Re: [PATCH] selinux: reorder inode_security_struct to increase objs/slab on 64bit

[Richard Kennedy <richard@rsk.demon.co.uk>]

On Mon, 2008-05-19 at 09:18 +1000, James Morris wrote: 
> On Sun, 18 May 2008, Richard Kennedy wrote:
> 
> > reorder inode_security_struct to remove padding on 64 bit builds
> >     
> > size reduced from 72 to 64 bytes increasing objects per slab to 64.
> >         
> > Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
> 
> Thanks, applied to 
> git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm
> 
> (Although I see a reduction from 164 to 160 bytes).
> 
> 
> - James

In that case I think you've got all the lock & mutex debugging turned
on :)
CONFIG_DEBUG_MUTEXES & CONFIG_DEBUG_LOCK_ALLOC will add a lot to the
mutex directly.

CONFIG_GENERIC_LOCKBREAK, CONFIG_DEBUG_SPINLOCK &
CONFIG_DEBUG_LOCK_ALLOC will each grow the spinlock contained in the
mutex.

However, I'm seeing all structures packed to size of 8n -- so I'd never
get a sizeof 164. Maybe that's just a platform/compiler difference ?
I'm running on AMD 64 & gcc 4.1.2


Richard