RE: why use memcpy when memmove is there?

["David Schwartz" <davids@webmaster.com>]

> Hi, All
>
> We were looking at  "[kernel]/lib/string.c"
> (http://lxr.linux.no/source/lib/string.c#L500)
>
> memcpy copies a part of memory to some other location
> but It will not work for all cases of overlapping
> blocks.(if the start of destination block falls
> between the source block)
>
> while memove copes with overlapping areas.
>
> then why is memcpy present in the sources can't we
> simply do
>
> "#define memcpy memmove" in include/linux/string.h
>
> or am I missing something?

Suppose you have two vehicles, an economy car and a semi truck. The truck
can go everyplace the car can go, and the truck can carry a bigger load. So
why would you ever use the car? Answer: The car uses less gas and you don't
always need a truck.

Think about what it takes to be able to copy one block of memory to another
location when those locations might overlap. You don't always need that.

DS


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/