Re: [RFC PATCH 2/3] powerpc: remove the last remnants of cputime_t

[Michael Ellerman <mpe@ellerman.id.au>]

Nicholas Piggin <npiggin@gmail.com> writes:
> cputime_t is no longer, converted to u64.

Would be good to have some explanation of why we had it and why we don't
need it anymore.

cheers

> diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
> index 431ae2343022..4961fb38e438 100644
> --- a/arch/powerpc/include/asm/cputime.h
> +++ b/arch/powerpc/include/asm/cputime.h
> @@ -21,23 +21,8 @@
>  #include <asm/param.h>
>  #include <asm/firmware.h>
>  
> -typedef u64 __nocast cputime_t;
> -typedef u64 __nocast cputime64_t;
> -
> -#define cmpxchg_cputime(ptr, old, new) cmpxchg(ptr, old, new)
> -
>  #ifdef __KERNEL__
> -/*
> - * Convert cputime <-> microseconds
> - */
> -extern u64 __cputime_usec_factor;
> -
> -static inline unsigned long cputime_to_usecs(const cputime_t ct)
> -{
> -	return mulhdu((__force u64) ct, __cputime_usec_factor);
> -}
> -
> -#define cputime_to_nsecs(cputime) tb_to_ns((__force u64)cputime)
> +#define cputime_to_nsecs(cputime) tb_to_ns(cputime)
>  
>  /*
>   * PPC64 uses PACA which is task independent for storing accounting data while
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index a2ab397065c6..d68de3618741 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -130,7 +130,7 @@ unsigned long tb_ticks_per_jiffy;
>  unsigned long tb_ticks_per_usec = 100; /* sane default */
>  EXPORT_SYMBOL(tb_ticks_per_usec);
>  unsigned long tb_ticks_per_sec;
> -EXPORT_SYMBOL(tb_ticks_per_sec);	/* for cputime_t conversions */
> +EXPORT_SYMBOL(tb_ticks_per_sec);	/* for cputime conversions */
>  
>  DEFINE_SPINLOCK(rtc_lock);
>  EXPORT_SYMBOL_GPL(rtc_lock);
> @@ -150,21 +150,6 @@ EXPORT_SYMBOL_GPL(ppc_tb_freq);
>  bool tb_invalid;
>  
>  #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
> -/*
> - * Factor for converting from cputime_t (timebase ticks) to
> - * microseconds. This is stored as 0.64 fixed-point binary fraction.
> - */
> -u64 __cputime_usec_factor;
> -EXPORT_SYMBOL(__cputime_usec_factor);
> -
> -static void calc_cputime_factors(void)
> -{
> -	struct div_result res;
> -
> -	div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
> -	__cputime_usec_factor = res.result_low;
> -}
> -
>  /*
>   * Read the SPURR on systems that have it, otherwise the PURR,
>   * or if that doesn't exist return the timebase value passed in.
> @@ -369,10 +354,7 @@ void vtime_flush(struct task_struct *tsk)
>  	acct->hardirq_time = 0;
>  	acct->softirq_time = 0;
>  }
> -
> -#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
> -#define calc_cputime_factors()
> -#endif
> +#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
>  
>  void __delay(unsigned long loops)
>  {
> @@ -914,7 +896,6 @@ void __init time_init(void)
>  	tb_ticks_per_jiffy = ppc_tb_freq / HZ;
>  	tb_ticks_per_sec = ppc_tb_freq;
>  	tb_ticks_per_usec = ppc_tb_freq / 1000000;
> -	calc_cputime_factors();
>  
>  	/*
>  	 * Compute scale factor for sched_clock.
> -- 
> 2.37.2