7 +751,6 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c)
p = alloc_hpage();
madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
printf("Split huge page leaving single PTE mapping compound page...");
madvise(p + page_size, hpage_pmd_size - page_size, MADV_DONTNEED);
if (!check_huge(p))
@ -864,7 +911,7 @@ static void collapse_fork_compound(struct collapse_context *c)
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);
current_settings()->khugepaged.max_ptes_shared);
validate_memory(p, 0, hpage_pmd_size);
munmap(p, hpage_pmd_size);
@ -943,9 +990,21 @@ static void collapse_max_ptes_shared(struct collapse_context *c)
munmap(p, hpage_pmd_size);
}
int main(void)
int main(int argc, const char **argv)
{
struct collapse_context c;
struct settings default_settings = {
.thp_enabled = THP_MADVISE,
.thp_defrag = THP_DEFRAG_ALWAYS,
.shmem_enabled = SHMEM_NEVER,
.use_zero_page = 0,
.khugepaged = {
.defrag = 1,
.alloc_sleep_millisecs = 10,
.scan_sleep_millisecs = 10,
},
};
const char *tests = argc == 1 ? "all" : argv[1];
setbuf(stdout, NULL);
@ -959,26 +1018,46 @@ int main(void)
default_settings.khugepaged.pages_to_scan = hpage_pmd_nr * 8;
save_settings();
adjust_settings();
push_settings(&default_settings);
alloc_at_fault();
printf("\n*** Testing context: khugepaged ***\n");
c.collapse = &khugepaged_collapse;
c.enforce_pte_scan_limits = true;
if (!strcmp(tests, "khugepaged") || !strcmp(tests, "all")) {
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);
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);
}
if (!strcmp(tests, "madvise") || !strcmp(tests, "all")) {
printf("\n*** Testing context: madvise ***\n");
c.collapse = &madvise_collapse;
c.enforce_pte_scan_limits = false;
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);
}