From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Subject: [ltt-dev] [URCU PATCH] Optimize caa_get_cycles() for PowerPC64
Date: Fri, 9 Sep 2011 01:34:56 -0400 [thread overview]
Message-ID: <BLU0-SMTP95A14973169504D3E0B70B96010@phx.gbl> (raw)
In-Reply-To: <1315497752-4742-1-git-send-email-tuliom@linux.vnet.ibm.com>
* Tulio Magno Quites Machado Filho (tuliom at linux.vnet.ibm.com) wrote:
> Make caa_get_cycles() read from the Time Base register with only 1 instruction.
Merged,
I did a small coding style change to the patch, turning the
#if/#else/#endif into multiple function implementations rather than
affecting the cody of the same function.
Thanks!
Mathieu
>
> Signed-off-by: Tulio Magno Quites Machado Filho <tuliom at linux.vnet.ibm.com>
> ---
> urcu/arch/ppc.h | 11 +++++++++++
> 1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/urcu/arch/ppc.h b/urcu/arch/ppc.h
> index d7317bb..2b606d0 100644
> --- a/urcu/arch/ppc.h
> +++ b/urcu/arch/ppc.h
> @@ -48,10 +48,20 @@ extern "C" {
> rval; \
> })
>
> +#define mftb() \
> + ({ \
> + unsigned long long rval; \
> + asm volatile("mftb %0" : "=r" (rval)); \
> + rval; \
> + })
> +
> typedef unsigned long long cycles_t;
>
> static inline cycles_t caa_get_cycles (void)
> {
> +#ifdef __powerpc64__
> + return (cycles_t) mftb();
> +#else
> long h, l;
>
> for (;;) {
> @@ -62,6 +72,7 @@ static inline cycles_t caa_get_cycles (void)
> if (mftbu() == h)
> return (((cycles_t) h) << 32) + l;
> }
> +#endif
> }
>
> #ifdef __cplusplus
> --
> 1.7.4.4
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
prev parent reply other threads:[~2011-09-09 5:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-08 16:02 Tulio Magno Quites Machado Filho
2011-09-09 5:34 ` Mathieu Desnoyers [this message]
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