[Kittyhawk] Another trace

Jonathan Appavoo jappavoo at bu.edu
Sun Sep 18 21:46:10 EDT 2011


This seems to collaborate the scenario that Dan and I were discussing but
had not had time to verify yet.  If this trace and our theory check out we
should be able to verify with a simpler test case and also setup a quick fix
along with a longer term fix.  We will try and work on it tomorrow.

Jonathan.

On Sep 18, 2011, at 10:37 AM, Eric Van Hensbergen wrote:

> looks like maybe a deadlock if we print during a fault handler when
> someone else is holding onto tree->lock (?)
> Of course, the fourth core is timing out talking to one of the other
> cores because they aren't responding to an IPI, so maybe some sort of
> deadlock between bgcon->lock {5}.0 and tree->lock {5}.2
> 
>       -eric
> 
> 
> haredebug[ANL-R00-M0-N14-64]>{5} dumpier
> OK
> {5}.0 IAR:  0xc029c18c    LR:  0xc01de72c      (spin lock in
> con_flush)  (bgcon->lock)
> {5}.1 IAR:  0xc0007b74    LR:  0xc0007b88      (cpu idle)
> {5}.2 IAR:  0xc029c4c8    LR:  0xc01d8094      (spin lock_irqsave in
> bgtree_enable_inject_wm_interrupt) (tree->lock)
> {5}.3 IAR:  0xc029c4c8    LR:  0xc01d7a64      (spin lock in
> bgtree_xmit) (tree->lock)
> 
> haredebug[ANL-R00-M0-N14-64]>{5} dump_stacks
> OK
> {5}.0 Dump stack
> Core 0 Stack Dump
> 0xeff89c90  0xc01de7d0     con_flush
> 0xeff89cc0  0xc01d83f4     bgtree_inject_interrupt
> 0xeff89ce0  0xc00576e4    handle_IRQ_event
> 0xeff89d00  0xc0059754    handle_fasteoi_irq
> 0xeff89d20  0xc0004418    do_IRQ
> 0xeff89de0  0xc000fc04     ret_from_except
> 0xeff89e10  0xc01deae0    bg_tty_write
> 0xeff89e20  0xc019101c    tty_defaul_put_char
> 0xeff89e30  0xc0196778    opost
> 0xeff89f30  0xc0197908     n_tty_receive_buf
> 0xeff89f60  0xc0191d60     flush_to_ldisc
> 0xeff89f90  0xc0044bf0      run_workqueue
> 0xeff89fd0  0xc0045314     worker_thread
> 0xeff89ff0  0xc004a0d4      kthread
> 0x00000000  0xc0010658
> {5}.1 Dump stack
> Core 1 Stack Dump
> 0xeffc5fe0  0xc0007b88     cpu_idle
> 0xeffc5ff0  0xc00109bc
> 0x00000000  0xc0000258
> {5}.2 Dump stack
> Core 2 Stack Dump
> 0xc049de10  0xc01d7a88   bgtree_xmit
> 0xc049de20  0xc01de9ac   enqueue_retransmit calling
> bgtree_enable_inj_wm_interrupt
> 0xc049de50  0xc01deae0   bg_tty_write (calling enque retransmit)
> 0xc049deb0  0xc0198808  write_chan
> 0xc049def0  0xc0193808   tty_write
> 0xc049df10  0xc008c7e0   vfs_write
> 0xc049df40  0xc008c9b8   file_pos_write
> 0x7f8e6960  0xc000f5c4    ret_from_syscall
> Invalid value in Link register: Oldframe=0xc049df40  Newframe=0x7f8e6960
> {5}.3 Dump stack
> Core 3 Stack Dump
> 0xdfeebb80  0xc140692c
> 0xdfeebbd0  0xc01dde44     do_write
> 0xdfeebbf0  0xc01ddec0      bg_console_write
> 0xdfeebc10  0xc002d9ec     call_console drivers
> 0xdfeebc50  0xc002df08     release_console_Sem
> 0xdfeebce0  0xc002e7ec     vprintk
> 0xdfeebd20  0xc002e900     printk
> 0xdfeebd70  0xc0010cf0      smp_call_function_map (timing out response
> from other cpu)
> 0xdfeebda0  0xc0010e08     smp_flush_tlb_page
> 0xdfeebde0  0xc006d4c0     do_wp_page
> 0xdfeebe70  0xc006ffa8       __handle_mm_fault
> 0xdfeebf40  0xc00132a4      do_page_fault
> 0x7f8e6940  0xc000fa00      handle_page_fault
> Invalid value in Link register: Oldframe=0xdfeebf40  Newframe=0x7f8e6940
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