Re: [PATCH] Fake NUMA emulation for PowerPC

From: Balbir Singh
Date: Fri Dec 07 2007 - 17:03:27 EST


Arnd Bergmann wrote:
> On Friday 07 December 2007, Balbir Singh wrote:
>> Balbir Singh wrote:
>>> Geert Uytterhoeven wrote:
>>>> On Sat, 8 Dec 2007, Balbir Singh wrote:
>>>>> + if (strstr(p, "fake="))
>>>>> + cmdline = p + 5; /* 5 is faster than strlen("fake=") */
>>>> Really? My gcc is smart enough to replace the `strlen("fake=")' by 5, even
>>>> without -O.
>>>>
>>> Thanks for pointing that out, but I am surprised that a compiler would
>>> interpret library routines like strlen.
>>>
>> I just tested it and it turns out that you are right. I'll go hunt to
>> see where gcc gets its magic powers from.
>>
>
> Even if it wasn't: Why the heck would you want to optimize this? The function
> is run _once_ at boot time and the object code gets thrown away afterwards!
>
> Arnd <><

Cause, I see no downside of doing it. The strlen of fake= is fixed.
But having said that, I am not a purist about the approach, I just want
cmdline to point after "fake="

--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/