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| author | Jens Axboe <jens.axboe@oracle.com> | 2006-12-20 11:06:15 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2006-12-20 11:06:15 +0100 |
| commit | 126ec9a676f601818dc3a85af0552b146410d888 (patch) | |
| tree | 5cf2bae7274acf4037159b55930fd91a78967b09 /Documentation/block | |
| parent | [PATCH] cfq-iosched: don't allow sync merges across queues (diff) | |
| download | linux-126ec9a676f601818dc3a85af0552b146410d888.tar.xz linux-126ec9a676f601818dc3a85af0552b146410d888.zip | |
[PATCH] block: document io scheduler allow_merge_fn hook
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'Documentation/block')
| -rw-r--r-- | Documentation/block/biodoc.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index c6c9a9c10d7f..3adaace328a6 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -946,6 +946,13 @@ elevator_merged_fn called when a request in the scheduler has been scheduler for example, to reposition the request if its sorting order has changed. +elevator_allow_merge_fn called whenever the block layer determines + that a bio can be merged into an existing + request safely. The io scheduler may still + want to stop a merge at this point if it + results in some sort of conflict internally, + this hook allows it to do that. + elevator_dispatch_fn fills the dispatch queue with ready requests. I/O schedulers are free to postpone requests by not filling the dispatch queue unless @force |