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| author | Bart Van Assche <bvanassche@acm.org> | 2019-08-02 00:50:44 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-08-05 05:41:29 +0200 |
| commit | 9cc5169cd478bc596902a57580804f1da3dfd74e (patch) | |
| tree | 98fedd293733a36dae88142eafd518688ada4fbd /crypto/crypto_user_stat.c | |
| parent | block: Simplify blk_bio_segment_split() (diff) | |
| download | linux-9cc5169cd478bc596902a57580804f1da3dfd74e.tar.xz linux-9cc5169cd478bc596902a57580804f1da3dfd74e.zip | |
block: Improve physical block alignment of split bios
Consider the following example:
* The logical block size is 4 KB.
* The physical block size is 8 KB.
* max_sectors equals (16 KB >> 9) sectors.
* A non-aligned 4 KB and an aligned 64 KB bio are merged into a single
non-aligned 68 KB bio.
The current behavior is to split such a bio into (16 KB + 16 KB + 16 KB
+ 16 KB + 4 KB). The start of none of these five bio's is aligned to a
physical block boundary.
This patch ensures that such a bio is split into four aligned and
one non-aligned bio instead of being split into five non-aligned bios.
This improves performance because most block devices can handle aligned
requests faster than non-aligned requests.
Since the physical block size is larger than or equal to the logical
block size, this patch preserves the guarantee that the returned
value is a multiple of the logical block size.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'crypto/crypto_user_stat.c')
0 files changed, 0 insertions, 0 deletions