On Tue, Feb 20, 2018 at 12:37:07PM -1000, Jens Axboe wrote: > 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. Being ever more forgetful (I blame the kids) I find Changelogs more and more important, ymmv ;-) > > 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. Right missed that. In fact, possibly the only reason I saw this is that Nitesh had this computer configured wrong and the email is from the future and thus the very first entry in my lkml folder.
