Re: [PATCH v2 2/2] Xen/x86: Improve information from domain_crash_synchronous

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 09/09/13 14:45, Jan Beulich wrote:
>>>> On 09.09.13 at 14:46, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> +void asm_domain_crash_synchronous(unsigned long addr)
>> +{
>> +    if ( addr == 0 )
>> +        addr = this_cpu(last_extable_addr);
>> +
>> +    printk("domain_crash_sync called from entry.S\n"
>> +           "  fault at %p: ", _p(addr));
>> +    print_symbol("%s\n", addr);
> I'd prefer if all output went on a single line, so that grep-ing
> though a log would turn up the fault locations. Perhaps the
> "fault at" could go in parentheses at the end of the original
> message?

Certainly - I shall respin.

>
>>  #define UNLIKELY_START(cond, tag) \
>> +        .Lunlikely.entry.tag:     \
>>          j##cond .Lunlikely.tag;   \
>>          .subsection 1;            \
>>          .Lunlikely.tag:
> I have to admit that I still dislike this dead label, albeit in the v2
> shape it doesn't look as bad anymore. Nevertheless - why can't
> you just use .Llikely.tag? That is in the original function, always
> available (i.e. even - as done here - when using __UNLIKELY_END()),
> and only very slightly off (pointing past the conditional branch
> rather than at it).
>
> And if we decided to stay with it, it still ask for it to be named
> sensibly: It is not marking the entry of an unlikely code section
> (as it sits in the "normal" code flow).
>
> Jan

I suppose pointing at the end of the unlikely section is ok, but I still
prefer pointing to the actual instruction which made the decsion.

What name would you suggest? I admit that UNLIKELY_ENTRY_LABEL() is not
the best name but I couldn't think of a better name.

~Andrew

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