+ selftests-vm-add-thp-collapse-shmem-testing-fix.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/vm: fix "add thp collapse file and tmpfs testing" for tmpfs
has been added to the -mm mm-unstable branch.  Its filename is
     selftests-vm-add-thp-collapse-shmem-testing-fix.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-thp-collapse-shmem-testing-fix.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@google.com>
Subject: selftests/vm: fix "add thp collapse file and tmpfs testing" for tmpfs
Date: Tue, 13 Sep 2022 14:25:17 -0700

In write_settings() and save_settings() we properly only read/write
/sys/block/<device>/queue/read_ahead_kb if the test file is not backed by
tmpfs.  However, in get_finfo(), we unconditionally attempt to resolve the
major/minor device pair and search for device interface, which we fail to
do when the device is the null device (major 0), as is the case when
stat(2)'ing a tmpfs-backed file.

Only resolve path to queue/read_ahead_kb when dealing with non-tmpfs
files.

Link: https://lkml.kernel.org/r/20220913212517.3163701-1-zokeefe@google.com
Fixes: 64b9fb1fa904 ("selftests/vm: add thp collapse file and tmpfs testing")
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/vm/khugepaged.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/tools/testing/selftests/vm/khugepaged.c~selftests-vm-add-thp-collapse-shmem-testing-fix
+++ a/tools/testing/selftests/vm/khugepaged.c
@@ -453,6 +453,8 @@ static void get_finfo(const char *dir)
 		exit(EXIT_FAILURE);
 	}
 	finfo.type = fs.f_type == TMPFS_MAGIC ? VMA_SHMEM : VMA_FILE;
+	if (finfo.type == VMA_SHMEM)
+		return;
 
 	/* Find owning device's queue/read_ahead_kb control */
 	if (snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/uevent",
_

Patches currently in -mm which might be from zokeefe@google.com are

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-thp-collapse-shmem-testing-fix.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