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17 May 2024, 09:02:56 UTC
Revision 3440c49f5c5ecb4f29b0544aa87da71888404f8f authored by Divyesh Shah on 09 April 2010, 07:29:57 UTC, committed by Jens Axboe on 09 April 2010, 07:29:57 UTC 
cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
 
When CFQ dispatches requests forcefully due to a barrier or changing iosched,
it runs through all cfqq's dispatching requests and then expires each queue.
However, it does not activate a cfqq before flushing its IOs resulting in
using stale values for computing slice_used.
This patch fixes it by calling activate queue before flushing reuqests from
each queue.

This is useful mostly for barrier requests because when the iosched is changing
it really doesnt matter if we have incorrect accounting since we're going to
break down all structures anyway.

We also now expire the current timeslice before moving on with the dispatch
to accurately account slice used for that cfqq.

Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
1 parent 02246c4
History
Tip revision: 3440c49f5c5ecb4f29b0544aa87da71888404f8f authored by Divyesh Shah on 09 April 2010, 07:29:57 UTC
cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
Tip revision: 3440c49
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