On 9/1/22 10:43 AM, Jens Axboe wrote: > On Thu, 25 Aug 2022 07:53:12 -0700, Keith Busch wrote: >> From: Keith Busch <kbusch@xxxxxxxxxx> >> >> Batched completions can clear multiple bits, but we're only decrementing >> the wait_cnt by one each time. This can cause waiters to never be woken, >> stalling IO. Use the batched count instead. >> >> >> [...] > > Applied, thanks! > > [1/1] sbitmap: fix batched wait_cnt accounting > commit: 16ede66973c84f890c03584f79158dd5b2d725f5 This is causing CPU stalls for me running make -j256 with the source hosted on an ATA device with QD=32. It's not running with a scheduler. It just goes spammy on most/all CPUs so hard to get a real trace out of it, but it looks like we're just looping forever off sbitmap_queue_wake_up(). I'm going to revert this one for now until we can investigate what is going on here. -- Jens Axboe
