Re: shmat problem

[Alex Riesen <fork0@users.sf.net>]

> Doug, thanks for the reply. I've set SHM_RND in the call and used
> "__attribute__ ((aligned(4096)))" during the the declaration of variable 
> global01_
> (as shown below) such that it is aligned on a page boundary. I'm porting 
> code that was
> written for a Unix system to Linux and the example shown below is how the 
> code is implemented on Unix.

on which exactly?

> The example included executed correctly on:
> mandrake - ? (Can't remember, but it was an old version)
> 
> but fails to work on:
> redhat - 2.2.14-5.0
> debian - 2.2.9
> mandrake - 2.4.19-16mdk
> 
> We are currently working on mandrake - kernel 2.4.19-16mdk.

You have to add SHM_REMAP to shmat flags (see definitions of SHM_ flags).

> 
> 	if ( (shmptr = shmat(shmid, &global01_, SHM_RND)) == (void *) -1)
> 		printf("shmat error: %d %s\n",errno, strerror(errno));
> 	else

add SHM_REMAP.

-alex