Re: [PATCH 01/29] tsx: Add generic noop macros for RTM intrinsics

Michael Neuling
2013-03-25T03:39:10Z

> From: Andi Kleen <ak@linux.intel.com>
>
> Add generic noop macros (act like transaction aborted) for RTM.
> The main use case is an occasional _xtest() added to generic
> code, without needing ifdefs. On x86+RTM this will use
> real TSX instructions.
>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> include/linux/rtm.h | 15 +++++++++++++++
> 1 files changed, 15 insertions(+), 0 deletions(-)
> create mode 100644 include/linux/rtm.h
>
> diff --git a/include/linux/rtm.h b/include/linux/rtm.h

RTM == restricted transactional memory. I don't understand why it's
"restricted" and why any other architecture else would call it that and
hence why Linux should call it that?

Can we just call it TM for transactional memory? Each arch can then
have their own implementation and call it what they want.

> new file mode 100644
> index 0000000..887b221
> --- /dev/null
> +++ b/include/linux/rtm.h
> @@ -0,0 +1,15 @@
> +#ifndef _LINUX_RTM
> +#define _LINUX_RTM 1
> +
> +#ifdef CONFIG_RTM_LOCKS
> +#include <asm/rtm.h>
> +#else
> +/* Make transactions appear as always abort */
> +#define _XBEGIN_STARTED 0
> +#define _xbegin() 1
> +#define _xtest() 0
> +#define _xend() do {} while (0)
> +#define _xabort(x) do {} while (0)

Similarly.. these are clearly x86 centric. Can we just call them
tmbegin, tmtest, tm... etc?

Mikey

> +#endif
> +
> +#endif
> --
> 1.7.7.6
>
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