tracing: Add alloc_snapshot kernel command line parameter
If debugging the kernel, and the developer wants to use
tracing_snapshot() in places where tracing_snapshot_alloc() may
be difficult (or more likely, the developer is lazy and doesn't
want to bother with tracing_snapshot_alloc() at all), then adding
alloc_snapshot
to the kernel command line parameter will tell ftrace to allocate
the snapshot buffer (if configured) when it allocates the main
tracing buffer.
I also noticed that ring_buffer_expanded and tracing_selftest_disabled
had inconsistent use of boolean "true" and "false" with "0" and "1".
I cleaned that up too.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6c72381..0edc409 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -320,6 +320,13 @@
on: enable for both 32- and 64-bit processes
off: disable for both 32- and 64-bit processes
+ alloc_snapshot [FTRACE]
+ Allocate the ftrace snapshot buffer on boot up when the
+ main buffer is allocated. This is handy if debugging
+ and you need to use tracing_snapshot() on boot up, and
+ do not want to use tracing_snapshot_alloc() as it needs
+ to be done where GFP_KERNEL allocations are allowed.
+
amd_iommu= [HW,X86-64]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are: