From: Aaron Carroll Date: Tue, 30 Oct 2007 09:40:13 +0000 (+0100) Subject: Deadline iosched: Reset batch for ordered requests X-Git-Tag: v2.6.24-rc2~43^2~3 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dfb3d72a9aa519672c9ae06f0d2f93eccb35482f;p=linux-2.6 Deadline iosched: Reset batch for ordered requests The deadline I/O scheduler does not reset the batch count when starting a new batch at a higher-sectored request. This means the second and subsequent batch in the same data direction will never exceed a single request in size whenever higher-sectored requests are pending. This patch gives new batches in the same data direction as old ones their full quota of requests by resetting the batch count. Signed-off-by: Aaron Carroll Signed-off-by: Jens Axboe --- diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index a44437e5a9..cb94c83808 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -306,12 +306,11 @@ dispatch_writes: dispatch_find_request: /* * we are not running a batch, find best request for selected data_dir + * and start a new batch */ if (deadline_check_fifo(dd, data_dir)) { /* An expired request exists - satisfy it */ - dd->batching = 0; rq = rq_entry_fifo(dd->fifo_list[data_dir].next); - } else if (dd->next_rq[data_dir]) { /* * The last req was the same dir and we have a next request in @@ -325,12 +324,13 @@ dispatch_find_request: * higher-sectored requests. Go back to the lowest sectored * request (1 way elevator) and start a new batch. */ - dd->batching = 0; node = rb_first(&dd->sort_list[data_dir]); if (node) rq = rb_entry_rq(node); } + dd->batching = 0; + dispatch_request: /* * rq is the selected appropriate request.