[RFC PATCH 21/32] function_graph: Expand the max reserved data size

Masami Hiramatsu (Google)
2023-11-05T16:11:00Z

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Expand the maximum reserved data size to 32 from 4. On 64bit system,
this will allow reserving 256 bytes on the ret_stack in maximum but
that may not happen.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/fgraph.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 0b8a1daef733..e7188c67356e 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -95,7 +95,7 @@ enum {
#define FGRAPH_ARRAY_MASK ((1 << FGRAPH_ARRAY_SIZE) - 1)
#define FGRAPH_ARRAY_SHIFT (FGRAPH_TYPE_SHIFT + FGRAPH_TYPE_SIZE)

-#define FGRAPH_DATA_SIZE 2
+#define FGRAPH_DATA_SIZE 5
#define FGRAPH_DATA_MASK ((1 << FGRAPH_DATA_SIZE) - 1)
#define FGRAPH_DATA_SHIFT (FGRAPH_TYPE_SHIFT + FGRAPH_TYPE_SIZE)

@@ -113,7 +113,7 @@ enum {

#define RET_STACK(t, index) ((struct ftrace_ret_stack *)(&(t)->ret_stack[index]))

-#define FGRAPH_MAX_DATA_SIZE (sizeof(long) * 4)
+#define FGRAPH_MAX_DATA_SIZE (sizeof(long) * (1 << FGRAPH_DATA_SIZE))

/*
* Each fgraph_ops has a reservered unsigned long at the end (top) of the