Re: [Qemu-devel] qemu_rearm_alarm_timer: do not call rearm if the next deadline is INT64_MAX

[Stefano Stabellini]

On Tue, 12 Jun 2012, Andreas Färber wrote:
> Am 12.06.2012 10:24, schrieb Andreas Färber:
> > Am 29.05.2012 15:35, schrieb Stefano Stabellini:
> > The check-qtest-i386 qemu-system-i386 process now hangs at ~98% CPU,

Does this mean that increasing the timeout caused a busy loop somewhere
in the test? But if we set the max timeout value to INT32_MAX doesn't
happen?


> > just as with my INT64_MAX hack before. How would I best debug this qtest
> > scenario, and what should I be looking for? Since my 1.1 patch this is
> > no longer going through any Cocoa event handling, so the only causes I
> > can think of are timers and signals...
> 
> Might this shed any light?
> 
> Analysis of sampling qemu-system-i386 (pid 19531) every 1 millisecond

So I take that the call graph below repeats itself every 1m?


> Call graph:
>     2337 Thread_2503
>       2337 0xffc
>         2337 start
>           2337 main
>             2337 qemu_main
>               2337 main_loop_wait
>                 2337 qemu_iohandler_poll
>                   2337 tcp_chr_read
>                     2337 qtest_read
>                       2337 memory_region_iorange_write
>                         2337 rtc_change_mon_event
>                           2337 monitor_protocol_event
>                             2337 monitor_json_emitter
>                               2337 monitor_puts
>                                 2337 monitor_flush
>                                   2177 write
>                                     2177 write
>                                   92 send_all
>                                     81 cerror
>                                       57 malloc_zone_malloc
>                                         35 __error
>                                           35 __error
>                                         17 dyld_stub___error
>                                           17 dyld_stub___error
>                                         5 cthread_set_errno_self
>                                           5 cthread_set_errno_self
>                                       24 cerror
>                                     11 send_all
>                                   36 dyld_stub_write
>                                     36 dyld_stub_write
>                                   24 dyld_stub___error
>                                     24 dyld_stub___error
>                                   6 cerror
>                                     6 cerror
>                                   2 __error
>                                     2 __error

What is the cause of these errors?


>     2337 Thread_2603
>       2337 _pthread_start
>         2337 sigwait_compat
>           2337 sigwait
>             2337 __sigwait
>               2337 __sigwait
>     2337 Thread_2703
>       2337 _pthread_start
>         2337 qemu_dummy_cpu_thread_fn
>           2337 sigwait
>             2337 __sigwait
>               2337 __sigwait
> 
> rtc-test is still blocked by the system() call apparently, and gtester
> is polling in its main loop.

Which system call?