Ingo Molnar wrote: > * Kamalesh Babulal <[EMAIL PROTECTED]> wrote: > >> While booting with the 2.6.25-rc1-git1 kernel on the powerbox the >> softlockup is seen, with following trace. > >> BUG: soft lockup - CPU#1 stuck for 61s! [insmod:377] >> TASK = c00000077cb2f0e0[377] 'insmod' THREAD: c00000077cb28000 CPU: 1 >> NIP [c0000000001b172c] .radix_tree_gang_lookup+0xdc/0x1e4 >> LR [c0000000001a6f00] .call_for_each_cic+0x50/0x10c >> Call Trace: >> [c00000077cb2bb20] [c0000000001a6f60] .call_for_each_cic+0xb0/0x10c >> (unreliable) >> [c00000077cb2bc60] [c00000000019ecd8] .exit_io_context+0xf0/0x110 >> [c00000077cb2bcf0] [c00000000006254c] .do_exit+0x820/0x850 >> [c00000077cb2bda0] [c000000000062648] .do_group_exit+0xcc/0xe8 >> [c00000077cb2be30] [c00000000000872c] syscall_exit+0x0/0x40 > > this call_for_each_cic/radix_tree_gang_lookup locked up, and all other > CPUs deadlocked in stopmachine, due to this one. > > call_for_each_cic is in ./block/cfq-iosched.c uses RCU, but you've got > classic-RCU: > > CONFIG_CLASSIC_RCU=y > # CONFIG_PREEMPT_RCU is not set > > so it's not related to the preempt-RCU changes either. > > It is this part that locks up: > > do { > ... > nr = radix_tree_gang_lookup(&ioc->radix_root, (void **) cics, > index, CIC_GANG_NR); > ... > } while (nr == CIC_GANG_NR); > ... > > it seems the radix tree will yield new entries again and again. Either > it got corrupted, or some other CPU is filling it faster than we can > deplete it [unlikely i think]. > > Ingo
This softlockup is seen with the 2.6.25-rc1-git3 also. Let me know if you need more details. -- Thanks & Regards, Kamalesh Babulal, Linux Technology Center, IBM, ISTL. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev