Re: [Valgrind-users] Valgrind on MIPS no output and 100% CPU

[Adam P. <ada...@ho...>]

Thanks for the suggestions. I'll try them and see how far I get.
Adam

> Subject: Re: [Valgrind-users] Valgrind on MIPS no output and 100% CPU
> From: phi...@sk...
> To: ada...@ho...
> CC: val...@li...
> Date: Wed, 14 Oct 2015 23:42:02 +0200
> 
> On Wed, 2015-10-14 at 15:30 +0100, Adam Porteous wrote
> 
> 
> >      1. I don't see any output on the console at all and can see that
> >         valgrind is nearly 100% CPU with the output from using top
> >         (hardware has 2 cores which explains the 48%):
> > 6210  6190 root     R    16004  13%   0  48%
> > {memcheck-mips32} ./valgrind
> 
> > I know this is not much information to go on but can anyone provide a
> > suggestion as to how I could proceed?
> 
> Here is what you could do:
> 
> First check if the loop happens before startup,
> or in the valgrind code,
> or in the guest code.
> 
> So, first thing to try is to run with more tracing, e.g. with
>    --trace-flags=00100000
> and/or with
>    -v -v -v -d -d -d
> 
> If the guest code starts executing, then you should e.g.
> see things such as 
> 
> ==== SB 0 (evchecks 0) [tid 1] 0x4000d00 UNKNOWN_FUNCTION /lib/i386-linux-gnu/ld-2.19.so+0xd00
> ==== SB 1 (evchecks 1) [tid 1] 0x4004330 _dl_start+16 /lib/i386-linux-gnu/ld-2.19.so+0x4330
> ...
> 
> After that, when no progress is visible, you can use vgdb (and/or gdb+vgdb) to
> see if the loop is in the guest code.
> E.g., from the shell, do (several times): 
>     vgdb v.info scheduler
> That should show where it loops
> (and if it loops, you could investigate using gdb+vgdb).
> 
> If vgdb cannot connect, then probably the loop is in the valgrind 'core'.
> You can then maybe see where in the valgrind code it is looping, by using
> gdb and directly attaching to the executable.
> 
> Philippe
> 
>