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| author | Stefan Haberland <sth@linux.vnet.ibm.com> | 2016-02-12 14:50:52 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-03 15:07:12 -0800 |
| commit | a90ad5c546fa28f28f5870d884603a7822e9c82a (patch) | |
| tree | 235e07a83d21f5c7caeada299c4d46b9845ab170 /drivers/s390 | |
| parent | 2e80d52bc8fb39da0208d73bb2a2ef7f10b7db2e (diff) | |
s390/dasd: fix performance drop
commit 12d319b920fa673a4d5e7c1785c5dc82dcd15257 upstream.
Commit ca369d51b ("sd: Fix device-imposed transfer length limits")
introduced a new queue limit max_dev_sectors which limits the maximum
sectors for requests. The default value leads to small dasd requests
and therefor to a performance drop.
Set the max_dev_sectors value to the same value as the max_hw_sectors
to use the maximum available request size for DASD devices.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/block/dasd.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index a263c10359e1..4abfbdb285ec 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -3031,6 +3031,7 @@ static void dasd_setup_queue(struct dasd_block *block) max = block->base->discipline->max_blocks << block->s2b_shift; } queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue); + block->request_queue->limits.max_dev_sectors = max; blk_queue_logical_block_size(block->request_queue, block->bp_block); blk_queue_max_hw_sectors(block->request_queue, max); |