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From: "Alex Bennée" <alex.bennee@linaro.org>
To: "Emilio G. Cota" <cota@braap.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>,
	MTTCG Devel <mttcg@listserver.greensocs.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Peter Crosthwaite <crosthwaite.peter@gmail.com>,
	Richard Henderson <rth@twiddle.net>,
	Peter Maydell <peter.maydell@linaro.org>,
	Sergey Fedorov <serge.fdrv@gmail.com>
Subject: Re: [Qemu-devel] [PATCH v3 04/11] include/processor.h: define cpu_relax()
Date: Fri, 22 Apr 2016 10:35:35 +0100	[thread overview]
Message-ID: <87oa92t28o.fsf@linaro.org> (raw)
In-Reply-To: <1461107270-19234-5-git-send-email-cota@braap.org>


Emilio G. Cota <cota@braap.org> writes:

> Taken from the linux kernel.
>
> Reviewed-by: Richard Henderson <rth@twiddle.net>
> Signed-off-by: Emilio G. Cota <cota@braap.org>

License header notwithstanding:


Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  include/qemu/processor.h | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
>  create mode 100644 include/qemu/processor.h
>
> diff --git a/include/qemu/processor.h b/include/qemu/processor.h
> new file mode 100644
> index 0000000..675a00a
> --- /dev/null
> +++ b/include/qemu/processor.h
> @@ -0,0 +1,28 @@
> +#ifndef QEMU_PROCESSOR_H
> +#define QEMU_PROCESSOR_H
> +
> +#include "qemu/atomic.h"
> +
> +#if defined(__i386__) || defined(__x86_64__)
> +#define cpu_relax() asm volatile("rep; nop" ::: "memory")
> +#endif
> +
> +#ifdef __ia64__
> +#define cpu_relax() asm volatile("hint @pause" ::: "memory")
> +#endif
> +
> +#ifdef __aarch64__
> +#define cpu_relax() asm volatile("yield" ::: "memory")
> +#endif
> +
> +#if defined(__powerpc64__)
> +/* set Hardware Multi-Threading (HMT) priority to low; then back to medium */
> +#define cpu_relax() asm volatile("or 1, 1, 1;"
> +                                 "or 2, 2, 2;" ::: "memory")
> +#endif
> +
> +#ifndef cpu_relax
> +#define cpu_relax() barrier()
> +#endif
> +
> +#endif /* QEMU_PROCESSOR_H */


--
Alex Bennée

  parent reply	other threads:[~2016-04-22  9:35 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-19 23:07 [Qemu-devel] [PATCH v3 00/11] tb hash improvements Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 01/11] compiler.h: add QEMU_ALIGNED() to enforce struct alignment Emilio G. Cota
2016-04-22  9:32   ` Alex Bennée
2016-04-22  9:35   ` Peter Maydell
2016-04-22 15:50     ` Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 02/11] seqlock: remove optional mutex Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 03/11] seqlock: rename write_lock/unlock to write_begin/end Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 04/11] include/processor.h: define cpu_relax() Emilio G. Cota
2016-04-20 12:15   ` KONRAD Frederic
2016-04-20 17:16     ` Emilio G. Cota
2016-04-20 17:18       ` Peter Maydell
2016-04-20 17:32   ` [Qemu-devel] [UPDATED " Emilio G. Cota
2016-04-22  9:35   ` Alex Bennée [this message]
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 05/11] qemu-thread: add simple test-and-set spinlock Emilio G. Cota
2016-04-20 15:18   ` Richard Henderson
2016-04-20 17:17     ` Emilio G. Cota
2016-04-20 17:55       ` Richard Henderson
2016-04-20 18:11         ` Emilio G. Cota
2016-04-20 19:39           ` Richard Henderson
2016-04-21 16:24             ` Emilio G. Cota
2016-04-20 17:35   ` [Qemu-devel] [UPDATED " Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 06/11] exec: add tb_hash_func5, derived from xxhash Emilio G. Cota
2016-04-20 15:19   ` Richard Henderson
2016-04-22 12:58   ` Alex Bennée
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 07/11] tb hash: hash phys_pc, pc, and flags with xxhash Emilio G. Cota
2016-04-22 12:58   ` Alex Bennée
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 08/11] qht: QEMU's fast, resizable and scalable Hash Table Emilio G. Cota
2016-04-22 14:04   ` Alex Bennée
2016-04-24 20:01   ` Richard Henderson
2016-04-24 21:58     ` Emilio G. Cota
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 09/11] qht: add test program Emilio G. Cota
2016-04-22 14:35   ` Alex Bennée
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 10/11] tb hash: track translated blocks with qht Emilio G. Cota
2016-04-28 13:27   ` Alex Bennée
2016-04-19 23:07 ` [Qemu-devel] [PATCH v3 11/11] translate-all: add tb hash bucket info to 'info jit' dump Emilio G. Cota
2016-04-20 15:21   ` Richard Henderson
2016-04-22 14:38   ` Alex Bennée
2016-04-22 17:41   ` Richard Henderson
2016-04-22 19:23     ` Emilio G. Cota
2016-04-22 19:59     ` Richard Henderson
2016-04-22 23:57       ` Emilio G. Cota
2016-04-24 19:46         ` Richard Henderson
2016-04-24 22:06           ` Emilio G. Cota
2016-04-27  2:43             ` Emilio G. Cota
2016-04-28 16:37               ` Richard Henderson

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