From: Julien Desfossez <julien.desfossez@polymtl.ca>
Date: Wed, 29 Jun 2011 21:13:49 +0000 (-0400)
Subject: Update ABI to select the output method
X-Git-Tag: v2.0-pre1~26
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=96ba7208aa8009345a525148e32f78cd8d4693ab;p=lttng-modules.git

Update ABI to select the output method

Add output selection in lttng_kernel_channel to use mmap or splice.

[ Merged, with a slight change: specified the enum values. ]

Signed-off-by: Julien Desfossez <julien.desfossez@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c
index 6327d09a..0aa2cec0 100644
--- a/ltt-debugfs-abi.c
+++ b/ltt-debugfs-abi.c
@@ -289,12 +289,24 @@ 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 ?
+				"relay-overwrite-mmap" : "relay-discard-mmap";
+		} else {
+			return -EINVAL;
+		}
 		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";
+		else
+			return -EINVAL;
 		fops = &lttng_metadata_fops;
 		break;
 	default:
diff --git a/ltt-debugfs-abi.h b/ltt-debugfs-abi.h
index 9524cb03..e5ddcfa0 100644
--- a/ltt-debugfs-abi.h
+++ b/ltt-debugfs-abi.h
@@ -21,6 +21,14 @@ enum lttng_kernel_instrumentation {
 	LTTNG_KERNEL_FUNCTION	= 2,
 };
 
+/*
+ * LTTng consumer mode
+ */
+enum lttng_kernel_output {
+	LTTNG_KERNEL_SPLICE	= 0,
+	LTTNG_KERNEL_MMAP	= 1,
+};
+
 /*
  * 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 */
 };
 
 /*