Messages in this thread | | | Date | Wed, 30 Mar 2011 09:46:58 -0400 | From | Vivek Goyal <> | Subject | Re: [PATCH] block: eliminate ELEVATOR_INSERT_REQUEUE |
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On Wed, Mar 30, 2011 at 10:02:03AM +0200, Tejun Heo wrote: > Hello, Jens. > > On Wed, Mar 30, 2011 at 09:59:09AM +0200, Jens Axboe wrote: > > Pure front insert should be used for requeue and internal commands (like > > spin up this drive, or get error information). Flush should append to > > the dispatch list. > > Yeah, right. The reason I used REQUEUE/FRONT was because BACK > insertion involves draining the elevator and then appending the > request at the end of the dispatch queue, which is unnecessary and > inefficient. So, front insertion was a quick work around that. If > we're removing elv_insert(), we can just append directly to the > dispatch queue from flush code.
Hi Tejun,
With ordering semantics gone, do we still need to drain the elevator before queuing flush at the end of request queue.
Thanks Vivek
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