Hi, On Fri, 15 Jan 2010 16:02:02 -0800, Nagaprabhanjan Bellari <nagp.knb@xxxxxxxxx> wrote: > Hi, > > We had a problem where we were trying to debug why events/0 was taking 98% > of CPU time. I found that writing a ‘t’ to /proc/sysrq-trigger will > dump the > stack traces of all processes. Unfortunately, events/0 was shown as running > and no stack trace was dumped for it: > > == > ksoftirqd/0 S 00000000 0 2 1 3 (L-TLB) > Call trace: > 5fe8bf50 [4000556c] __switch_to+0x60/0x9c > 5fe8bf60 [4026a37c] schedule+0x314/0x75c > 5fe8bfa0 [40026e3c] ksoftirqd+0xb0/0xb4 > 5fe8bfc0 [4003847c] kthread+0xec/0x128 > 5fe8bff0 [40005370] kernel_thread+0x44/0x60 > Next sp 0! > > events/0 R running 0 3 1 4 2 > (L-TLB) <===== no stack trace for this. :-( > > khelper S 00000000 0 4 1 5 3 (L-TLB) > Call trace: > 5ff47ef0 [4000556c] __switch_to+0x60/0x9c > 5ff47f00 [4026a37c] schedule+0x314/0x75c > 5ff47f40 [400333e4] worker_thread+0x214/0x218 > 5ff47fc0 [4003847c] kthread+0xec/0x128 > 5ff47ff0 [40005370] kernel_thread+0x44/0x60 > Next sp 0! > == > > > Can one of you tell me how to get the stack trace of a running process? Or > any other ideas/suggestions to see what events/0 is up to? > > Thanks, > -nagp It does sound strange. I'll venture a guess, perhaps it's waiting for an event, so there's no stack to trace ? You could tell in /proc, but it's probably waiting for a workerthread, You can tell in the waiting channel leaf node. HTH B rgds Kris -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
