ftrace: Optimize the allocation for mcount entries

commit bcea02b096333dc74af987cb9685a4dbdd820840 upstream.

If we can't allocate this size, try something smaller with half of the
size. Its order should be decreased by one instead of divided by two.

Link: https://lkml.kernel.org/r/20221109094434.84046-3-wangwensheng4@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: a79008755497d ("ftrace: Allocate the mcount record pages as groups")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 21b804f4f3253ff996f892a3dd86dede90ad1e47..5b49c0058040f9a63af08415f7cd70bf9376b8e0 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3174,7 +3174,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
                /* if we can't allocate this size, try something smaller */
                if (!order)
                        return -ENOMEM;
-               order >>= 1;
+               order--;
                goto again;
        }