From: Jens Axboe Date: Wed, 20 Dec 2006 10:06:15 +0000 (+0100) Subject: [PATCH] block: document io scheduler allow_merge_fn hook X-Git-Tag: v2.6.20-rc2~79^2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=126ec9a676f601818dc3a85af0552b146410d888;p=linux-2.6-omap-h63xx.git [PATCH] block: document io scheduler allow_merge_fn hook Signed-off-by: Jens Axboe --- diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index c6c9a9c10d7..3adaace328a 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