Messages in this thread |  | | Date | Thu, 23 Apr 2009 15:53:51 +0800 | | From | Gui Jianfeng <> | | Subject | Re: [PATCH 5/7] kiothrottled: throttle buffered (writeback) IO |
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Andrea Righi wrote: > Together with cgroup_io_throttle() the kiothrottled kernel thread > represents the core of the io-throttle subsystem. > > All the writeback IO requests that need to be throttled are not > dispatched immediately in submit_bio(). Instead, they are added into an > rbtree by iothrottle_make_request() and processed asynchronously by > kiothrottled. > > A deadline is associated to each request depending on the bandwidth > usage of the cgroup it belongs. When a request is inserted into the > rbtree kiothrottled is awakened. This thread selects all the requests > with an expired deadline and submit the bunch of selected requests to > the underlying block devices using generic_make_request().
Hi Andrea,
What if an user issues "sync", will the bios still be buffered in the rb-tree? Do we need to flush the whole tree?
-- Regards Gui Jianfeng
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