On 2/20/18 3:21 AM, Peter Zijlstra wrote: > On Sun, May 30, 2083 at 09:51:06AM +0530, Nitesh Shetty wrote: >> This removes the dependency on interrupts to wake up task. Set task >> state as TASK_RUNNING, if need_resched() returns true, >> while polling for IO completion. >> Earlier, polling task used to sleep, relying on interrupt to wake it up. >> This made some IO take very long when interrupt-coalescing is enabled in >> NVMe. > > This is a horrible Changelog.. it does not in fact explain why the patch > works or is correct.
Yeah, that should have been improved. > Also, set_current_state(TASK_RUNNING) is dodgy (similarly in > __blk_mq_poll), why do you need that memory barrier? I pointed that out in the review, and v2 fixed it. v2 is the one that got merged. -- Jens Axboe
