From 7f52f98c2a83339b89a27d01296354e5dbb90ad0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 14 May 2013 13:52:37 -0700 Subject: [PATCH] blk-throttle: implement dispatch looping throtl_select_dispatch() only dispatches throtl_quantum bios on each invocation. blk_throtl_dispatch_work_fn() in turn depends on throtl_schedule_next_dispatch() scheduling the next dispatch window immediately so that undue delays aren't incurred. This effectively chains multiple dispatch work item executions back-to-back when there are more than throtl_quantum bios to dispatch on a given tick. There is no reason to finish the current work item just to repeat it immediately. This patch makes throtl_schedule_next_dispatch() return %false without doing anything if the current dispatch window is still open and updates blk_throtl_dispatch_work_fn() repeat dispatching after cpu_relax() on %false return. This change will help implementing hierarchy support as dispatching will be done from pending_timer and immediate reschedule of timer function isn't supported and doesn't make much sense. While this patch changes how dispatch behaves when there are more than throtl_quantum bios to dispatch on a single tick, the behavior change is immaterial. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal --- Reading git-format-patch failed