On Fri, Mar 22, 2013 at 06:25:06PM -0700, Andi Kleen wrote:
> From: Andi Kleen <a...@linux.intel.com>
>
> For some locks that have a low chance of not aborting it's
> best to just disable transactions.
>
> Add a counter to thread_info to allow to disable tranasctions
> for the current task.
>
> I originally experimented with more complicated solutions,
> like a magic spinlock type to disable with magic type matching,
> but that was very intrusive in the locking code.
>
> This setup -- while adding a few more instructions -- is more
> flexible and seems to work quite nicely.
>
> Signed-off-by: Andi Kleen <a...@linux.intel.com>
> ---
> arch/x86/include/asm/thread_info.h | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/thread_info.h
> b/arch/x86/include/asm/thread_info.h
> index 2cd056e..91bb84e 100644
> --- a/arch/x86/include/asm/thread_info.h
> +++ b/arch/x86/include/asm/thread_info.h
> @@ -39,6 +39,7 @@ struct thread_info {
> */
> __u8 supervisor_stack[0];
> #endif
> + unsigned notxn; /* transactions are disabled */
This surely can be a bitfield like the other two below. It is basically
begging to be one.
> unsigned int sig_on_uaccess_error:1;
> unsigned int uaccess_err:1; /* uaccess failed */
> };
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
