From 34b48db66e08ca1c1bc07cf305d672ac940268dc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 6 Sep 2014 16:08:05 -0700 Subject: [PATCH] block: remove artifical max_hw_sectors cap Set max_sectors to the value the drivers provides as hardware limit by default. Linux had proper I/O throttling for a long time and doesn't rely on a artifically small maximum I/O size anymore. By not limiting the I/O size by default we remove an annoying tuning step required for most Linux installation. Note that both the user, and if absolutely required the driver can still impose a limit for FS requests below max_hw_sectors_kb. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-settings.c | 4 +--- drivers/block/aoe/aoeblk.c | 2 +- include/linux/blkdev.h | 1 - 3 files changed, 2 insertions(+), 5 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index aa02247..6ed2cbe 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -257,9 +257,7 @@ void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_ __func__, max_hw_sectors); } - limits->max_hw_sectors = max_hw_sectors; - limits->max_sectors = min_t(unsigned int, max_hw_sectors, - BLK_DEF_MAX_SECTORS); + limits->max_sectors = limits->max_hw_sectors = max_hw_sectors; } EXPORT_SYMBOL(blk_limits_max_hw_sectors); diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index dd73e1f..46c282f 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -395,7 +395,7 @@ aoeblk_gdalloc(void *vp) WARN_ON(d->flags & DEVFL_TKILL); WARN_ON(d->gd); WARN_ON(d->flags & DEVFL_UP); - blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS); + blk_queue_max_hw_sectors(q, 1024); q->backing_dev_info.name = "aoe"; q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE; d->bufpool = mp; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0207a78..74d14db 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1186,7 +1186,6 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, - BLK_DEF_MAX_SECTORS = 1024, BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, }; -- 2.7.4