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 9758bb9cf442af640868d3a42834d06fb65064a6..42217126586c328e2f49f3eee0aaf1832c5435bb 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3178,7 +3178,7 @@ 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;
        }