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authorMasami Hiramatsu2020-10-11 00:28:09 +0900
committerSteven Rostedt (VMware)2020-10-15 12:01:13 -0400
commitc16340971949ba6560c8e7c985bad8a180c57aa3 (patch)
treea8a959ed2bf24c5d29fd049d4fca213f04817a75
parentbbeb97464eefc65f506084fd9f18f21653e01137 (diff)
tracing/boot: Add ftrace.instance.*.alloc_snapshot option
Add ftrace.instance.*.alloc_snapshot option. This option has been described in Documentation/trace/boottime-trace.rst but not implemented yet. ftrace.[instance.INSTANCE.]alloc_snapshot Allocate snapshot buffer. The difference from kernel.alloc_snapshot is that the kernel.alloc_snapshot will allocate the buffer only for the main instance, but this can allocate buffer for any new instances. Link: https://lkml.kernel.org/r/160234368948.400560.15313384470765915015.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_boot.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 754e3cf2df3a..c22a152ef0b4 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -284,6 +284,12 @@ trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
if (tracing_set_tracer(tr, p) < 0)
pr_err("Failed to set given tracer: %s\n", p);
}
+
+ /* Since tracer can free snapshot buffer, allocate snapshot here.*/
+ if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
+ if (tracing_alloc_snapshot_instance(tr) < 0)
+ pr_err("Failed to allocate snapshot buffer\n");
+ }
}
static void __init