Re: [PATCH 5/5] lockdep: pack subclass/trylock/read/check into asingle argument

[Dave Jones]

On Tue, Jan 21, 2014 at 03:10:22PM +0100, Peter Zijlstra wrote:
 > 
 > I tried the below but filed to see my vmlinux shrink, maybe I'm just not
 > building the right kernel, or otherwise GCC is stupid.
 > 
 > -extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 > -			 int trylock, int read, int check,
 > -			 struct lockdep_map *nest_lock, unsigned long ip);
 > +struct lockdep_acquire_flags {
 > +	unsigned long subclass : 3;
 > +	unsigned long trylock  : 1;
 > +	unsigned long read     : 2;
 > +	unsigned long check    : 1;
 > +};
 
As it's only 7 bits here, could we pack them into a char ?

	Dave

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