Lines Matching refs:to

4 Try to keep transactionality out of it.  The core is careful to
6 makes it easier to write the policies.
10 Every bio that is mapped by the target is referred to the policy.
13 Currently there's no way for the policy to issue background work,
14 e.g. to start writing back dirty blocks that are going to be evicte
18 to get fooled by many small bios.  For this reason the core target
19 issues periodic ticks to the policy.  It's suggested that the policy
22 trying to see when the io scheduler has let the ios run.
39 on hit count on entry. The policy aims to take different cache miss
40 costs into account and to adjust to varying load patterns automatically.
55 The sequential and random thresholds default to 512 and 4 respectively.
58 since spindles tend to have good sequential I/O bandwidth.  The
59 io_tracker counts contiguous I/Os to try to spot when the I/O is in one
60 of these sequential modes.  But there are use-cases for wanting to
61 promote sequential blocks to the cache (e.g. fast application startup).
62 If sequential threshold is set to 0 the sequential I/O detection is
64 Setting the random threshold to 0 does _not_ disable the random I/O
69 promoted to the cache.  The read, write and discard promote adjustment
70 tunables allow you to tweak the promotion threshold by adding a small
71 value based on the io type.  They default to 4, 8 and 1 respectively.
72 If you're trying to quickly warm a new cache device you may wish to
73 reduce these to encourage promotion.  Remember to switch them back to
88 Users may switch from "mq" to "smq" simply by appropriately reloading a
90 mq policy's hints to be dropped.  Also, performance of the cache may
98 SMQ uses 28bit indexes to implement it's data structures rather than
122 different block to get promoted to the cache it's hit count has to
124 long time for the cache to adapt between varying IO patterns.
130 is used to decide which blocks to promote.  If the hotspot queue is
132 levels.  This lets it adapt to new IO patterns very quickly.
140 The cleaner writes back all dirty blocks in a cache to decommission it.
150 The syntax to send a message using the dmsetup command is:
158 	sequential threshold set to 1024 and the random_threshold set to 8.