+ selftests-mm-kugepaged-restore-thp-settings-at-exit.patch added to mm-unstable branch

+ selftests-mm-kugepaged-restore-thp-settings-at-exit.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: selftests/mm/kugepaged: restore thp settings at exit
has been added to the -mm mm-unstable branch.  Its filename is
     selftests-mm-kugepaged-restore-thp-settings-at-exit.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-kugepaged-restore-thp-settings-at-exit.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: Ryan Roberts <ryan.roberts@arm.com>
Subject: selftests/mm/kugepaged: restore thp settings at exit
Date: Thu, 7 Dec 2023 16:12:06 +0000

Previously, the saved thp settings would be restored upon a signal or at
the natural end of the test suite.  But there are some tests that directly
call exit() upon failure.  In this case, the thp settings were not being
restored, which could then influence other tests.

Fix this by installing an atexit() handler to do the actual restore.  The
signal handler can now just call exit() and the atexit handler is invoked.

Link: https://lkml.kernel.org/r/20231207161211.2374093-6-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/mm/khugepaged.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

--- a/tools/testing/selftests/mm/khugepaged.c~selftests-mm-kugepaged-restore-thp-settings-at-exit
+++ a/tools/testing/selftests/mm/khugepaged.c
@@ -374,18 +374,22 @@ static void pop_settings(void)
 	write_settings(current_settings());
 }
 
-static void restore_settings(int sig)
+static void restore_settings_atexit(void)
 {
 	if (skip_settings_restore)
-		goto out;
+		return;
 
 	printf("Restore THP and khugepaged settings...");
 	write_settings(&saved_settings);
 	success("OK");
-	if (sig)
-		exit(EXIT_FAILURE);
-out:
-	exit(exit_status);
+
+	skip_settings_restore = true;
+}
+
+static void restore_settings(int sig)
+{
+	/* exit() will invoke the restore_settings_atexit handler. */
+	exit(sig ? EXIT_FAILURE : exit_status);
 }
 
 static void save_settings(void)
@@ -415,6 +419,7 @@ static void save_settings(void)
 
 	success("OK");
 
+	atexit(restore_settings_atexit);
 	signal(SIGTERM, restore_settings);
 	signal(SIGINT, restore_settings);
 	signal(SIGHUP, restore_settings);
_

Patches currently in -mm which might be from ryan.roberts@arm.com are

mm-readahead-do-not-allow-order-1-folio.patch
mm-allow-deferred-splitting-of-arbitrary-anon-large-folios.patch
mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.patch
mm-thp-introduce-multi-size-thp-sysfs-interface.patch
mm-thp-support-allocation-of-anonymous-multi-size-thp.patch
selftests-mm-kugepaged-restore-thp-settings-at-exit.patch
selftests-mm-factor-out-thp-settings-management.patch
selftests-mm-support-multi-size-thp-interface-in-thp_settings.patch
selftests-mm-khugepaged-enlighten-for-multi-size-thp.patch
selftests-mm-cow-generalize-do_run_with_thp-helper.patch
selftests-mm-cow-add-tests-for-anonymous-multi-size-thp.patch