On 02/25/2011 02:18 PM, Tejun Heo wrote: > Hello, > > On Fri, Feb 25, 2011 at 12:46:16PM +0100, Dominik Klein wrote: >> With 2.6.37 (also tried .1 and .2) it does not work but end up like I >> documented. With 2.6.38-rc1, it does work. With deadline scheduler, it >> also works in 2.6.37. > > Okay, here's the problematic part. > > <idle>-0 [013] 1640.975562: workqueue_queue_work: work struct=ffff88080f14f270 function=blk_throtl_work workqueue=ffff88102c8fc700 req_cpu=13 cpu=13 > <idle>-0 [013] 1640.975564: workqueue_activate_work: work struct ffff88080f14f270 > <...>-477 [013] 1640.975574: workqueue_execute_start: work struct ffff88080f14f270: function blk_throtl_work > <idle>-0 [013] 1641.087450: workqueue_queue_work: work struct=ffff88080f14f270 function=blk_throtl_work workqueue=ffff88102c8fc700 req_cpu=13 cpu=13 > > The workqueue is per-cpu, so we only need to follow cpu=13 cases. > @1640, blk_throtl_work() is queued, activated and starts executing but > never finishes. The same work item is never executed more than once > at the same on the same CPU, so when the next work item is queued, it > doesn't get activated until the previous execution is complete. > > The next thing to do would be finding out why blk_throtl_work() isn't > finishing. sysrq-t or /proc/PID/stack should show us where it's > stalled. > > Thanks. > See attached logs of another run. sysctl -w kernel.sysrq=1 echo blk > /sys/kernel/debug/tracing/current_tracer echo 1 > /sys/block/sdb/trace/enable echo workqueue_queue_work >> /sys/kernel/debug/tracing/set_event echo workqueue_activate_work >> /sys/kernel/debug/tracing/set_event echo workqueue_execute_start >> /sys/kernel/debug/tracing/set_event echo workqueue_execute_end >> /sys/kernel/debug/tracing/set_event That makes attachment trace_pipe5.gz echo 8 > /proc/sysrq-trigger echo t > /proc/sysrq-trigger That makes attachment console.gz hth Dominik
Attachment:
console.gz
Description: application/gzip
Attachment:
trace_pipe5.gz
Description: application/gzip
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list