Re: While waiting for Fedora 14, a question for the engineering types re: searching and finding

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Quoting Marko Vojinovic <[email protected]>:

> On Thursday, October 28, 2010 21:36:58 you wrote:
>> On Thursday, October 28, 2010 19:27:16 William Case wrote:
>> > How does the cpu search and find stuff?
>> >
>> > There is a huge amount of searching and finding of text in
>> > memory, conditional statements requiring comparisons, and the use of
>> > entry points but not exact addresses from within both kernel space and
>> > user space.  It has occurred to me that a there is necessarily a lot of
>> > physical or bit comparing going on.  Too much, I would think, to keep
>> > dumping a search criteria into a cpu register and then replacing the
>> > contents of a second register from a block of memory until one matches.
>>
>> Believe it or not, in a nutshell that's exactly what is happening.
>
> By the way, the sheer inefficiency of that searching algorithm (ie.  
> what you are
> complaining about) is _precisely_ one of the reasons why quantum  
> computers are
> so interesting (the other reason is the number factorization into  
> primes). But
> that's going a bit off-topic, I guess... ;-)
>
> Best, :-)
> Marko

surely the kernel folks know about boyer-moore and other much better  
algorithms

http://en.wikipedia.org/wiki/Boyer%E2%80%93Moore_string_search_algorithm

Dave

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