• Tejun Heo's avatar
    block: strip out locking optimization in put_io_context() · 11a3122f
    Tejun Heo authored
    put_io_context() performed a complex trylock dancing to avoid
    deferring ioc release to workqueue.  It was also broken on UP because
    trylock was always assumed to succeed which resulted in unbalanced
    preemption count.
    While there are ways to fix the UP breakage, even the most
    pathological microbench (forced ioc allocation and tight fork/exit
    loop) fails to show any appreciable performance benefit of the
    optimization.  Strip it out.  If there turns out to be workloads which
    are affected by this change, simpler optimization from the discussion
    thread can be applied later.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    LKML-Reference: <1328514611.21268.66.camel@sli10-conroe>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>