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| author | Ming Lei <ming.lei@redhat.com> | 2024-02-25 11:01:41 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-06 14:45:19 +0000 |
| commit | 0e351d1aa2e4c1a7a4cb2a5753b86db89796d3c8 (patch) | |
| tree | 44e1b4c4716f5dfcff57a5f2ce9ec7d96fe576b7 | |
| parent | c6ff5fb6b157cf4101889c1f3e169eb6897e8f50 (diff) | |
| download | linux-0e351d1aa2e4c1a7a4cb2a5753b86db89796d3c8.tar.gz | |
block: define bvec_iter as __packed __aligned(4)
[ Upstream commit 7838b4656110d950afdd92a081cc0f33e23e0ea8 ]
In commit 19416123ab3e ("block: define 'struct bvec_iter' as packed"),
what we need is to save the 4byte padding, and avoid `bio` to spread on
one extra cache line.
It is enough to define it as '__packed __aligned(4)', as '__packed'
alone means byte aligned, and can cause compiler to generate horrible
code on architectures that don't support unaligned access in case that
bvec_iter is embedded in other structures.
Cc: Mikulas Patocka <mpatocka@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 19416123ab3e ("block: define 'struct bvec_iter' as packed")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/linux/bvec.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/bvec.h b/include/linux/bvec.h index 9e3dac51eb26b6..d4dbaae8b5218a 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -59,7 +59,7 @@ struct bvec_iter { unsigned int bi_bvec_done; /* number of bytes completed in current bvec */ -} __packed; +} __packed __aligned(4); struct bvec_iter_all { struct bio_vec bv; |