[PATCH 05/19] s390/dasd: Optimize max blocks per request for track alignment
Stefan Haberland <[email protected]>
| Newsgroups | org.kernel.vger.linux-s390,org.kernel.vger.linux-block |
|---|---|
| Message-ID | <[email protected]> |
With 4096-byte blocks a full ECKD track holds exactly 12 records. Lower DASD_ECKD_MAX_BLOCKS from 190 to 180 so requests align to track boundaries (15 full tracks); full-track I/O is more efficient than partial-track writes, and 190 had no alignment significance and could let a request cross a track boundary. Reviewed-by: Jan Höppner <[email protected]> Signed-off-by: Stefan Haberland <[email protected]> --- drivers/s390/block/dasd_eckd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h index f9299bd184ba..763733bcc4d2 100644 --- a/drivers/s390/block/dasd_eckd.h +++ b/drivers/s390/block/dasd_eckd.h @@ -131,7 +131,7 @@ /* * Maximum number of blocks to be chained */ -#define DASD_ECKD_MAX_BLOCKS 190 +#define DASD_ECKD_MAX_BLOCKS 180 #define DASD_ECKD_MAX_BLOCKS_RAW 256 /***************************************************************************** -- 2.53.0