Messages in this thread | | | Date | Tue, 21 Jan 2014 13:53:06 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH 5/5] lockdep: pack subclass/trylock/read/check into a single argument |
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On Tue, 21 Jan 2014 19:43:10 +0100 Oleg Nesterov <oleg@redhat.com> wrote:
> On 01/21, Dave Jones wrote: > > > > 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 ? > > Do you mean __attribute__((packed)) ? >
I think Dave means:
unsigned char subclass : 3; unsigned char trylock : 1; unsigned char read : 2; unsigned char check : 1;
-- Steve
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