On Wed, Dec 06, 2023 at 05:30:10PM +0100, Mateusz Guzik wrote: > > What the hell is going on? Was ->d_lock on parent serving as a throttle and reducing > > the access rate to something badly contended down the road? I don't see anything > > of that sort in the profile changes, though... > Not an outlandish claim would be that after you stopped taking one of > them, spinning went down and more traffic was put on locks which *can* > put their consumers off cpu (and which *do* do it in this test). That's about the only guess I've got (see above), but if that's the case, which lock would that be? > All that said I think it would help if these reports started including > off cpu time (along with bt) at least for spawned threads.