|author||Linus Torvalds <email@example.com>||2012-04-13 18:07:19 -0700|
|committer||Linus Torvalds <firstname.lastname@example.org>||2012-04-13 18:07:19 -0700|
Merge branch 'for-3.4/core' of git://git.kernel.dk/linux-block
Pull block core bits from Jens Axboe: "It's a nice and quiet round this time, since most of the tricky stuff has been pushed to 3.5 to give it more time to mature. After a few hectic block IO core changes for 3.3 and 3.2, I'm quite happy with a slow round. Really minor stuff in here, the only real functional change is making the auto-unplug threshold a per-queue entity. The threshold is set so that it's low enough that we don't hold off IO for too long, but still big enough to get a nice benefit from the batched insert (and hence queue lock cost reduction). For raid configurations, this currently breaks down." * 'for-3.4/core' of git://git.kernel.dk/linux-block: block: make auto block plug flush threshold per-disk based Documentation: Add sysfs ABI change for cfq's target latency. block: Make cfq_target_latency tunable through sysfs. block: use lockdep_assert_held for queue locking block: blk_alloc_queue_node(): use caller's GFP flags instead of GFP_KERNEL
Diffstat (limited to 'Documentation')
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-cfq-target-latency b/Documentation/ABI/testing/sysfs-cfq-target-latency
new file mode 100644
@@ -0,0 +1,8 @@
+Date: March 2012
+contact: Tao Ma <email@example.com>
+ The /sys/block/<device>/iosched/target_latency only exists
+ when the user sets cfq to /sys/block/<device>/scheduler.
+ It contains an estimated latency time for the cfq. cfq will
+ use it to calculate the time slice used for every task.