[ltt-dev] [LTTNG-MODULES PATCH 2/2 v2] Update ABI to select the output method

[mathieu.desnoyers@efficios.com (Mathieu Desnoyers)]

* Julien Desfossez (julien.desfossez at polymtl.ca) wrote:
> Add output selection in lttng_kernel_channel to use mmap or splice.
> 
> Signed-off-by: Julien Desfossez <julien.desfossez at polymtl.ca>
> ---
>  ltt-debugfs-abi.c |   15 ++++++++++++---
>  ltt-debugfs-abi.h |    9 +++++++++
>  2 files changed, 21 insertions(+), 3 deletions(-)
> 
> diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c
> index 6327d09..5fe32a2 100644
> --- a/ltt-debugfs-abi.c
> +++ b/ltt-debugfs-abi.c
> @@ -289,12 +289,21 @@ int lttng_abi_create_channel(struct file *session_file,
>  	}
>  	switch (channel_type) {
>  	case PER_CPU_CHANNEL:
> -		transport_name = chan_param.overwrite ?
> -			"relay-overwrite" : "relay-discard";
> +		if (chan_param.output == LTTNG_KERNEL_SPLICE) {
> +			transport_name = chan_param.overwrite ?
> +				"relay-overwrite" : "relay-discard";
> +		} else if (chan_param.output == LTTNG_KERNEL_MMAP) {
> +		    transport_name = chan_param.overwrite ?

tabs vs space problem here.

> +			"relay-overwrite-mmap" : "relay-discard-mmap";
> +		}

          else ... ? (error handling)

>  		fops = &lttng_channel_fops;
>  		break;
>  	case METADATA_CHANNEL:
> -		transport_name = "relay-metadata";
> +		if (chan_param.output == LTTNG_KERNEL_SPLICE) {
> +			transport_name = "relay-metadata";
> +		} else if (chan_param.output == LTTNG_KERNEL_MMAP) {
> +		    transport_name = "relay-metadata-mmap";

tabs vs space.

> +		}

else here too.

Thanks,

Mathieu

>  		fops = &lttng_metadata_fops;
>  		break;
>  	default:
> diff --git a/ltt-debugfs-abi.h b/ltt-debugfs-abi.h
> index e3a7160..e333655 100644
> --- a/ltt-debugfs-abi.h
> +++ b/ltt-debugfs-abi.h
> @@ -22,6 +22,14 @@ enum lttng_kernel_instrumentation {
>  };
>  
>  /*
> + * LTTng consumer mode
> + */
> +enum lttng_kernel_output {
> +	LTTNG_KERNEL_SPLICE,
> +	LTTNG_KERNEL_MMAP,
> +};
> +
> +/*
>   * LTTng DebugFS ABI structures.
>   */
>  
> @@ -31,6 +39,7 @@ struct lttng_kernel_channel {
>  	uint64_t num_subbuf;
>  	unsigned int switch_timer_interval;	/* usecs */
>  	unsigned int read_timer_interval;	/* usecs */
> +	enum lttng_kernel_output output;	/* splice, mmap */
>  };
>  
>  /*
> -- 
> 1.7.4.1
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com