[M3devel] ppc_linux hanging

[Tony Hosking]

Is there something about the memory model on PPC?  It manifests as a hang, correct?

On 3 Jul 2010, at 06:37, Jay K wrote:

> 
> Alas, good news, bad news, restoring volatile on every load/store seems to fix this.
> I wasn't even optimizing.
> 
> Tony any ideas?
> 
> I386_LINUX is ok. AMD64_DARWIN is ok.
> SOLgnu is ok, but that doesn't count. I left volatile on there, was worried for some reason about interaction with stack walker, I forget.
> 
> So far the debugger is being very uncooperative, can't set any breakpoints..it works for C.
> 
> Aha.. 
> 
> gcc -gstabs+ -fPIC -pie 2.c
> (gdb) break main
> Breakpoint 1 at 0x658: file 2.c, line 3.
> (gdb) run
> Starting program: /home/jay/a.out 
> Warning:
> Cannot insert breakpoint 1.
> Error accessing memory address 0x658: Input/output error.
> 
> 
> (gdb) q
> The program is running.  Exit anyway? (y or n) y
> jay at plin:~$ gcc -gstabs+ -fPIC 2.c
> jay at plin:~$ gdb ./a.out
> GNU gdb 6.8-debian
> Copyright (C) 2008 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "powerpc-linux-gnu"...
> (gdb) break main
> Breakpoint 1 at 0x10000448: file 2.c, line 3.
> (gdb) run
> Starting program: /home/jay/a.out 
> 
> Breakpoint 1, main () at 2.c:3
> 3    }
> 
> 
> So lame..
> 
>   - Jay
> 
> ----------------------------------------
>> From: jay.krell at cornell.edu
>> To: m3devel at elegosoft.com
>> Subject: ppc_linux hanging
>> Date: Fri, 2 Jul 2010 08:10:10 +0000
>> 
>> 
>> Alas, PPC_LINUX is very prone to hang on head.
>> e.g. compiling m3front.
>> It doesn't hang with @M3nogc.
>> The stack at the time just shows junk, no symbols at all.
>>  and info threads shows nothing, maybe I mistyped it.
>> 
>> 
>> I'll try to figure it out.
>> The biggest recent change I think is removing volatile so I'll start
>> by trying with that put back.
>> 
>> 
>> Also I use Darwin more lately, which has its own thread suspension code.
>> Could be something broke the others.
>> 
>> 
>> Later,
>> - Jay
>> 
>> 
>