On 2011-02-02 23:55, Mike Snitzer wrote:

Set REQ_SORTED, in the @rw_flags passed to the request allocator, for
any request that may be put on IO scheduler.  Skip elevator data
initialization during request allocation if REQ_SORTED is not set.

REQ_SORTED is not set for flush requests because they are never put on
the IO scheduler.

That looks very wrong. REQ_SORTED gets set _when_ the request is sorted
into the IO scheduler. This is gross misuse, a bad hack.

-- 
Jens Axboe