From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 25 May 2011 21:20:30 +0000 (-0400)
Subject: Add context management infrastructure
X-Git-Tag: v2.0-pre1~88
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=2dccf128a59b5353176277d01da4eabcc2086211;p=lttng-modules.git

Add context management infrastructure

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/Makefile b/Makefile
index d2d6cbab..169b7cdd 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,7 @@ obj-m += ltt-ring-buffer-metadata-client.o
 
 obj-m += ltt-relay.o
 ltt-relay-objs :=  ltt-events.o ltt-debugfs-abi.o \
-			ltt-probes.o ltt-core.o
+			ltt-probes.o ltt-core.o ltt-context.o
 
 obj-m += probes/
 obj-m += lib/
diff --git a/ltt-context.c b/ltt-context.c
new file mode 100644
index 00000000..cc9633ac
--- /dev/null
+++ b/ltt-context.c
@@ -0,0 +1,54 @@
+/*
+ * ltt-context.c
+ *
+ * Copyright 2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng trace/channel/event context management.
+ */
+
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
+#include "ltt-events.h"
+#include "ltt-tracer.h"
+
+struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
+{
+	struct lttng_ctx_field *field;
+	struct lttng_ctx *ctx;
+
+	if (!*ctx_p) {
+		*ctx_p = kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL);
+		if (!*ctx_p)
+			return NULL;
+	}
+	ctx = *ctx_p;
+	if (ctx->nr_fields + 1 > ctx->allocated_fields) {
+		struct lttng_ctx_field *new_fields;
+
+		ctx->allocated_fields = min_t(size_t, 1, 2 * ctx->allocated_fields);
+		new_fields = kzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL);
+		if (!new_fields)
+			return NULL;
+		if (ctx->fields)
+			memcpy(new_fields, ctx->fields, ctx->nr_fields);
+		kfree(ctx->fields);
+		ctx->fields = new_fields;
+	}
+	field = &ctx->fields[ctx->nr_fields];
+	ctx->nr_fields++;
+	return field;
+}
+EXPORT_SYMBOL_GPL(lttng_append_context);
+
+void lttng_destroy_context(struct lttng_ctx *ctx)
+{
+	int i;
+
+	for (i = 0; i < ctx->nr_fields; i++)
+		ctx->fields[i].destroy(&ctx->fields[i]);
+	kfree(ctx->fields);
+	kfree(ctx);
+}
diff --git a/ltt-events.h b/ltt-events.h
index ce030ae3..bacef0a8 100644
--- a/ltt-events.h
+++ b/ltt-events.h
@@ -125,6 +125,7 @@ struct lttng_ctx_field {
 			struct perf_event_attr *attr;
 		} perf_counter;
 	} u;
+	void (*destroy)(struct lttng_ctx_field *field);
 };
 
 struct lttng_ctx {
@@ -261,6 +262,8 @@ const struct lttng_event_desc *ltt_event_get(const char *name);
 void ltt_event_put(const struct lttng_event_desc *desc);
 int ltt_probes_init(void);
 void ltt_probes_exit(void);
+struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
+void lttng_destroy_context(struct lttng_ctx *ctx);
 
 #ifdef CONFIG_KPROBES
 int lttng_kprobes_register(const char *name,
diff --git a/probes/lttng-perf-counters.c b/probes/lttng-perf-counters.c
index cdda4833..c6620713 100644
--- a/probes/lttng-perf-counters.c
+++ b/probes/lttng-perf-counters.c
@@ -46,9 +46,24 @@ void overflow_callback(struct perf_event *event, int nmi,
 {
 }
 
+static
+void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
+{
+	struct perf_event **events = field->u.perf_counter.e;
+	int cpu;
+
+	mutex_lock(&perf_counter_mutex);
+	list_del(&field->u.perf_counter.head);
+	for_each_online_cpu(cpu)
+		perf_event_release_kernel(events[cpu]);
+	mutex_unlock(&perf_counter_mutex);
+	kfree(field->u.perf_counter.attr);
+	kfree(events);
+}
+
 int lttng_add_perf_counter_to_ctx(uint32_t type,
 				  uint64_t config,
-				  struct lttng_ctx *ctx)
+				  struct lttng_ctx **ctx)
 {
 	struct lttng_ctx_field *field;
 	struct perf_event **events;
@@ -83,22 +98,12 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
 		}
 	}
 
-	ctx->nr_fields++;
-	if (ctx->nr_fields > ctx->allocated_fields) {
-		struct lttng_ctx_field *new_fields;
-
-		ctx->allocated_fields = min_t(size_t, 1, 2 * ctx->allocated_fields);
-		new_fields = kzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL);
-		if (!new_fields) {
-			ret = -ENOMEM;
-			goto error;
-		}
-		if (ctx->fields)
-			memcpy(new_fields, ctx->fields, ctx->nr_fields - 1);
-		kfree(ctx->fields);
-		ctx->fields = new_fields;
+	field = lttng_append_context(ctx);
+	if (!field) {
+		ret = -ENOMEM;
+		goto error;
 	}
-	field = &ctx->fields[ctx->nr_fields - 1];
+	field->destroy = lttng_destroy_perf_counter_field;
 
 	field->name = "dummyname";//TODO: lookup_counter_name(type, config);
 	field->type.atype = atype_integer;
@@ -130,31 +135,6 @@ error_attr:
 	return ret;
 }
 
-struct lttng_ctx *lttng_create_perf_counter_ctx(void)
-{
-	return kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL);
-}
-
-void lttng_destroy_perf_counter_ctx(struct lttng_ctx *ctx)
-{
-	int i;
-
-	for (i = 0; i < ctx->nr_fields; i++) {
-		struct perf_event **events = ctx->fields[i].u.perf_counter.e;
-		int cpu;
-
-		mutex_lock(&perf_counter_mutex);
-		list_del(&ctx->fields[i].u.perf_counter.head);
-		for_each_online_cpu(cpu)
-			perf_event_release_kernel(events[cpu]);
-		mutex_unlock(&perf_counter_mutex);
-		kfree(ctx->fields[i].u.perf_counter.attr);
-		kfree(events);
-	}
-	kfree(ctx->fields);
-	kfree(ctx);
-}
-
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");
 MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");