From: Andrew Morton <akpm@linux-foundation.org>
To: wang lian <lianux.mm@gmail.com>
Cc: broonie@kernel.org, david@redhat.com, lorenzo.stoakes@oracle.com,
sj@kernel.org, ziy@nvidia.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, brauner@kernel.org,
jannh@google.com, Liam.Howlett@oracle.com, shuah@kernel.org,
vbabka@suse.cz, ludovico.zy.wu@gmail.com, gkwang@linx-info.com,
p1ucky0923@gmail.com, ryncsn@gmail.com, zijing.zhang@proton.me
Subject: Re: [PATCH] selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));"
Date: Wed, 16 Jul 2025 15:15:43 -0700 [thread overview]
Message-ID: <20250716151543.998b121a58064011e9ce68cb@linux-foundation.org> (raw)
In-Reply-To: <20250716123126.3851-1-lianux.mm@gmail.com>
On Wed, 16 Jul 2025 20:31:26 +0800 wang lian <lianux.mm@gmail.com> wrote:
> Several mm selftests use the `asm volatile("" : "+r" (variable));`
> construct to force a read of a variable, preventing the compiler from
> optimizing away the memory access. This idiom is cryptic and duplicated
> across multiple test files.
>
> Following a suggestion from David[1], this patch refactors this
> common pattern into a FORCE_READ() macro
>
> tools/testing/selftests/mm/cow.c | 30 +++++++++----------
> tools/testing/selftests/mm/hugetlb-madvise.c | 5 +---
> tools/testing/selftests/mm/migration.c | 13 ++++----
> tools/testing/selftests/mm/pagemap_ioctl.c | 4 +--
> .../selftests/mm/split_huge_page_test.c | 4 +--
> 5 files changed, 24 insertions(+), 32 deletions(-)
The patch forgot to move the FORCE_READ definition into a header?
next prev parent reply other threads:[~2025-07-16 22:15 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-16 12:31 wang lian
2025-07-16 13:16 ` David Hildenbrand
2025-07-16 22:15 ` Andrew Morton [this message]
2025-07-17 6:58 ` Wei Yang
2025-07-17 10:48 ` wang lian
2025-07-17 11:43 ` David Hildenbrand
2025-07-19 9:27 ` David Laight
2025-07-20 9:23 ` Lorenzo Stoakes
2025-07-20 11:03 ` wang lian
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