Re: [HACKERS] s_lock.h problem on S/Linux

>
> David,
>
> After making your suggested changes and then doing a "make s_lock_test"
> I get the following error messages.
>
>
> [postgres@sparclinux buffer]$ make s_lock_test
> gcc -g -I../../../include -I../../../backend   -O2  -I../.. -DS_LOCK_TEST=1
> s_lock.c -o s_lock_test
> /tmp/cca10794.s: Assembler messages:
> /tmp/cca10794.s:290: Error: Bad expression
> /tmp/cca10794.s:290: Error: Missing ')' assumed
> /tmp/cca10794.s:290: Error: Bad expression
> /tmp/cca10794.s:290: Error: Missing ')' assumed
> /tmp/cca10794.s:290: Error: Illegal operands
> /tmp/cca10794.s:440: Error: Bad expression
> /tmp/cca10794.s:440: Error: Missing ')' assumed
> /tmp/cca10794.s:440: Error: Bad expression
> /tmp/cca10794.s:440: Error: Missing ')' assumed
> /tmp/cca10794.s:440: Error: Illegal operands
> make: *** [s_lock_test] Error 1
>
> If I compile with -save-temps and look at the s_lock.s file I see, on
> line 290:-
>
> .stabn 68,0,131,.LM9-s_lock
> .LM9:
> .LL45:
>         ldstub [[%i0]], %o0 <-------
> .stabn 68,0,134,.LM10-s_lock
> .LM10:
>         and %o0,0xff,%o0
>
>
> The double square braces look strange to me so I removed the single
> braces in s_lock.h.
>
> The modified file compiles OK and in s_lock.s I can see:-
>
> .stabn 68,0,131,.LM9-s_lock
> .LM9:
> .LL45:
>         ldstub [%i0], %o0
> .stabn 68,0,134,.LM10-s_lock
> .LM10:
>         and %o0,0xff,%o0
>
> Now I know absoloutely nothing whatsoever about SPARC (or gnu)
> assembler so the code changes could result in nothing like a
> test and set function but...
>
> [postgres@sparclinux buffer]$ make s_lock_test
> gcc -g -I../../../include -I../../../backend   -O2  -I../.. -DS_LOCK_TEST=1
> s_lock.c -o s_lock_test
> ./s_lock_test
> S_LOCK_TEST: this will hang for a few minutes and then abort
>              with a 'stuck spinlock' message if S_LOCK()
>              and TAS() are working.
>
> FATAL: s_lock(00020be8) at s_lock.c:215, stuck spinlock. Aborting.
>
> FATAL: s_lock(00020be8) at s_lock.c:215, stuck spinlock. Aborting.
> make: *** [s_lock_test] IOT trap/Abort (core dumped)
> make: *** Deleting file `s_lock_test'
>
> Running s_lock_test does result in a hang for a few minutes
> and then a "stuck spinlock" message so perhaps it's not all
> that bad. (Not sure about the core dump though :-( )
>
> Keith.

The core dump is expected. When a stuck spinlock is detected abort() is called
which makes the core dump. So it looks like it is working.

If you would, please send me the s_lock.s file and a diff for you changes
I will look at the generated code and if it looks ok will submit the patch.

Thanks,

-dg

David Gould            dg@illustra.com           510.628.3783 or 510.305.9468
Informix Software  (No, really)         300 Lakeside Drive  Oakland, CA 94612
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