Re: shared memory between 32bit & 64bit applications

[Keith Owens <kaos@ocs.com.au>]

On Mon, 3 May 2004 14:25:11 +0100, 
Matthew Wilcox <willy@debian.org> wrote:
>Nope.  You're being bitten by different struct padding rules.
>
>#include <stdio.h>
>
>struct foo {
>        int req;
>        long long id;
>        int abc;
>};
>
>int main(void) { return printf("%d\n", sizeof(struct foo)); }
>
>On ia64, this prints 24; on i386 it prints 16.
>
>You could declare it __attribute__((packed)) or you could reorder the
>elements in the struct to put the largest elements first.

Or compile i386 code with -malign-double which will align i386 long
long values on 8 byte boundaries, the same as ia64.