create_pagecache_thp_and_fd() was previously writing a file sized at twice
the PMD size by making a per-byte write syscall. This was quite slow when
the PMD size is 4M, but completely intolerable for 32M (PMD size for
arm64's 16K page size), and 512M (PMD size for arm64's 64K page size).
The byte pattern has a 256 byte period, so let's create a 1K buffer and
fill it with exactly 4 periods. Then we can write the buffer as many
times as is required to fill the file. This makes things much more
tolerable.
The test now passes for 16K page size. It still fails for 64K page size
because MAX_PAGECACHE_ORDER is too small for 512M folio size (I think).
Link: https://lkml.kernel.org/r/20250318174343.243631-3-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Rafael Aquini <raquini@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
create_pagecache_thp_and_fd() in split_huge_page_test.c used the variable
dummy to perform mmap read.
However, this test was skipped even on XFS which has large folio support.
The issue was compiler (gcc 13.2.0) was optimizing out the dummy variable,
therefore, not creating huge page in the page cache.
Use asm volatile() trick to force the compiler not to optimize out the
loop where we read from the mmaped addr. This is similar to what is being
done in other tests (cow.c, etc)
As the variable is now used in the asm statement, remove the unused
attribute.
Link: https://lkml.kernel.org/r/20240606203619.677276-1-kernel@pankajraghav.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix the warnings by initializing and marking the variable as unused.
I've caught the warnings by using clang.
split_huge_page_test.c:303:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
303 | int dummy;
| ^
split_huge_page_test.c:343:3: warning: variable 'dummy' is uninitialized when used here [-Wuninitialized]
343 | dummy += *(*addr + i);
| ^~~~~
split_huge_page_test.c:303:11: note: initialize the variable 'dummy' to silence this warning
303 | int dummy;
| ^
| = 0
2 warnings generated.
Link: https://lkml.kernel.org/r/20240416162658.3353622-1-usama.anjum@collabora.com
Fixes: fc4d182316 ("mm: huge_memory: enable debugfs to split huge pages to any order")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add missing flags argument to open(2) call with O_CREAT.
Some tests fail to compile if _FORTIFY_SOURCE is defined (to any valid
value) (together with -O), resulting in similar error messages such as:
In file included from /usr/include/fcntl.h:342,
from gup_test.c:1:
In function 'open',
inlined from 'main' at gup_test.c:206:10:
/usr/include/bits/fcntl2.h:50:11: error: call to '__open_missing_mode' declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
50 | __open_missing_mode ();
| ^~~~~~~~~~~~~~~~~~~~~~
_FORTIFY_SOURCE is enabled by default in some distributions, so the
tests are not built by default and are skipped.
open(2) man-page warns about missing flags argument: "if it is not
supplied, some arbitrary bytes from the stack will be applied as the
file mode."
Link: https://lkml.kernel.org/r/20240318023445.3192922-1-vt@altlinux.org
Fixes: aeb85ed4f4 ("tools/testing/selftests/vm/gup_benchmark.c: allow user specified file")
Fixes: fbe37501b2 ("mm: huge_memory: debugfs for file-backed THP split")
Fixes: c942f5bd17 ("selftests: soft-dirty: add test for mprotect")
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: (pte|pmd)_mkdirty() should not unconditionally allow for
write access".
This is the follow-up on [1], adding selftests (testing for known issues
we added workarounds for and other issues that haven't been fixed yet),
fixing sparc64, reverting the workarounds, and perform one cleanup.
The patch from [1] was modified slightly (updated/extended patch
description, dropped one unnecessary NOP instruction from the ASM in
__pte_mkhwwrite()).
Retested on x86_64 and sparc64 (sun4u in QEMU).
I scanned most architectures to make sure their (pte|pmd)_mkdirty()
handling is correct. To be sure, we can run the selftests and find out if
other architectures are still affectes (loongarch was fixed recently as
well).
Based on master for now. I don't expect surprises regarding mm-tress, but
I can rebase if there are any problems.
This patch (of 6):
The COW selftest can deal with THP not being configured. So move error
handling of read_pmd_pagesize() into the callers such that we can reuse it
in the COW selftest.
Link: https://lkml.kernel.org/r/20230411142512.438404-1-david@redhat.com
Link: https://lkml.kernel.org/r/20221212130213.136267-1-david@redhat.com [1]
Link: https://lkml.kernel.org/r/20230411142512.438404-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
