On Wed, 2014-03-19 at 17:05 -0500, Scott Wood wrote: > On Wed, 2014-03-19 at 22:52 +0100, Christophe Leroy wrote: > > This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture. > > Unlike PPC64, PPC32 doesn't provide the PACA register. Therefore the > > implementation is similar to the one done in the IA64 architecture. > > It is based on additional information added to the Task Info structure. > > PACA isn't a register -- just a convention for how Linux uses a GPR. > Maybe it's time to use it on PPC32 as well?
PACA is actually a data structure and you really really don't want it on ppc32 :-) Having a register point to current works, having a register point to per-cpu data instead works too (ie, change what we do today), but don't introduce a PACA *please* :-) > > > Index: b/arch/powerpc/kernel/asm-offsets.c > > =================================================================== > > --- b/arch/powerpc/kernel/asm-offsets.c (revision 5607) > > +++ b/arch/powerpc/kernel/asm-offsets.c (revision 5608) > > @@ -167,6 +167,10 @@ > > DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); > > DEFINE(TI_TASK, offsetof(struct thread_info, task)); > > DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); > > + DEFINE(TI_AC_STAMP, offsetof(struct thread_info, ac_stamp)); > > + DEFINE(TI_AC_LEAVE, offsetof(struct thread_info, ac_leave)); > > + DEFINE(TI_AC_STIME, offsetof(struct thread_info, ac_stime)); > > + DEFINE(TI_AC_UTIME, offsetof(struct thread_info, ac_utime)); > > Doesn't this need to be protected by #ifdef > CONFIG_VIRT_CPU_ACCOUNTING_NATIVE? > > > > > #ifdef CONFIG_PPC64 > > DEFINE(DCACHEL1LINESIZE, offsetof(struct ppc64_caches, dline_size)); > > Index: b/arch/powerpc/include/asm/thread_info.h > > =================================================================== > > --- b/arch/powerpc/include/asm/thread_info.h (revision 5607) > > +++ b/arch/powerpc/include/asm/thread_info.h (revision 5608) > > @@ -43,6 +43,12 @@ > > int cpu; /* cpu we're on */ > > int preempt_count; /* 0 => preemptable, > > <0 => BUG */ > > +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE > > + __u32 ac_stamp; > > + __u32 ac_leave; > > + __u32 ac_stime; > > + __u32 ac_utime; > > +#endif > > This isn't uapi; why not use "u32"? > > Plus, it should be made clear that this is only used on 32-bit. > > > struct restart_block restart_block; > > unsigned long local_flags; /* private flags for thread */ > > > > @@ -58,6 +64,8 @@ > > .task = &tsk, \ > > .exec_domain = &default_exec_domain, \ > > .cpu = 0, \ > > + .ac_stime = 0, \ > > + .ac_utime = 0, \ > > Also needs to be ifdeffed -- which isn't going to work in a macro, so > maybe remove the ifdef from the variable declarations, or just let the > fields be initialized to zero by default. Or add PACA to 32-bit. :-) > > -Scott > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
