Messages in this thread | | | Date | Tue, 12 Jul 2011 08:15:13 -0400 | From | Vivek Goyal <> | Subject | Re: [PATCH v2 0/3]CFQ: add think time check for service tree and group |
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On Tue, Jul 12, 2011 at 09:37:52AM +0800, Shaohua Li wrote: > Hi, > Currently when the last queue of a service tree/group is empty, CFQ > doesn't expire the queue. This is to allow requests from the tree/group > come soon, so tree/group doesn't miss its share. But if the think time > is big, the assumption isn't correct. idling the queue is just wasting > bandwidth. > > Originally I was hoping this can resolve Vivek's fsync issue, but it > doesn't. The fsync issue is caused by queue idling. But since think time > check only helps for think time above default queue idle time (8ms), > think time check doesn't help for the fsync issue. > > On the other hand, think time check is still helpful for queues with > think time. I had test case in follow patches show throughput > improvement without sacrifice tree/group shares. > > v1->v2: > 1. addressed some good comments from Vivek > 2. add more test to make sure the patches don't change behavior of > queues without think time.
This patch series looks good to me. Thanks Shaohua. We still shall have to do something about fsync issue though in groups.
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Thanks Vivek
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