Re: [PATCH] nommu arch dont zero the anonymous mapping by adding UNINITIALIZE flag

From: Aubrey Li
Date: Fri Mar 30 2007 - 11:46:50 EST


On 3/30/07, David Howells <dhowells@xxxxxxxxxx> wrote:
Aubrey Li <aubreylee@xxxxxxxxx> wrote:

> Keep the same behave as MMU but with bad performance, or keep the same
> performance as MMU but without the same behave, Which one is more
> important?

The thing to do is to pass a flag to mmap() to suppress the memset (as
suggested). This can then be used by the uClibc malloc() implementation and
does not impact any application that does an anon mmap() expecting the memory
returned to be zeroed.


As Mike mentioned, it implies breakage in POSIX behavior
and is specific to no-mmu only.

What kind of application does an anonymous mmap() expecting the memory
returned to be zeroed?

-Aubrey
-
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/