linux/block
Tejun Heo e71357e118 cfq-iosched: add leaf_weight
cfq blkcg is about to grow proper hierarchy handling, where a child
blkg's weight would nest inside the parent's.  This makes tasks in a
blkg to compete against both tasks in the sibling blkgs and the tasks
of child blkgs.

We're gonna use the existing weight as the group weight which decides
the blkg's weight against its siblings.  This patch introduces a new
weight - leaf_weight - which decides the weight of a blkg against the
child blkgs.

It's named leaf_weight because another way to look at it is that each
internal blkg nodes have a hidden child leaf node which contains all
its tasks and leaf_weight is the weight of the leaf node and handled
the same as the weight of the child blkgs.

This patch only adds leaf_weight fields and exposes it to userland.
The new weight isn't actually used anywhere yet.  Note that
cfq-iosched currently offcially supports only single level hierarchy
and root blkgs compete with the first level blkgs - ie. root weight is
basically being used as leaf_weight.  For root blkgs, the two weights
are kept in sync for backward compatibility.

v2: cfqd->root_group->leaf_weight initialization was missing from
    cfq_init_queue() causing divide by zero when
    !CONFIG_CFQ_GROUP_SCHED.  Fix it.  Reported by Fengguang.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
2013-01-09 08:05:10 -08:00
..
partitions Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block 2012-12-17 13:39:11 -08:00
blk-cgroup.c cfq-iosched: add leaf_weight 2013-01-09 08:05:10 -08:00
blk-cgroup.h cfq-iosched: add leaf_weight 2013-01-09 08:05:10 -08:00
blk-core.c block: export block_unplug tracepoint 2012-12-14 20:49:27 +01:00
blk-exec.c Merge branch 'for-3.8/core' of git://git.kernel.dk/linux-block 2012-12-17 08:27:23 -08:00
blk-flush.c blk-flush: move the queue kick into 2011-10-24 16:24:31 +02:00
blk-integrity.c block: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros 2011-10-31 19:31:12 -04:00
blk-ioc.c block: uninitialized ioc->nr_tasks triggers WARN_ON 2012-08-01 12:17:27 +02:00
blk-iopoll.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
blk-lib.c block: add plug for blkdev_issue_discard 2012-12-14 20:46:04 +01:00
blk-map.c block: re-use existing 'reading' variable instead of checking direction again 2011-12-21 15:27:24 +01:00
blk-merge.c block: Implement support for WRITE SAME 2012-09-20 14:31:45 +02:00
blk-settings.c block: discard granularity might not be power of 2 2012-12-14 20:46:04 +01:00
blk-softirq.c sched, block: Unify cache detection 2012-01-27 13:28:48 +01:00
blk-sysfs.c block: Rename queue dead flag 2012-12-06 14:30:58 +01:00
blk-tag.c block/blk-tag.c: Remove useless kfree 2012-09-12 22:25:12 +02:00
blk-throttle.c block: Rename queue dead flag 2012-12-06 14:30:58 +01:00
blk-timeout.c block: Drop dead function blk_abort_queue() 2012-06-15 08:46:23 +02:00
blk.h block: Avoid that request_fn is invoked on a dead queue 2012-12-06 14:32:01 +01:00
bsg-lib.c bsg: Remove unused function bsg_goose_queue() 2012-12-06 14:33:02 +01:00
bsg.c bsg: fix sysfs link remove warning 2012-02-08 20:02:03 +01:00
cfq-iosched.c cfq-iosched: add leaf_weight 2013-01-09 08:05:10 -08:00
compat_ioctl.c block: Add BLKROTATIONAL ioctl 2012-01-11 16:29:31 +01:00
deadline-iosched.c deadline: Allow 0ms deadline latency, increase the read speed 2012-12-09 19:19:23 +01:00
elevator.c block: recursive merge requests 2012-11-09 08:44:27 +01:00
genhd.c Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block 2012-12-17 13:39:11 -08:00
ioctl.c Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-block 2012-10-11 09:04:23 +09:00
Kconfig percpu_rw_semaphore: introduce CONFIG_PERCPU_RWSEM 2012-12-17 17:15:18 -08:00
Kconfig.iosched blkcg: make CONFIG_BLK_CGROUP bool 2012-03-06 21:27:21 +01:00
Makefile separate partition format handling from generic code 2012-01-03 22:54:06 -05:00
noop-iosched.c elevator: make elevator_init_fn() return 0/-errno 2012-03-06 21:27:21 +01:00
partition-generic.c block: add partition resize function to blkpg ioctl 2012-08-01 12:24:18 +02:00
scsi_ioctl.c scsi: Silence unnecessary warnings about ioctl to partition 2012-06-15 12:52:46 +02:00